Haynes Fuel Injection Manual 1978 to 1989 1850105901, 9781850105909

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Fuel

Injection Manual Test procedures, service adjustments

and fault diagnosis for petrol fuel injection systems Peter Coombes © Haynes Publishing Group 1989 Printed

by J.H. Haynes & Co. Ltd., Sparkford,

Nr Yeovil, Somerset

BA22 7JJ, England

All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage or retrieval system, without permission in writing from the copyright holder.

ISBN 1 85010 590 1 British Library Cataloguing

in Publication

Data

Coombes, Peter

ronsT

Haynes fuel injection manual. 1. Cars. Fuel injection systems

|. Title 629.2'53 ISBN 1-85010-590-1 Whilst every care is taken to ensure that the information in this book is correct, no liability can be accepted by the compilers or publishers for loss, damage or injury caused by any errors in, or omissions from, the information given.

i WEF SNSSN

Haynes Publishing Group Sparkford

Nr Yeovil

Somerset

BA22 7JJ

England

Haynes Publications, Inc 861 Lawrence Drive Newbury

Park

California 91320

Pei

USA

or

SUTTON LEISH®F | LIBRARIL. OZ FO VO |

JUN 1991 j

GI9LS 2

Contents Notes concerning the use of this Fuel Injection Manual

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Chapter 2 Using test ediipment tS eee)... 5 £32

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28

Chapter 3 Test procedures, fault diagnosis and service adjuStMENts ...........eeeeeeeeeeeeeeeeeee

39

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> 20

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ba cee«54k

Snap open throttle ........

2.24

Typical injection duration figures Note: Most vehicles and systems provide similar readings for injection duration when using millisecond or per cent scales.

35

Using test equipment EEE EEE aESSSS sag nnn

Airflow meter checks If, when carrying out the injection duration checks, it is thought that the airflow meter is faulty, it is possible to carry out static checks, using an ohmmeter to check the resistances between the terminals. The most important of these checks is to meas-

ure

the

change

in resistance

when

the

airflow meter flap is pushed open. This will result in an increase in the resistance value, but note that the change is not always progressive, and will often rise and fall as the flap is opened. A faulty unit is usually indicated by an open-circuit reading at some stage. This check is not possible on the ‘hot wire’ versions. A simple check can be carried out by noting the voltage change from the output terminal of the airflow meter. With the engine cranking or running and all connector plugs in place, by gaining access to the relevant terminal (terminal numbers are detailed in the test procedures), the voltage can be measured. Ideally, this test can be

performed using an oscilloscope lowvoltage scale, which will clearly show the change in voltage, and any faults that may exist. A voltmeter can also be used, but note that some older types may affect the airflow meter operation.

Connect the test lead to the terminal, and slowly raise the engine speed. The voltage reading is normally quite low at idle, and increases as the ariflow increases. The exact reading will depend on the system, but it normally changes from around 0.5 to 4.5 volts, or from 4.5 to around 10 volts on earlier designs. The higher readings will not normally be obtainable unless the engine can be placed under full-load. Note that on a few applications, the voltage reduces as the airflow increases. If the voltage does not change with the increase in airflow, it is likely that the airflow meter is faulty, but often it is possible to rectify problems by cleaning the assembly. The change in voltage should be instant, and if there is a delay, this usually indicates a sticking flap, which can cause flat spots. Quickly snap open the throttle, and the voltage should be seen to rise almost to the maximum value for a very brief period.

Condition Cranking (throttle closedf) Normal! idle Fast idle 3000 rpm Snap open throttle

Typical voltage (V) 1.5 to 3 (approx) 4.5to 5 5.5 to 6 6 to 7 Up to 8

Typical voltages at the airflow meter output terminal

MAP (manifold absolute pressure) Oscilloscope trace showing increase and decrease of airflow meter output voltage

S@nsors

The MAP sensors operate in a similar way to airflow meters, except that the change in voltage is caused by a change in manifold vacuum/pressure. As with the airflow meter checks, it is possible to detect the change in voltage by using an oscilloscope or compatible voltmeter. The sensor output voltage can be changed by either quickly snapping open the throttle, or where possible, with only the ignition on, vacuum can be applied to the sensor to alter the voltage reading. There is normally no rectification possible if the sensor is faulty.

voltmeter or an oscilloscope is connected to the appropriate terminal, an output voltage can be measured. The incorrect terminal will usually provide a zero volt reading or a supply voltage, which is often around 5 volts on these particular systems. If, when the engine is running and the test lead is connected, the engine stops, the test equipment is incompatible with this type of test. By noting a change in voltage as the engine warms up, it will indicate correct operation of the sensor.

/dle speed control valves Idle speed control valves are fitted to a number of injection systems, and although they all carry out similar functions, variations exist in their exact method of operation. Idle speed controls generally fall into two categories — the more complex types carry out total control of the idle speed, irrespective of load and temperature. The valves are either controlled by the injection ECU, or on earlier designs, an independent ECU is used. The valve fitted to Bosch systems or to the Ford system is able to maintain, or even increase, the idle speed when additional load is applied, or if the engine is cold. The less complex types are simply valves that are either open or closed, and are switched on or off by the ECU as and when required. An example of this type is to be found on many Honda vehicles, where a valve opens when the air conditioning is switched on. The ECU acts as a simple circuit. the earth to complete switch Therefore, there is very little in the way of electrical checks that are necessary. Check for a live feed to the component, and check that there is an earth (usually via the ECU) — refer to the appropriate wiring diagram to establish how the valve is wired. The more complex type of valve will often require a more complex test or set-up procedures, and as with many injection components, the use of an oscilloscope will be useful.

Water and air temperature sensors

AH 21258 Airflow meter with a test lead attached and typical oscilloscope voltage line

Although there are specific details in the test procedures for checking the temperature sensors, an alternative method is available. By gaining access to the sensor terminals if a digital with the plug connected,

H. 2/244.

Bosch

idle control

valve

36

Using test equipment

Dynamic checks (Bosch rotary types) The Bosch rotary idle speed controls are effectively small electric motors, designed to rotate through approximately sixty degrees. The switching of the electrical circuit is controlled by the ECU, and on earlier

versions, there were two switched circuits (with one common live) for rotating the unit in Opposing directions to position the valve. The later designs use one switched circuit with one live feed, and the motor rotates against spring tension. On both types, the switching signal can be illustrated by a waveform on the oscilloscope.

H. 21233

engine running, connect the valve terminals so that the valve closes, which will reduce the idle speed, and then adjust the idle speed screw to provide a speed approximately 150 rpm less than specified. When the valve plug is reconnected, the idle speed should be correct, and the valve will have enough capacity remaining to open when compensation is required. Note: Jhis test is not practicable on the /ater two-terminal types Static checks (Bosch rotary types) Refer to the vehicle Specifications, and note the resistances that should exist between the terminals. If the resistances are incorrect, the valve is faulty. Also refer to the details above, and if required, it is possible to supply a live feed and earth connection to make the valve function. This simulation can be carried out on the two-terminal types, but it will not provide a set-up procedure.

DWELL PERIOD

Bosch

idle control

waveform

The width of the pulse will normally be registered by a dwell meter, and whichever piece of equipment is used, when load is applied to the engine, which will force the ECU to open the valve further, a change should be detected. The waveform pulse width should visually change, or the dwell reading should change. Connect the test equipment to each of the outside terminals, on valves with three terminals. On later versions with only two terminals, one terminal will provide a Straight line on the oscilloscope at battery voltage (there will be no dwell reading), and the remaining terminal will provide the waveform or a dwell reading. It is advisable to practice this procedure on a known good vehicle, to check that the equipment is compatible with the test.

Note: /t is possible to measure the voltage at the signal terminal, and on most applications, a small change in voltage will occur when the ECU alters the signal. On some applications, there is a manually-adjustable idle speed screw, allowing a base idle speed to be set. There are specific details in the test procedures covering the method of obtaining the correct setting. An alternative procedure can,

H. 2/267

Ford idle speed control

Dynamic checks (Ford solenoid types) The Ford 2.0, 2.4, 2.8 and 2.9 engines are fitted with an idle speed control valve, which is moved by a solenoid as opposed to a motor. The valves are ECU-controlled and have a permanent live feed — the earth is switched via the ECU. Connecting an oscilloscope to the two terminals will either provide a straight line at battery voltage, or a waveform.

Yala

olin greya ---=---8 wt VOLTS H. 2/268

Ford idle speed control waveform

however, be used by disconnecting the plug

at the valve. By supplying a live feed to the centre terminal, and connecting each of the outside terminals to earth in turn, the valve can

be made

to open

and

close.

With

the

The waveform is altered when the valve is opened or closed from its normal position, and this is indicated by the change in the voltage band that the waveform occupies.

The upward or downward movement of the waveform can be detected by most digital or analogue voltmeters, although the change is fairly small. On digital meters, the voltage will be constantly changing, even if the waveform is static. It is therefore necessary to note the lowest or highest reading, and observe the change when load is applied to the engine. Static checks (Ford solenoid types) The valve can be checked by measuring the resistance across the two valve terminals when the plug is. disconnected, and comparing against the specification.

5

Additional

information

Injector fouling and injector delivery checks Injection systems demand a high standard of filtration to eliminate the risk of foreign particles entering the system and causing damage. This is very important on the K Jetronic system, due to the close tolerances used in the manufacture of the metering head components. On both K Jetronic systems and electronic systems, additional filters are fitted in the injectors, to prevent damage to the injector nozzles. This does, however, lead to other problems associated with a build-up of deposits. A gum- or lacquer-type substance builds up on the filter, with the eventual result that the fuel flow through the injector is reduced. If the deposit also collects at the injector nozzle, or at other critical points that exist on K Jetronic systems, it can have a substantial effect on system performance. There are a number of solvents commercially available, either as additives for the petrol, or for use in conjunction with simple apparatus which will force the fluid through the injectors. The symptoms associated with injection fouling are normally poor idle, and in extreme cases, poor engine performance when the engine is under load. Checking for a fouled injector can, however, present a problem. There are small independent testers available for checking injector fuel flow, but it is possible to carry out a injector fuel delivery check using diagnostic equipment, or by removing the injectors. With the engine running, it is possible to carry out a cylinder power balance check, and note the CO or HC readings when each cylinder is cut out. By referring to the Section in this Chapter dealing with injector tests (page 33), an explanation is provided of how to produce a diagnosis from the readings. Another method involves removing the

37

Using test equipment

possible that there is a damaged injector nozzle. In both cases, an injector cleaner may effect a cure, but if necessary the injector should be replaced. Also note the spray pattern from the injectors, which should appear as a cone with a fairly narrow angle. A bad spray pattern usually has a break-up in the cone shape, or the fuel does not appear as a fine spray.

Catalytic converters and Lambda Sensors

J AH. 21209 Injector spray patterns injectors from the intake manifold, and allowing them to inject fuel into calibrated containers for approximately thirty seconds or more. A comparison of the delivered fuel in each containerr will provide an indication as to whether an injector is fouled.

Cutaway view of an injector © Robert Bosch Limited

Filter Solenoid winding Solenoid armature Needle valve

Electrical AKRWY™

It is normal to allow approximately 10% variation in the fuel delivery from the injectors. If one injector is delivering significantly less than the other injectors, suspect fouling, but if the delivery is greater, it is

connection

Lambda

sensor

© Robert Bosch Limited

Contact Supporting ceramic Sensor ceramic Protective tube (exhaust ROMS side)

a 6 7

Electrical connection Disc spring Protective sleeve (air side)

8 9 10

Housing (-) Electrode (—) =Electrode (+)

In many European countries, as well as in the USA and Japan, various additional components are fitted to the fuel and exhaust systems in order to reduce exhaust emissions. During 1989, many vehicle manufacturers decided to equip vehicles with some of these components in anticipation of compulsory fitment legislation in Europe. Most notable of the additions is a catalytic converter, which is located in the exhaust system. Although it does not directly affect injection system operation, in most applications, there is an associated component which is connected to the injection system ECU. The component is known as a Lambda or Oxygen sensor. Located just downstream of the exhaust ports, it measures the oxygen level being emitted from the engine. This in turn is a reference to the mixture strength. The catalyst in the exhaust is used to burn off some of the harmful gases such as carbon monoxide (CO), hydrocarbons (HC) and some oxides of nitrogen that are produced during the combustion process. To carry out this function, however, it is necessary to maintain a fairly strict control over the mixture strength being supplied to the engine, otherwise some of the gases cannot be burnt by the catalyst. The Lambda sensor therefore supplies the ECU with the necessary information, so that if the incorrect mixture is beng supplied, it can then be altered as required. The Lambda sensor produces a small. voltage as a signal for the ECU, and if the voltage is incorrect, the ECU adjusts the injection duration to compensate. Typically the sensor output voltage, when the engine is at normal working temperature, is around 0.4 to 0.6 volts. Most digital voltmeters, and some oscilloscopes with appropriatelycalibrated scales, should be able to measure the voltage from the sensor. If the voltage is too high or too low, this normally indicates an incorrect mixture, but note that the sensor signal is often not reacted to at idle — this is referred to as ‘open-loop’ operation. When the vehicle is being driven, then the sensor signal is used by the ECU under most driving conditions, and this is referred to as ‘closed-loop’ operation.

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39

Chapter 3 Test procedures, fault diagnosis and service adjustments Introduction This Chapter provides specific details of, and basic service adjustment procedures for, the fuel injection systems fitted to individual vehicles. It also contains system and component test procedures, and fault diagnosis tables, for the individual fuel injection systems covered by this manual. For model-specific information, refer to the contents list at the front of this manual in the first instance. The Chapter is divided into sections, each covering one of the main fuel injection systems. Each section starts with a group of specification tables, underbonnet layout diagrams, and basic idle speed and

mixture (CO) adjustment procedures, which relate to specific vehicle models. The remainder of each section is devoted to system and component test procedures for each fuel injection system. At the end of each section there appears a table for ECU fault diagnosis (where applicable), a general fault diagnosis table, and a number of system wiring diagrams. The fuel injection systems covered, and the pages on which the main parts of each relevant section can be found, are listed by system below:

Specifications underbonnet views and service

Test

ECU

System type

adjustments

procedures

checks

Fault diagnosis

Wiring diagrams

Bosch L Jetronic

40 to 69

70 to 79

8&0

87

82 to 83

Bosch

84 to 117

718 to 126

IZ 7,

128

129 to 137

Bosch LE3 Jetronic

132 to 141

742 to 148

148

149

150 to 157

Bosh LH Jetronic

faZto-J6i

162 to 168

169

170

171 to 173

Bosch Motronic (early series)

174 to 189

790 to 198

199

200

207 to 203

Bosch Motronic (late series)

204 to 219

220 to 226

2e7,

228

229 to 237

Bosch K Jetronic

232 to 295

296 to 304

305

306 to 307

Bosch

KE Jetronic

308 to 315

316 to 323

324

325

O20 10 O27

Ford EECIV series

BLGaLO DOO

334 to 340

341

342

343 to 344

Honda PGM-FIl

346 to 363

364 to 371

372

373

374 to 375

Lucas Hot Wire (LH)

376 to 381

382 to 387

388 to 389

390

391 to 393

Lucas LH Engine Management

394 to 395

396 to 407

402

403

404 to 405

Lucas P Digital

406 to 409

410 to 415

416

417

418 to 420

Mazda

422 to 425

426 to 432

433

434

435 to 436

Nissan ECCS

438 to 445

446 to 453

454

455

456 to 457

Nissan EFI

458 to 463

464 to 471

472

473

474 to 475

Renix Injection

476 to 483

484 to 490

491

492

493

Rover SPI (single point injection)

494 to 495

496 to 507

502

503

504 to 505

Subaru EPI

506 to 507

508 to 513

514

ay he

516

Suzuki EPI

518 to 519

520 to 524

525

526

527

Toyota EFI

528 to 537

532 to 539

540

541

542 to 543

Toyota TCCS

544 to 5517

552 to 560

567

562

563 to 565

VW Digifant

566 to 567

568 to 572

573

574

575 to 576

Weber IAW

578 to 583

584 to 589

590

shetl

592

LE/LE2 Jetronic

EGI

40 Alfa Romeo

BOSCH

L JETRONIC

Refer also to page 39

Alfa 6 2.51 84 to 86; Alfa 75 2.5 V6 86 to 89; Alfa 75 3.01 V6 87 to 89; Alfa 90 85 to 87; GTV 6 2.5 87 to 87

SPECIFICATIONS N = Non-adjustable

M = Manual

AT =Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

t+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

800 to 1000

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

QdstorkeS

Water temperature sensor:

C35 (2F) 10 (50) 20 (68) 80 (176)

Air temperature sensor:

poo

CO at 3000 rpm (%) HC at idle (ppm)

(Pins 6 & 27 in

O (32)

Airflow meter)

Injection duration checks

tfy

20

(68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve _| Test terminals

4.2/200 Small duration

Engine cold:

Throttle position switch/sensor

Zl Large duration

ms

%

degrees

Similar to, or above, idle values 4

6.66

3.99

ms

%

degrees

3.74

2.24

2.4

4.00

2.40

2.3

7.66

4.59

Zid

11.00

6.60

> 20

> 12

ohms

= ieRhy

Infinity

Ze Ve"

0 to 10

so 137

0 to 10

2

Infinity

AST

Test terminals

ohms

W & Switch body

Similar to, or above, idle values Fane

|Test terminals

Airflow meter/MAP sensor

< 30°C/86*F

0 to 10

Test terminals

ohms

39 & 36

39, 36 649 (9 -9527

(Flap closed)

Infinity

39 & 36

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min)....

2.2 to 2.7 (32 to 39) 1.5 to 2 (2.6 to 3.5)

en

W.21206

(Flap open)

0 to 10

6&8

130 to 260

7&6

Up to 1000

Alfa Romeo

BOSCH

L JETRONIC

Alfa 6 2.51 84 to 86; Alfa 75 2.5 V6 86 to 89; Alfa 75 3.0i V6 87 to 89; Alfa 90 85 to 87; GTV 6 2.5 87 to 87

Airflow sensor MAP sensor Throttle position switch/sensor

Auxiliary air valve [dle speed control valve Injectors Thermotime switch ECU (under facia) Water temperature sensor ARWNH™ DANA 70 Air temperature sensor 771 Pressure regulator 72 Relays 713 Cold start injector 74 Warm-up regulator 75 Vacuum/pressure switch 716 Fuel filter (at rear of vehicle) 77 Metering head 78 /njector resistors 719 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H. 21001

H.19269

H.19268

a

CO (mixture) adjustment

2

Idle speed adjustment 1

CO (mixture) adjuster screw

Idle bypass-adjuster screw

Ensure engine is at normal operating temperature, and approximately twenty seconds at around 2000 rpm before the idle speed. Locate the idle adjuster on the intake plenum and slacken the locknut. Adjust the idle nut ‘1’ to obtain the idle speed, and re-tighten the locknut.

run it for adjusting chamber, specified

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

42

BOSCH

BMW

Refer also to page 39

L JETRONIC

520i 87 to 83

SPECIFICATIONS AT = Auto

M = Manual

N = Non-adjustable

N/A = Not available/applicable

t+ = Throttle open

* = Throttle closed

Static checks

Dynamic checks

Resistance characteristics

Basic checks Idle speed (rpm)

850 + 50

Injectors (ohms)

800 + 50 (Sept ‘82 on)

Cold start injector (ohms) Auxiliary air valve (ohms)

1°

Water temperature sensor:

:

CO at idle (%)

(between terminals)

CR ACF (50)

164.

(68) 20 80 (176) CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

SC

(Pins 6 & 27 in

O (32)

Airflow meter)

Injection duration checks

(CF)

20

(68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve

_|Test terminals

Throttle position switch/sensor

|Test terminals

ohms

Sete B=

Infinity

Fata id Be iy

0 to 10

Jvttal OF

0 to 10

2 & 18+

Infinity

Test terminals

ohms

H.2/199

ge Small duration

Large duration

Engine cold:

ms

% degrees Similar to, or above, idle values 3.99 6.66 4

ms

%

H.21203

W & Switch body

degrees

Similar to, or above, idle values

2S

3.74

2.24

2.4

4.00

2.40

Paes

7.66

4.59

ote

11.00

6.60

> 20

> 12

Airflow meter/MAP sensor

39 36 6 9 8 7 27

Fuel system checks Fuel pressure - regulator vacuum

pipe

disconnected - bar (Ibf/in?)

3 (43) nominal

Pump delivery - litres/min (pints/min)....

2.2 (3.9) nominal

W.21206

< 30°C/86°F

0 to 10

Test terminals

ohms

39 & 36*

Infinity

39 & 36t

0 to 10

6&8

130 to 260

7&6

Up to 1000

BMW

BOSCH

L JETRONIC

520i 87 to 83

Airflow sensor MAP sensor Throttle position switch/sensor

Auxiliary air valve Idle speed control valve /njectors Thermotime switch ECU (under facia) Water temperature sensor WOANDARWBH™ 70 Air temperature sensor 771 Pressure regulator 72 Relays 713 Cold start injector 14. Warm-up regulator 75

Vacuum/pressure switch

16 17 78 79 20

Fuel filter (at rear of vehicle) Metering head Injector resistors Load enrichment device Additional idle control valve

Not all items fitted to all models

E

H.19390

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

44

BOSCH

BMW

L JETRONIC

Refer also to page 39

525i 79 to 82: 528i 77 to 82

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

t+ = Throttle open

Static checks

Dynamic checks

Resistance characteristics

Basic checks Idle speed (rpm)

Injectors (ohms)

900 + 50

Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

1 + 0.5 (525i) 0.5 to 2 (528i)

Water temperature sensor:

°C

IF)

(between terminals)

10

(50)

20

(68)

80 (176) CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

2G

O (32) 20 (68)

(Pins 6 & 27 in Airflow meter)

Injection duration checks

(°F)

Refer to Chapter 2 Injection waveform

H.2/200

Test terminals

Throttle position switch/sensor

|Test terminals

H. 2/199

Small duration

Engine cold:

Auto idle speed control valve

3G

Large duration

ms

%

degrees

1.21203

13*

ohms Infinity

Haga BCb= he

0 to 10

3 & 18t

0 to 10

21

Infinity

St

Similar to, or above, idle values

4

6.66

3:99

ms

%

degrees

Test terminals W & Switch body

Similar to, or above, idle values

ood

3.74

2.24

1000 rpm

2.4

4.00

2.40

2000 rpm

Zu

7.66

4.59

2.2

11.00

6.60

> 20

Ad 2

ohms

Airflow meter/MAP sensor

39ues6n Ge Se Oeetaee?

< 30°C/86°F

Oto 10

Test terminals

ohms

39 & 36*

Infinity

39 & 36t

0 to 10 130 to 260 Up to 1000

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

3 (43) nominal 2.2 (3.9) nominal

H.2/206

BMW

BOSCH

L JETRONIC

525i 79 to 82; 528i 77 to 82

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve Idle speed control valve /njectors Thermotime switch ECU (under facia)

mls | (Of

OANDAAWBN™ Water temperature

sensor 10 Air temperature sensor

77 72 713 714 75 76 17 78 79 20

Pressure regulator Relays Cold start injector Warm-up regulator Vacuum/pressure switch Fuel filter (at rear of vehicle) Metering head Injector resistors Load enrichment device Additional idle control valve

Not all items fitted to all models

H.19390

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

46

BOSCH

BMW

L JETRONIC

Refer also to page 39

628 CSi 79 to 82; 728i 79 to 82

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

900 + 50

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Water temperature sensor: (between terminals)

CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

(Pins 6 & 27 in Airflow meter)

Injection duration checks Refer to Chapter 2 Injection waveform

H. 2/199

4.21200

Test terminals

Throttle position switch/sensor

|Test terminals

ohms

3) & 18?

Infinity

2&3 13t

0 to 10

SG? TST

0 to 10

2.8) 18F

Infinity

Test terminals

ohms

Large duration

Small duration

Engine cold:

Auto idle speed control valve

ms

%

degrees H.21203

Similar to, or above, idle values

o

6.66

3:99

ms

%

degrees

W & Switch body

Similar to, or above, idle values

2.5

3.74

2.24

2.4

4.00

2.40

23

7.66

4.59

Bae,

1 1.00

6.60

> 20

meV

Airflow meter/MAP

sensor

399 368 GE 99 687927

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min) ....

3 (43) nominal 2.2 (3.9) nominal

H. 21206

< 30°C/86°F

Oto 10

Test terminals

ohms

391&336*

Infinity

SUEiSST

0 to 10

6&8

130 to 260

7&6

Up to 1000

BMW

BOSCH

L JETRONIC

628 CSi 79 to 82; 728i 79 to 82

1/10

6 313 Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve Idle speed control valve Injectors Thermotime switch ECU (under facia) Water temperature sensor AARWBNH™ MOANA 70 Air temperature sensor 71 Pressure regulator 72 Relays 713 Cold start injector 74 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not al/ items fitted to all models 1H. 21073

(6

ce H.19390

ee

XX H.19327

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

48

BMW

BOSCH

L JETRONIC

Refer also to page 39

635 CSi 78 to 82: 732i 79 to 82; 733i 76 to 79; 735i 79 to 82

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

850 + 50 (635i) 300 4 50

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

0.3 to 1.5

Water temperature sensor: (between terminals)

oC. | (PF) 1.0 7 (50) 20 (68) 80 (176)

Air temperature sensor:

[Cc

CO at 3000 rpm (%) HC at idle (ppm)

(Pins 6 & 27 in

O (32)

Airflow meter)

Injection duration checks

VCR)

20

(68)

Refer to Chapter 2

Injection waveform

g

_‘|Test terminals

Throttle position switch/sensor

|Test terminals

H. 2/199

4.21200 Small duration

Engine cold:

Auto idle speed control valve

3G

Large duration

ms

%

zi

degrees

g

iesons

Similar to, or above, idle values 4 6.66 3.99 ms

%

Similar to, or above, idle values

3.74

2.24

2.4

4.00

2.40

Fie | ie

7.66

4.59

11.00

6.60

> 20

> 12

Airflow meter/MAP sensor

39 36 6 9 8 7 27

Fuel pressure - regulator vacuum

Infinity

Pate hot:

Oto 10

3 & 18t

0 to 10

2 & 18+

fa) Infinity

Test terminals

ohms

< 30°C/86°F

0 to 10

Test terminals

ohms

39 & 36*

Infinity

39 & 36t

0 to 10

6&8

130 to 260

Up to 1000

Fuel system checks disconnected - bar (Ibf/in2)

182

W & Switch body

degrees

20

ohms

pipe

Pump delivery - litres/min (pints/min)....

3 (43) nominal 2.2 (3.9) nominal

=

H. 2/206

BMW

BOSCH

L JETRONIC

Bao Gol 76-10 82;/732i 79 to 82; 733i 76 to 79; 735i 79 to 82

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed contro! valve /njectors Thermotime switch ECU (under facia) Water temperature sensor OANAARWBH™ CoH

( HET

LS

}

AL

70

Air temperature sensor

72 73 714. 15 76 77 78 79 20

Relays Cold start injector Warm-up regulator Vacuum/pressure switch Fuel filter (at rear of vehicle) Metering head Injector resistors Load enrichment device Additional idle control valve

17 Pressure regulator

Not all items fitted to all models

H.19390

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1° on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

50

Citroen

BOSCH

L JETRONIC

Refer also to page 39

CX 2400 Injection 77 to 8&3

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

‘+ = Throttle open

Static checks Resistance characteristics

Basic checks Idle speed (rpm)...........

800 to 900

injectors*(ohms) ahs .~that. < nth

2 to 3

Cold start injector (ohms)

4

.......

Auxiliary air valve (ohms)........ Ci) atidie (%) .....222

0.8 to 1.5

Water temperature sensor:

°C £ (°F)

ohms

10

(50)

4000

80 (176)

300

20 CO at 3000 rpm (%).......

20

>d5

CER ne MDD

MORE

Test terminals

Pao:

ohms

W & Switch body

Similar to, or above, idle values

,

TST

Airflow meter/MAP

sensor

< 30°C/86°F

0 to 10

Test terminals

ohms

39 & 36 39136" 6) 96a e27

(Flap closed)

Infinity

39 & 36

Fuel system checks F

uel pressure - regulator vacuum

i

é

pipe

disconnected - bar (Ibf/in?) ..............

2.5 (36) nominal

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.5 to 3.6)

eset

cantaie 6&8

Mri 130 to 260

7&6

Up to 1000

BOSCH

Citroen

L JETRONIC

CX 2400 Injection 77 to 8&3

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve Injectors Thermotime switch ECU (under RH lower facia) Water temperature sensor WOANAARWBH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays 73 Cold start injector 714 Warm-up regulator 75 Vacuum/pressure switch 76 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

AH 2/0/2

E

eZ

——

H.20332

H.19327

Idle speed adjustment 1

CO (mixture) adjustment

Idle bypass adjuster screw 2

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the intake pipe, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate. If the vehicle is equipped with an air conditioning system, an additional idle speed valve is used to supplement the normal idle speed. With the air conditioning operating, adjust the screw on the valve to achieve an idle speed of around 850 rpm.

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

52

Citroen

BOSCH

L JETRONIC

Refer also to page 39

CX GTi & Prestige Turbo 84 to 86

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

800 to 850 M/AT

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

0:5:10 173

Water temperature sensor:

10 1150) 20 (68) 80 (176) CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

eC.

(Pins 6 & 27 in

O (32)

Airflow meter)

Injection duration checks

(°F)

20

(68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve _| Test terminals

Throttle position switch/sensor 42/200

H. 21199

Small duration

Engine cold:

Large duration

ms

%

degrees

Similar to, or above, idle values 4

6.66

AlT9

ms

%

degrees

3.74

3.36

2.4

4.00

3.60

pas)

7.66

6.89

Pad

11.00

9.90

> 20

> 18

ohms

ott? tis*

Infinity

2 & 18*

0 to 10

3 & 18f

0 to 10

21ST

Infinity

Test terminals

ohms

W & Switch body

Similar to, or above, idle values

2.5

|Test terminals

Airflow meter/MAP sensor

< 30°C/86°F

0 to 10

Test terminals

ohms

39 & 36 39

36

69

87

27

(Flap closed)

Infinity

39 & 36

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min)....

;

2.5 (36) nominal 1.5 to 2 (2.6 to 3.5)

4.21206

(Flap open)

0 to 10

6&8

130 to 260

7&6

Up to 1000

BOSCH

Citroen

L JETRONIC

CX GTi & Prestige Turbo 84 to 86

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU (under RH facia) Water temperature sensor WOANDAAARWBH™ 70 Air temperature sensor 771 Pressure regulator 72 Relays 73 Cold start injector 14 Warm-up regulator 75

Vacuum/pressure

76 17 78 79 20

Fuel filter Metering head Injector resistors Load enrichment device Additional idle control valve

switch

Not all items fitted to all models

H.20332

Idle speed adjustment 7

CO (mixture) adjustment

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the intake pipe, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate. If the vehicle is equipped with an air conditioning system, an additional idle speed valve is used to supplement the normal idle speed. With the air conditioning operating, adjust the screw on the valve to achieve an idle speed of around 850 rpm.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

54

Jaguar/Daimler

BOSCH

L JETRONIC

Refer also to page 39

XJ6, Sovereign & VDP 4.2 79 to 86

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A = Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Water temperature sensor:

°G ih(eF)

10 (50) 20 (68) 80 (176) CO at 3000 rpm (%)

HC at idle (ppm)

Air temperature sensor:

°C

(Pins 6 & 27 in Injection duration checks

AO

(°F)

O (32)

teH

20 (68)

Refer to Chapter 2

Injection waveform

ngine Engi

hse

ie)

ma

t uration

co Id:

2

: arge

ms

9%

Auto idle speed control valve

__|Test terminals

Throttle position switch/sensor

[Test terminals

t duration

-

%

aa

13%

2 &

18%

3 & 18t

degrees

2& 18t

Similar to, or above, idle values 4 6.99 3.99 ms

= = ohms

H. 2/199

Test terminals

Similar to, or above, idle values 5 FAP

E387

2.4

4.00

2.40

2.3

7.66

4.59

a P

11.00

6.66

> 20

> 12

10

Oto 10 wr

Infinity ohms

W & Switch body

degrees

210

Infinity O to

Airflow meter/MAP sensor

< 30°C/86°F

0 to 10

Test terminals

ohms

39 & 36

39 36 6 9 8 7 27

(Flap closed)

Infinity

39 & 36 Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min)....

2.5 to 2.8 (36 to 40) 1.5 to 2 (2.6 to 3.5)

a:

to 1

(FapoPeny 6&8

One 130 to 260

7&6

Up to 1000

Jaguar/Daimler

BOSCH

L JETRONIC

XJ6, Sovereign & VDP 4.2 79 to 86

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU (in boot) Water temperature sensor AARWBNH™ OANA 70 Air temperature sensor 71 Pressure regulator 72 Relays 13 Cold start injector 14. Warm-up regulator 15

Vacuum/pressure

16 17 78 19 20

Fuel filter Metering head Injector resistors Load enrichment device Additional idle control valve

switch

Not all items fitted to all models H.21026

4.12786,

H.19261

CO (mixture) adjustment

Idle speed adjustment

1

Idle bypass adjuster screw

ature, and run it for Ensure the engine is at normal operating temper adjusting the idle before rpm approximately twenty seconds at 2000 e body, and throttl the on ‘1’ er adjust s speed. Locate the idle bypas adjuster to the in . Screw remove the tamperproof plug (where fitted) the speed. se increa to er decrease the idle speed, or unscrew the adjust riate. approp Fit a new tamperproof plug where

2

CO (mixture) adjuster screw

ature, and run it at Ensure the engine is at normal operating temper seconds. With the engine approximately 2000 rpm for around twenty er ‘2’ on the airflow adjust CO at the correct idle speed, locate the fitted). Using either e (wher plug f rproo meter, and remove the tampe er to increase the CO, an Allen key or screwdriver, screw in the adjust Set the CO reading to or unscrew the adjuster to reduce the CO level. plug. f that specified, and fit a new tamperproo

56

Lancia

BOSCH

Beta 2000

L JETRONIC

Refer also to page 39

ie 82 to 85

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)...........

950 + 50

Injectors (OWMS)i.w.

eas bah b nbs lok .......

Cold start injector (ohms)

2 to 3 4

Auxiliary air valve (ohms)........

Ed at idle (2). «11.5.3... 209%

2 to 3

CO at 3000 rpm (%).......

410.75

BE at idle (PPR oer snaseasts

eee

Water temperature sensor:

°C

ASF)

ohms

80 (176) Air temperature sensor:

(Pins 6 & 27 in

Injection duration checks

Airflow meter)

°C

(°F)

ohms

O

(32)

6000

20 (68)

2000

Refer to Chapter 2

Injection waveform

H.2/200

7

palpe cold : Engi

ms

y%

Similar to, or above, idle values

4

bee Speer eee

Engine warm:

ms

on a's wight sag

ae

AL

%

;

gee

2.4

4.00

3.60

ae eR

Infinity Oto 16

3 & 18t

0 to 10

2 & 18+

infinity

Test terminals

a

aa

7.66

6.89

ee

22

11.00

9.99

Snap open throttle........

>6

> 20

> 18

ohms

W & Switch body

Similar to, or above, idle values

ae

2.36

ee

3 & 18% See

degrees

3.74

peaks

ohms

5.99

25

rT

oo

6.66

a

oe

[Test terminals

degrees

at

A

Throttle position switch/sensor

aes a rge durati ration

Cranking . ...Siccosuaaeeet

er

Test terminals

H. 21199

“tn Sa m all duration ratio

MN

Auto idle speed control valve

Airflow meter/MAP sensor

EZo

mad i:

Airflow meter/MAP sensor

< 30°C/86°F

0 to 10

Test terminals

ohms

39'S 36 39

36

(Flap closed)

66 $9 8677227

SO

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2.8 to 3 (40 to 44) 1.5 to 2 (2.6 to 3.5)

ohms

be

Infinity

SO

(Flap open)

0 to 10

6&8

130 to 260

7&6

Up to 1000

Lancia Gamma

BOSCH

L JETRONIC

2.5 82 to 85

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve Idle speed control valve /njectors Thermotime switch ECU (under facia) Water temperature sensor DANDAAARWH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays 713 Cold start injector 74 Warm-up regulator 75 Vacuum/pressure switch 76 Fuel filter 17 Metering head 78 Injector resistors 719 Load enrichment device 20 Additional idle control valve Not all items fitted to all models H.21029

6

| 7111/10

13°9

Ss

=

.

th

H.25232

CO (mixture) adjustment

Idle speed adjustment

1

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

60

Morgan

BOSCH

L JETRONIC

Refer also to page 39

Plus 8 Fi 83 to 89

SPECIFICATIONS AT = Auto

M = Manual

N = Non-adjustable

N/A

= Not available/applicable

{ = Throttle open

* = Throttle closed

Dynamic checks

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

825+

50M

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Water temperature sensor:

Gy

(FE)

1:03 1(50) 20 (68) 80 (176) CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

"Cy

(Pins 6 & 27 in

O (32)

Airflow meter)

Injection duration checks

(7?)

20

(68)

Refer to Chapter 2 Injection waveform

42/200

Test terminals

Throttle position switch/sensor

|Test terminals

ohms

Sate ie

Infinity

2G

0 to 10

. 2/199

Small duration

Engine cold:

Auto idle speed control valve

Large duration

ms

%

degrees

Similar to, or above, idle values 4 6.66 2.99 ms

%

1.50

2.4

4.00

1.80

pees

7.66

3.44

22

11.00 > 20

4.95 >9

Oto 10

2a

Infinity

ST

ohms

W & Switch body Ko)

Similar to, or above, idle values

33

creer Whore

Test terminals

degrees

2:5

BE

Airflow meter/MAP sensor

C7 BO

Test terminals

0 to 10

ohms

39 & 36 99

36 6 9 8.7827

(Flap closed)

Infinity

S236

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in?)

,

pipe

Pump delivery - litres/min (pints/min)....

2.5 to 2.8 (36 to 40) 1.5 to 2 (2.6 to 3.5)

jhe

(Flap open)

0 to 10

6&8

130 to 260

7&6

Up to 1000

BOSCH

Morgan

L JETRONIC

Plus 8 Fi 83 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed contro/ valve /njectors Thermotime switch ECU (in passenger footwell) Water temperature sensor ARWBNH™ WOMNA 70 Air temperature sensor 77 Pressure regulator 72 Relays 13 Cold start injector 14 Warm-up regulator 715

Vacuum/pressure

76 17 78 79 20

Fuel filter Metering head Injector resistors Load enrichment device Additional idle control valve

switch

Not al/ items fitted to al// models

1/S3ED

&

Idle speed and CO (mixture) adjustment 7 2

Idle speed adjustment Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate. Note that on some vehicles, the adjuster is located closer to the throttle position sensor, and has a locknut, which should be slackened before the adjuster can be altered.

Idle bypass adjuster screw CO (mixture) adjuster screw

CO (mixture) adjustment

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

62

Opel

BOSCH

Ascona/Manta

2.0 77 to 87: Rekord

L JETRONIC

Refer also to page 39

2.0 77 to 87

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A = Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

850 to 900

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

:

Water temperature sensor:

CO at 3000 rpm (%) HE at idle (ppm)

Air temperature sensor:

Injection duration checks

Airflow meter)

(Pins 6 & 27 in

Refer to Chapter 2 Injection waveform

Ce

g

Test terminals

Throttle position switch/sensor

|Test terminals

ohms

3.4167

Infinity

2 &)18*

0 to 10

3 & 18T

0 to 10

2 os ST

Infinity

Test terminals

ohms

H. 2/199

Small duration

Engine cold:

Auto idle speed control valve

Large duration

ms

N

3

degrees

g

21203

Similar to, or above, idle values 4

6.66

5.99

ms

%

degrees

W & Switch body

Similar to, or above, idle values

2.5

3.74

3.30

2.4

4.0

3.60

23

7.66

6.89

22

11.00

9.90

> 20

> 18

Airflow meter/MAP sensor

20

> 12

Airflow meter/MAP sensor

20

>9

tae

Infinity

Zur 1%

0 to 10

3 & 18t

0 to 10

Pgs 9toale §

Infinity

Test terminals

ohms

W & Switch body 18

8&5

W & Switch body Engine warm: Cranking .. 03. ess Ole o.oo hs yeaah

ea SEE ogre tee 2000 rpm... .7oae ere

é AY Similar to, or above, idle values

aiabates Sebo

Airflow meter/MAP

a E eee

Fuel system checks Fuel pressure - regulator vacuum pipe disconnected - bar (Ibf/in2) ..............

3 (43) nominal

Pump delivery - litres/min (pints/min)....

2.2 (3.9) nominal

sensor

=

20

> 18

8&5

300 to 400

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2.3 to 2.7 (33 to 39) 1.5 to 2.5 (2.6 to 4.4)

Airflow meter/MAP sensor

Peugeot

BOSCH

LE/LE2 JETRONIC

505 GTi 83 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve Idle speed contro! valve Injectors Thermotime switch ECU (behind passenger facia) Water temperature sensor WOANDAALRWNH™ 70 Air temperature sensor 71 Pressure regulator 72 Relays 13 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

Idle speed and CO (mixture) adjustment 1 2

Idle bypass adjuster screw CO (mixture) adjuster screw

H.19236

CO (mixture) adjustment Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either

Idle speed adjustment

Run the engine until it is at normal operating temperature. Locate the idle screw ‘1’, and adjust to achieve the specified idle speed.

an Allen key or screwdriver, screw in the adjuster to increase the CO,

or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

12

Vauxhall Astra GT/E

BOSCH & 1.81 83 to 86: Belmont

LE/LE2 JETRONIC

Refer also to page 39

1.81 84 to 86; Cavalier 1800 82 to 86

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+t = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

900 to 950 M

Injectors (ohms)

800 to 850A

Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

0.5 to 1.5

Water temperature sensor:

°CF

ACF)

10 (50) 20 (68) 80 (176) CO at 3000 rpm (%)

HC at idle (ppm)

Air temperature sensor:

Injection duration checks

°C

(°F)

(Pins 9 & 8 in

O9(S2)

gulowarnotet]

20 (68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve _‘ [Test terminals

ie

Sad

Small duration

Engine gine co cold:

Throttle position switch/sensor

Large duration

ms

%0

d egrges

as

|Test terminals

ohms

3 & 18*

Infinity

2 GErSe*

0 to 10

cad: | 22 SMSt

0 to 10

2 & 18t

Infinity

Test terminals

ohms

Test terminals

ohms

547 8&5

250 to 1300 300 to 400

Similar to, or above, idle values 4

5.99

5.39

ms

%

degrees

Thermotime

switch

Similar to, or above, idle values 1000 rpm

3.74

3236

4.00

3.60

2000 rpm

:

7.66

6.89

3000 rpm

:

11.00

9.90 Aas

Snap open throttle

> 20

Fuel system checks Fuel pressure - regulator vacuum pipe

disconnected - bar (Ibf/in?)

2.5 to 2.7 (36 to 39)

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP sensor

BOSCH

Vauxhall Astra GT/E

& 1.81 83 to 86; Belmont

LE/LE2 JETRONIC

1.8i 84 to 86; Cavalier 1800 82 to 86

Airflow sensor

MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve Injectors Thermotime switch ECU (in RH footwell) Water temperature sensor AaANRWH™ OANA 70 Air temperature sensor 771 Pressure regulator 72 Relays 13 Cold start injector 714 Warm-up regulator 75

Vacuum/pressure

16 17 78 19 20

Fuel filter Metering head Injector resistors Load enrichment device Additional idle control valve

switch

Not all items fitted to all models

H.19149

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

Ensure that the engine is at normal operating temperature, and run it for approximately twenty seconds before adjusting the idle speed. Locate the bypass adjuster ‘1’ on the throttle body, and slacken the locknut. Screw in the adjuster to decrease the idle speed, and unscrew the adjuster to increase the speed. Re-tighten the locknut.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

114

Vauxhall

BOSCH

LE/LE2 JETRONIC

Refer also to page 39

Carlton 2000i 83 to 85; Carlton 2.21 84 to 86

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)...........

COsstidia (26) . Sart.

850 to 900 M 775 to 825 M (2.21)

Injectors (OhMS) o.d. gees i S520 Cold start injector (ohms) .......

N/A

G7o.t0 725 Al (2.2))

Auxiliary air valve (ohms)........

50

0.5 max

Water temperature sensor:

COvat BOO0Q, roi (MG )ecccrrse

20

Pas

Snap open throttle........

‘Toe

Airflow meter/MAP sensor

Saas a

Senet

Fuel system checks

aaa a

Fuel pressure - regulator vacuum pipe

disconnected - bar (Ibf/in2) ..............

2.5 (36) nominal

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

ohms

W & Switch body

—_

Test terminals

ohms

5&7

250 to 1300

8&5

300 to 400

Volvo

BOSCH

LE/LE2 JETRONIC

360 GLEi & GLT 83 to 89

Airflow sensor MAP sensor Throttle position switch/sensor

Auxiliary air valve /dle speed contro! valve Injectors Thermotime switch ECU (under facia) Water temperature sensor ARWBH™ DANA 70 Air temperature sensor 77 Pressure regulator 72 Relays 13 Cold start injector 14 Warm-up regulator 75

Vacuum/pressure

76 17 78 19 20

Fuel filter Metering head Injector resistors Load enrichment device Additional idle contro! valve

switch

Not all items fitted to all mode!s

H.19039

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

_ Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

Bosch

LE/LE2 Jetronic

Contents

Injection signal and duration ..........eeeeeeeee mnrottie butterfly setting seat trees Boschuthrottie: DOSItlOM: SWC hers sccte cette once FRUIT AR Veal VAIN Cenc dhicascentenestgrquant ean Ate ate ceaR

eer Peto donere boat bd cciane ieee amen ae fet ere ° 5s Water heated auxiliary air Valve .............ccccccceeeee eee be Automatic idle’speed COntrOli..cc.sercsersest eae Cheer, . o 8 MOLOLe DVHASS ICIESERUIG) cncecstccnrccospanartmeesas Mo. Airflow meter and air temperature sensor

........

Injection signal and duration General Wherever possible, it is advantageous to check for an injection signal and the duration as a first test. In many cases, this will provide a good indication of possible faults

H. 2/200 Injection waveform in the electrical/electronic operation of the system. Refer to Chapter 2 for instructions on how to check for injection signal and duration.

118 118 118 419 119 120 ae 12g

Water temperature SENSOP ...f0. fence snupseee-scgervencladecsecs cee PY COCO he becnsscinsahacvnen ae ch he eee cn kes Fuel system pressure and fuel pump checks .........cccccceceeeeeees Cold start injector and thermotime SWitCh ...........ccccccccceeseceeees Relay Checks... BU Petoadconsteseaes ies Raaa ee Lier CharSWILCTN saretatec Baiccutoht te hte e aera eee eee ee een meer ea ECU

checks, fault diagnosis and wiring diagrams

check the operation of the ignition system first. The injection system relies on a signal from the ignition system, and will therefore not function if the ECU does not receive an ignition pulse. Check for an injection signal. If there is no signal available at all, refer to the injector checks. If an injection pulse is available, check the duration. If the engine is cold, and the pulse is too small, or if the engine is hot, and the pulse is too large, refer to the water temperature sensor checks. Also refer to the airflow meter checks. If the engine does run, again check the duration cold and hot, and if it is incorrect, refer to the checks as detailed above. If the engine is already hot, refer to the water temperature sensor checks for details of the water temperature simulation test. Check for an increase in the duration during a snap acceleration test, and if it is not acceptable, refer to the airflow meter checks. Also check for injection cut-off during deceleration (where used), and if it is not functioning, check the throttle position sensor. If the above checks appear to provide acceptable results, this generally indicates that the electrical system is satisfactory. If there still appears to be an injection system fault, carry out the fuel pressure checks before any detailed electrical component checks are carried out.

Dynamic checks

Throttle butterfly setting

To obtain an injection signal (unless the test equipment is supplied with an adapter), it is usually easiest to roll back the rubber protection boot on one of the injectors, and touch the test lead to each of the two terminals separately until a signal is obtained. Alternatively, gain access to the ECU terminals with the multi-plug still connected, and refer to the wiring diagram for the

The throttle linkage and throttle butterfly are factory-set, and should not normally be adjusted. If it is necessary to check or adjust the butterfly closed position, the following procedure can be used. Slacken off the throttle linkage stop screw on the throttle body until there is a small air gap. Screw the stop screw in an additional half-turn. This should result in an air gap of approximately 0.05 to 0.15 mm (0.002 to 0.006 in) between the throttle butterfly and

appropriate

terminals

to

connect

to,

to

obtain the injection signal. On an engine which will not start, always

122 123 123 125 126 126

H.21205

Throttle butterfly air gap (typical) the throttle casing. On vehicles that do not have an automatic idle speed control, with the idle bypass screw fully closed, the idle speed will typically be around 600 to 650 rpm with the correct butterfly air gap. After setting the butterfly, check the operation of the throttle position switch or sensor.

Bosch throttle position switch General description The throttle position switch indicates to the ECU idle and full-load positions, via two sets of contacts in the switch body. When neither of the two switched positions is indicated, a part-load condition is assumed. Mixture strength is dependent on the switch position, and automatic idle speed control. valve operation (where fitted) and deceleration fuel cut-off are implemented when the idle position is indicated.

Static checks Either during cranking or with the engine running, check for battery voltage to the centre wire of the connector plug (switch terminal 18) either by disconnecting the plug from the switch, or by rolling back the rubber protection boot. The supply voltage originates from the control or system relay

Bosch

Auxiliary air valve General description The auxiliary air valve provides a fast idle when the engine is cold, and during the initial warm-up period. As the engine warms up, the valve progressively closes, reducing the idle speed to normal. The valve remains open (fast idle) until a combination of engine heat and electrical heating force it to close.

Dynamic checks

H.21202

H.21203

Engine cold Where possible, clamp shut one of the two air hoses* connecting the air valve to the induction system. If the valve is functioning, the idle speed will drop. If there is no drop in the idle speed, this indicates faulty valve operation. Engine warm Where possible, clamp shut one of the two air hoses* connecting the air valve to the induction system. If the idle speed drops, it indicates faulty valve operation. If there is no drop in idle speed, this indicates correct valve operation. *Note: /f it is difficult to clamp an air hose for either of the above tests, one of the hoses should be disconnected, and both openings blanked off. Restart the engine, and note whether the speed is the same or reduced. The same conclusions can be drawn as for tests with the hoses clamped.

Note: 7he throttle butterfly adjustment should be correctly set before adjusting the idle position switch. ;

Check for continuity between the switch centre terminal and terminal 3 with the throttle fully open. If there is no continuity, renew the switch. Check that the full-load contacts are open when the throttle is closed.

benefit from cleaning with a_ suitable solvent. If a valve still remains closed after cleaning, it will probably need renewing. When a valve remains open, it may be caused either by a broken heater element, or by a faulty electrical circuit to the heating element. With the plug disconnected, check for the specified element resistance by measuring across the valve terminals. If the reading indicates a short- or open-circuit, renew the valve. With the plug disconnected, check for battery voltage (engine running or cranking) at one of the plug terminals. The voltage supply originates from the control or system relay (refer to the wiring diagram). If there is no voltage supply at the relay, carry out relay checks. With the ignition off, check for a good earth connection to the remaining terminal on the connector plug. An alternative test can be carried out by independently supplying battery voltage and an earth connection to the valve terminals. The valve should completely close within three to four minutes. If the valve does not close, cleaning with a suitable

solvent may

effect a cure,

otherwise

the

valve should be renewed.

Water heated auxiliary air valve General description The valve operates in much the same way as the electrically heated type, but it relies on coolant water temperature to close the valve. A wax capsule is normally built into the valve assembly, which when _ heated, expands and closes off the air valve.

Throttle position switch and terminals

(refer to the system wiring diagram). The remaining two terminals are connected to the ECU — terminal 2 for idle position, and terminal 3 for full-load position. With the plug disconnected and the throttle closed, check for continuity between the centre terminal and terminal 2 of the switch. If it is open-circuit, slacken the securing screws, and rotate the switch until continuity exists. If there is still no continuity, renew the switch. Check that the idle contacts open when the throttle is opened.

119

LE/LE2 Jetronic

Dynamic checks Engine cold Start the engine and squeeze closed one of the two air hoses connected to the auxiliary air valve. The idle speed should drop, indicating that the valve is correctly open. If the idle speed is not affected, it is likely that the auxiliary air valve is faulty. Auxiliary air valve

Static checks Disconnect the two air hoses from the valve body, and examine the opening of the valve port, either by using a mirror if necessary, or by removing the valve from the engine. The valve should be open if the engine is cold, and closed if the engine has been running for more than five minutes. A valve that has stuck open or closed may

Engine warm With the engine running, and at normal operating temperature, squeeze closed one of the air hoses. If the idle speed does not alter, it indicates correct operation. If the idle speed drops, the valve is likely to be faulty.

Static checks The valve operation checks may be carried out with the valve removed and placed in cold and hot water, in much the same way as a thermostat is tested. Look for an open and closed valve port respectively.

120

Bosch

LE/LE2 Jetronic

/ PARTIALLY OPEN

H. 21232

Auto idle speed control valve

H.212/4

CLOSED Auxiliary air valve ports

Automatic

idle speed control

General description The idle speed control is a computercontrolled air by-pass valve, which carries out idle speed stabilisation requirements, particularly fast idle for the engine when cold and during warm-up. The valve also compensates for changes in load on the engine when it is idling, for example, when air conditioning is switched on. An independent ECU controls the valve opening by varying the electrical signal. There are two signals which switch the earth circuits for the valve, one to open and one to close the valve, and a single voltage supply to the centre terminal of the valve plug.

Dynamic checks Note: Before carrying out the following checks, ensure that the throttle position switch is correctly adjusted. If it is suspected that the idle speed control valve is not functioning, roll back the rubber protection

boot on the control valve

plug, but leave the plug connected. Run the engine, and connect the test lead from either

a dwell meter or an oscilloscope that can also indicate dwell to each of the outside terminals on the plug. Check for a waveform or dwell reading at

each terminal. Note that the waveforms and readings should differ (refer to the illustration). The dwell readings relate to the width of each pulse on the waveform. A dwell reading or waveform indicates that the ECU is attempting to control the valve. The ECU should then alter the signal when changes in load occur, or if the engine is very cold. The exact dwell reading at idle, with no load, will depend on the temperature, but it will also depend on the throttle butterfly and bypass idle adjuster settings (refer to ‘throttle bypass idle setting’). If there is no waveform or dwell reading available, carry out the static checks. If a dwell reading or waveform is available from both terminals, with the engine idling, switch on electrical ‘consumers’, for example headlights or heated rear window. The idle speed may initially drop, but it should be restored to original speed almost immediately. Note that the dwell reading or pulse width on the waveform will increase or decrease, depending on which terminal the test equipment is connected to. For subsequent checks, leave the test lead connected to the terminal which provided the smaller reading, or the reading which increased when electrical load was applied. Refer to the Specifications for the correct dwell readings. If there are no readings quoted, use the typical values in this chart (engine warm, no electrical load):

Engine type % degrees 4-cyl 30 27 6-cyl 30 18 Apply an electrical load, and the readings should increase by 3 to 4% or more, and the degree values will increase proportionally. If the dwell readings are incorrect, or they do not alter, refer to the static checks, and ensure that the idle control valve is not seized. Also refer to the throttle bypass setting procedure. If the dwell readings are incorrect, but do alter, refer to the throttle bypass setting procedure.

H.21233 DWELL PERIOD

Auto idle speed waveform

Static checks Roll back the rubber protection boot on the control valve plug, and with the engine running, check for battery voltage to the centre wire. If there is no voltage, trace the wiring through to the control valve ECU terminal 4. Disconnect the plug from the valve, and check the resistance between the centre terminal on the valve and each of the outside terminals. Compare the readings with those specified, but note that a fault will usually be indicated by an open-circuit. Also check

121 Bosch

that there is no continuity between any of the terminals and the casing. Disconnect the air pipes from the valve, and check that the valve is free to move. It is possible to supply an independent live feed to the centre terminal, and an earth to each of the side terminals in turn to check that the valve functions, but do not leave the valve connected for more than one second. If the valve appears to be seized, cleaning with a suitable solvent may effect a cure, but if not, the valve should be renewed. With the plug disconnected from the valve, check for continuity from the two outside wires to terminals 3 and 5 of the control valve ECU. Disconnect the plug from the ECU when carrying out the test. Check for continuity from the ECU plug terminal 2 to earth. With the engine running, check for battery voltage to ECU plug terminal 1. Note that the supply originates from the control relay terminal 87b. Check that there is a normal ignition dwell or primary ignition waveform to terminal 12 of the ECU plug, and if not, check the wiring through to ignition coil terminal 1. Continuity checks should also be made between ECU plug terminal 8 and terminal 2 of the throttle switch, and between ECU plug terminal 9 and one of the temperature

sensor plug terminals. If all the electrical checks are correct, and the control valve checks do not indicate a fault, check the water temperature sensor, and if satisfactory, suspect the control valve EGU

Throttle bypass idle setting Note: 7his procedure only applies to vehicles with an automatic idle speed contro/ valve. If the bypass idle adjuster is screwed to the closed position, the automatic idle speed control valve will open as far as possible, in an attempt to maintain the idle speed. When additional load is applied to the engine, the valve may not be able to open any further to maintain the idle speed. Check that the throttle butterfly and throttle switch are correctly adjusted. Refer to the automatic idle speed control dynamic checks, and cannect a dwell meter or oscilloscope to the two outside terminals of the control valve plug. Keep the test lead

connected to the terminal that provided the smaller dwell reading, and screw in the bypass idle adjuster. The dwell reading should increase as the idle control valve is opened by the ECU. If the reading decreases, connect the test lead to the other terminal.

LE/LE2 Jetronic

Adjust the bypass screw so that the dwell reading is as specified. If the specification is not quoted, set the bypass adjuster so that a reading of around 30% (27 degrees for a four-cylinder engine, or 18 degrees for a six-cylinder engine) is measured. Note that when the throttle butterfly and bypass idle adjuster are set correctly, the idle speed will usually be around 100 rpm less than specified when one of the air pipes to the control valve is blocked. lf the idle is unstable, refer to the automatic idle speed control checks.

A delay in the increase, or no increase at all, usually indicates a sticking flap in the airflow meter. In most cases, this can be cured by cleaning. An erratic change in voltage, or hash on the oscilloscope trace, often indicates a fault in the resistance track, and this is not normally serviceable. Also check for a voltage increase when the throttle is snapped open.

Air flow meter and air temperature sensor

General description The airflow meter indicates to the ECU the changes in airflow to the engine. Incorporated into the airflow meter is the air temperature sensor, for fine-tuning of the mixture strength.

AH 2/20/

Dynamic checks

Airflow

An indication of poor airflow meter response can be obtained by checking the injection duration. Note the duration at 2000 rpm, and again during snap _ acceleration. If there is no substantial increase in duration,

it usually

indicates

an

airflow

meter fault. Alternatively, gain access to the airflow meter flap by removing the assembly from the air filter casing. With the electrical connector plug and_ remaining intake trunking still connected, run the engine at around 1200 rpm, and note the injection duration, or the exhaust gas CO reading. Slowly push open the airflow meter flap, which will simulate an increase in airflow (also check for a sticking flap). The injection duration and CO level should increase, and it is likely that the engine will attempt to stall due to flooding. If the increase in readings does not occur, or if the flap is sticking, continue with the following checks. Preferably using the low-voltage facility of an oscilloscope or a digital voltmeter, check the output voltage from the airflow meter on terminal 7. To gain access to the terminal, roll back the rubber protection boot from the airflow meter connector, and locate the wire corresponding to terminal 7. With the connector in place, crank, or where possible run, the engine. Connect the oscilloscope or volt test lead to the exposed terminal connection, and note the voltage. With the engine running, slowly open the throttle, and note the progressive increase in voltage.

Condition Cranking (throttle closed) Normal idle Fast idle 3000 rpm Snap open throttle

meter

Typical voltage (V) 1.5 to 3 (approx) 45to5 ‘eis jyf6)e 2) 6 to 7 Up to 8

If there is no voltage reading, or if the voltage change is erratic, refer to the static checks Section. Connect the test lead to pin 8, and note the voltage reading with the engine cranking or running. A typical reading is approximately 7 to 10 volts, depending on the ambient air temperature. If the reading is incorrect refer to the static checks Section.

Static checks Disconnect the connector plug from the airflow sensor, and check the resistances across the airflow meter plug terminals, comparing them with those specified. A reasonable tolerance is indicated by the specified values, but a fault is usually indicated by an open- or short-circuit. When checking between terminals 9 and 7, gain access to the airflow meter flap by removing the assembly from the air filter casing, and slowly push the flap open to its limit. The resistance reading should increase and decrease in a series of steps. A fault will normally be indicated by an open-circuit at

122

Bosch

some stage during the flap movement.

LE/LE2 Jetronic

engine warms up. If the engine will not start, the duration can be checked during cranking, but note that the first few moments may

Also

check for mechanical resistance as the flap is

moved, especially near the closed position. A sticky flap can often be cured by cleaning, but if not, the assembly should be renewed. The

air

temperature

sensor

provide

resistance

reading between terminals 8 and 9 will depend on the ambient air temperature. If a resistance reading within the highest and lowest specified values is obtained, it Is unlikely

that

a

fault

exists.

Checks

hot,

When carrying out the dynamic checks, if there is a zero-volt reading, carry out all the static checks, but also check for supply voltage to terminal 9 on the airflow meter connector with the engine cranking or running. The supply voltage originates from the control or system relay (refer to the wiring diagram). Also check for continuity of the wiring from connector plug terminals 6, 7, 8 and 9 to the corresponding pins on the ECU (refer to the wiring diagram). Note:

F/ectrica/ faults in the airflow meter

are not normally serviceable.

duration

reading

than

fault,

a probable

but

sensor

or sensor

refer to the water

tem-

perature simulation test.

however, be carried out by warming or cooling the air temperature sensor” and noting the resistance changes. to

higher

indicates

circuit

can,

*“Warning: Do not use a naked flame warm the air temperature sensor.

a

specified. During cranking or running, a substantially smaller than specified duration when cold, or a substantially larger duration when

AH 2/2/15

Static checks Airflow

meter

Water temperature

terminals

sensor

General description The water temperature sensor provides a varying voltage signal to the ECU to indicate engine. coolant temperature. This enables mixture correction to take place in response to engine temperature changes.

Dynamic checks Carry out an injection duration check, and refer to the specified readings. Checking the duration on a cold engine should provide a large duration, which should reduce as the

Pull off the sensor connector plug, and measure the resistance across the sensor terminals, comparing the readings with those specified. If the sensor is not removed from the engine, it is advisable to take measurements with the engine cold, and then with it hot, to establish the change in resistance in conjunction with the change in temperature.

The

sensor

can,

however,

be

removed and tested in water at various temperatures. If the sensor resistances are correct, check the connections and the continuity of the wiring from the two sensor plug terminals to the ECU and earth (refer to the wiring diagram).

Water temperature simulation test With the engine switched off, pull off the connector plug from the water temperature sensor, and bridge the connector plug terminals with a suitable piece of wire, or preferably, a resistor of approximately 200 to 300 ohms. This will provide a hot-engine simulation. Crank, and if possible, start the

AH. 2/203

H. 2/204.

Moving airflow meter flap

Water temperature sensor Plug terminal is blue or white

Bosch

engine

(run at 1500

rpm), and

note the

injection duration, which should be close to the specified reading for a warm engine. Switch the ignition off, and remove the bridging wire or resistor. Either leave the plug terminals unconnected, or preferably, bridge with a resistor of approximately 6 Kohms or more, to simulate a cold engine. (This simulation can cause extreme flooding of the engine, preventing starting.) Repeat the test, which should now provide a noticeably larger duration than for the hot-engine simulation. The duration reading should be close to, or greater than, the specified value for a cold engine. If the engine fails to start due to flooding, this indicates correct ECU response. If, during the simulation tests, there is no noticeable difference in the duration measurements, check the sensor plug and wiring for continuity to the ECU terminal and to earth (refer to the wiring diagram). If there is no wiring fault, suspect the ECU.

T2z3

LE/LE2 Jetronic

duration appears to be incorrect, or if the supply voltage is correct and there is still no injection signal, refer to the ECU checks Section for a guide to further tests.

to

protect

against

a

possible

short-

circuit.

Static checks Remove the plug from the injector(s), and check the resistance across the two injector terminals, comparing with the reading specified. Also ensure that there is no continuity between the injector body and the injector terminals.

H 21207

Bridging a relay with a 20A fuse

Injectors General description

Fuel system pressure checks

The injectors receive a common live feed from the control relay, and are switched on and off.on the earth circuit, through the ECU. On six-cylinder engines, the injectors

The system should provide fuel in the fuel rail and injectors, at a pressure which is constant in relation to manifold pressure. The system consists of a pump, main filter, fuel rail (to distribute the fuel to the injectors) and injectors, which contain a fine filter. To maintain the pressure, a pressure regulator is fitted, which allows excess fuel back to the tank. The regulator is connected to the inlet manifold via a vacuum pipe, in order to adjust the fuel pressure in conjunction with changes in the manifold pressure.

are switched in two groups of three.

Dynamic checks

AH. 21202

Crank or run the engine, and listen to each injector for a clicking sound as the injector operates (it may be necessary to use a suitable listening device, such as a screwdriver, as a ‘stethoscope’). lf it appears that an injector is not functioning, carry out the static check. If the static check results are acceptable, check for continuity of the wiring between the injector plugs and the ECU multi-plug — disconnect all connector plugs for this test, and refer to the wiring diagram. If a// the injectors (four-cylinder engines), or all the injectors of one or both groups (six-cylinder engines), are not functioning, carry out the following checks. Check the injection signal and duration, and if correct, carry out the static injector check. If there is no injection signal, crank the engine and check for a supply voltage to the injector plugs from the control relay (refer to the wiring diagram), and carry out relay checks if necessary. Check for continuity of the wiring from

the injector plugs to the ECU

bridging wire should be fitted with a 20 amp fuse,

multi-plug

connector — disconnect all other system connector plugs and refer to the wiring diagram. If the injection signal exists, but the

Connection to an injector

Note: /f there is no fault found during the above checks, but it is apparent that one or more injectors are not functioning correctly, it is possible that fouling exists in the faulty injectors, and a flow rate test may be required — refer to Chapter 2.

Fuel system pressure pump checks

and

fuel

Fuel pump relay — bypassing For a number of the following tests, it is necessary to crank the engine in order to allow the pump to run. It is possible to bypass the pump relay, which will allow the pump to run without cranking. Locate the control relay, which also acts as the pump relay. Remove the relay and bridge the connectors on the relay holder which correspond to terminal 30 (battery positive) and 87b (pump supply). The

Warning: Before disconnecting any of the fuel lines, it is advisable to disable the fuel pump and run the engine to depressurise the fuel system. The fuel pump relay is incorporated in the control relay, preventing the pump supply from being disconnected without disabling the rest of the injection system. /t is therefore necessary to independently disconnect the fuel pump electrical connections directly at the pump. Disable the fuel pump, and run the engine until it stops — this will depressurise the fuel system. Locate the fuel supply line to the fuel rail, and disconnect the supply line. Connect the fuel pressure gauge as indicated in equipment manufacturer's instructions. Wherever possible, locate a tap between the gauge and the fuel rail. Reconnect the fuel pump, and start the engine (make sure that if a tap is fitted with the gauge, it is in the ‘open’ position).

124

Bosch

If the

engine

will

not

start,

crank

the

engine, or bypass the relay, which will allow the pump to operate and provide the required pressure.

Note vacuum

the fuel

pressure.

pipe connecting

Disconnect the fuel

the

pressure

regulator to the inlet manifold, and plug the hole to the manifold. The fuel pressure should increase to the specified value,

(during cranking the engine only produces a low vacuum level, and therefore the fuel pressure will be very close to the specified level, even if the vacuum pipe remains connected). Also

note

that with

the engine

running,

the same test can be carried out using a CO reading, which should increase in conjunction with the fuel pressure increases. Note: /t is common for the system pressure to be correct when the engine is running under workshop test conditions. Unless the pressure can be checked with the vehicle on a rolling road, it will be necessary to carry out fuel pump checks, to establish whether the pump can supply sufficient fuel at the required pressure when the fuel demand is high. With

the

engine

running,

if the

fuel

LE/LE2

Jetronic

pressure was already at the specified level before the regulator vacuum pipe was disconnected, and the pressure remains at this level, the pressure regulator is likely to be faulty, but first ensure that manifold vacuum Is available from the vacuum pipe. If the fuel pressure is higher than specified, it indicates a faulty pressure regulator, but it is possible for a blockage on the return line from the regulator to cause a high system pressure. Attach an independent pipe to the pressure regulator on the return pipe connection, run the engine and allow the fuel to drain into a suitable container. If the fuel pressure is now at the specified level, check the vehicle return line for a blockage. If the pressure is still high, renew the regulator. If the fuel pressure is lower than specified, it is possible that the regulator is faulty, but the most likely cause is a faulty fuel pump, or a severe blockage in the fuel filter or supply line. Where possible, with the engine running or cranking, briefly clamp the fuel return line from the regulator. If the pressure now rises substantially, it indicates a regulator fault. If the pressure remains low, carry out the fuel pump checks, and also look for a fuel leak between the pump and the regulator.

PRESSURE REGULATOR FUEL RAIL

EXCESS FUEL RETURN

INJECTOR

Fuel pump and filter checks The fuel pump is able to provide the system with a greater quantity of fuel than is required to run the engine. The excess fuel is passed back to the tank via the fuel pressure regulator. The fuel passes from the pump through a main filter before reaching the fuel rail and injectors. The electrical supply for the pump originates at the control relay, and when the ignition is initially switched on, the relay should run the pump for approximately one second. The relay will then cut off the pump until an engine speed or crank signal is supplied to the relay. Switch on the ignition, and listen for pump operation — it should run for approximately one second. If the pump is not running, check for battery voltage at one of the connections at the pump by repeating the ‘ignition on’ test, or by cranking the engine. If the supply voltage is not available, check the wiring through to the control relay (refer to the wiring diagram), and carry out relay checks if necessary. Check for a good earth on the remaining connection at the pump, and rectify if necessary. If the electrical connections and supply voltage are good, but the pump will not run, it should be renewed. When carrying out system pressure checks, if the pressure was low, or if it is suspected that the pump is failing when the fuel demand is high, it will be necessary to carry out a flow rate and maximum-pressure check. If a pressure gauge and tap can be connected to the system (refer to the first fuel system pressure check), turn the tap to the ‘off’ position, and crank the engine until a maximum pressure reading is reached. The pressure should reach approximately 85 Ibf/in? or more. If the pressure is too low, it indicates a pump fault. It is unlikely that a ~ filter blockage will prevent the pressure from reaching the required level, unless the blockage is very severe. If the maximum

FUEL TANK FUEL PUMP

pressure

is acceptable,

it

is still advisable to carry out a flow rate check. Disconnect the fuel supply line from the fuel rail, and allow the fuel to drain into a suitable container. The test should ideally be carried out for a period of at least thirty seconds. It would therefore be advisable to bypass the fuel pump relay to allow the pump to run without cranking the engine (refer to ‘fuel pump relay — bypassing’). Run the pump, and note the fuel quantity delivered, comparing with the specified value. A low output would indicate a probable pump fault, but a check should be made for blockages in the lines and the filter,

Fuel system

as detailed in the following paragraph.

Bosch

LE/LE2

125

Jetronic

LIVE ONLY DURING CRANKING

H.2/209

-FUEL RAIL

COLD START INJECTOR

BUELSSUPPLY

>

Disconnect the fuel supply line from the filter, and repeat the fuel flow rate test by running the fuel directly from the pump to the container. If the flow rate is now close to that specified, the filter should be renewed. If the flow rate is still too low, renew the pump The fuel pump assembly contains a nonreturn valve, to maintain pressure in the system after the pump is switched off. A faulty valve will normally not have a great effect on engine performance, except for creating a slight delay in starting. This will be more noticeable on a hot engine. Check the valve by connecting a pressure gauge to the system (refer to the first system pressure check). Run the engine briefly with the regulator vacuum pipe connected. Switch off the engine, and note any loss in pressure over a period of two minutes. The pressure’ will fall slightly, but should not drop by more than 0.6 bar (8 Ibf/in?) approximately from the running pressure. If the pressure loss is too high, repeat the test, but clamp the supply line from the pump as the engine is switched off. If the pressure loss is now acceptable, renew the pump assembly, or just the non-return valve if possible.

Connecting

a pressure gauge

Cold start injector and thermotime switch General description

——

H.21Z10

The cold start injector is used during cranking only, to aid the initial starting phase. During cranking, the cold start injector is switched on by a thermotime switch (located in the cooling system). The thermotime switch will allow the injector to operate when the water temperature is below a predetermined value. During cranking, voltage is also supplied to a heating element in the switch, causing the switch to break the cold start injector earth circuit. The thermotime switch can switch off the injector almost immediately, or after as long as eight to twelve seconds, depending on the initial water temperature. Note: 7he predetermined temperature, and the maximum time taken for the heater to open the contacts, are stamped on the thermotime switch body. H.21212

Static Checks

a dP

AH.2/204

Pressure regulator

Prevent the engine starting by using the engine-kill’ facility on the test equipment, or by disabling the fuel pump (refer to the fuel system pressure and pump checks). Ensure that the water temperature is below the predetermined level — if necessary, remove the thermotime switch and place it in cold water. Disconnect the plug from the cold start injector, and crank the engine. Check for battery voltage to one of the two terminals on the plug. If there is no voltage, check through the wiring back to the starter circuit. Disconnect the thermotime switch plug, and check for continuity between the live terminal on the injector plug and one of the

Cold start injector two terminals on the thermotime switch plug. Also check for continuity on the remaining injector plug terminal to the remaining thermotime switch terminal. Rectify as necessary. With the plug still disconnected, check the specified resistance across the two injector terminals. A short- or open-circuit indicates a faulty injector.

126

Bosch

LE/LE2

Jetronic

a

Examine the plastic top of the thermotime switch with the plug disconnected. There should be letters corresponding to the two terminals, typically, ‘G’ and ‘K’ or ‘W’. Check the resistance between ‘K’ or ‘W’ and earth. The reading should be zero ohms if the

value stamped on the switch body. Immediately disconnect the switch plug, and check the resistance between the switch terminal ‘K’ or ‘W’ and earth. There should now be an open-circuit reading. If the switch remains closed (zero ohms), renew

temperature

It.

is

below

the

predetermined

available voltage. If the voltage is now available, it is likely that the relay is at fault, but check

the relay source.

holder

for

connections

continuity

to

General description An inertia switch is fitted on some vehicles, which will cut off the electrical supply to the fuel pump, and possibly other components, in the event of an accident.

Static checks If it is apparent that there is no live feed to the pump or other components, locate the inertia switch, and check for continuity between the two terminals. If the switch is open (no continuity), operate the reset button. If the switch is still open, renew it.

Relay checks General description The relay is used to provide a switched supply voltage to the injection system and fuel pump. The relay requires certain items of electrical information before it will switch on the system components.

Static Checks Note: Refer to the wiring diagram carrying out the following checks.

when

If during any system component checks, it is found that there is no supply voltage available from the relay, check for continuity from the component to the relay terminal 87, and rectify if necessary. Remove the relay from the holder, and bridge the relay holder connections corresponding to relay terminals 30 (battery positive) and 87 (output to the injection system). Refer to the wiring diagram, and note whether all the components supplied with voltage from terminal 87 now have-

H. 212/3

Thermotime switch Plug terminal is brown

H.2/216 Typical inertia switch

(=[=[=[=1=1=1=1= [else TST (=T=[=T=T=1 ai920 ae - waaiseuels=] 2S 1

2

14

3

4

16

5

17

6

7

8

8

ECU

terminals

S

10

Tipe

to

their

Inertia switch

Remove the injector from the intake manifold, and connect all fuel and electrical connections. Crank the engine (ensure that the temperature is below the predetermined level) and check for a wide conical spray pattern. A poor pattern would indicate the need for injector cleaning or renewal. No injection at all would indicate a faulty injector, but first check for acceptable fuel pressure.

value. If the temperature is above the predetermined value, there should be an open-circuit or infinity reading. If readings are incorrect, replace the thermotime switch. Test the heating element by checking for a resistance between ‘G’ and earth. The exact reading will depend on the type of switch fitted, but if a zero ohm or open-circuit reading is obtained, renew the switch. Carry out the remaining checks detailed below. Ensure that the temperature is below the predetermined level, reconnect the plug, and crank the engine. The engine should be cranked for a period equivalent to the time

all the remaining

2

13

ECU

checks — Bosch

LE/LE2 Jetronic

General It is not possible, without dedicated test equipment, to carry out a direct check on the ECU. It is, however, possible to establish whether or not the ECU is functioning by carrying out the following tests. The tests are divided into two categories — one with the ECU multi-plug connected, and one with the multi-plug disconnected. It should be possible with these tests to establish that all the

ECU multi-plug terminal

Multi-plug connected (Yes/No)

1 4 5 10

Yes Yes Yes Yes

12

Yes

24

Yes

Z 3 5 7 8 13 25 6 and 11

No No No No No No No _

connections to the system components are satisfactory, and that all the relevant signals are being passed from the sensors to the ECU. If the ECU is still not providing the correct output signals to the injectors, then the ECU should be substituted. Warning: Do not disconnect the ECU multi-plug with the ignition switched on.

Test to be carried out

Check for primary ignition signal during cranking, or when running ~ Check for battery voltage from starter circuit during cranking, or when running Check for battery voltage from relay terminal 87 during cranking, or when running Check voltage to water temperature sensor during cranking, or when running (voltage depends on temperature) Check for injection signal for all four fuel injectors, or one group of three (6-cyl), during cranking, or when running Check for injection signal for one group of three fuel injectors (6-cyl) during cranking, or when running

Check connection Check connection Earth connection Check connection Check connection Earth connection Earth connection Not used

to throttle switch to throttle switch — also check connection to airflow meter terminal 5 to airflow meter terminal 7 to airflow meter terminal 8 (6-cyl)

signals or Carry out tests on terminals 1, 4, 5, 9,13 and 25 — if acceptable, but there are no injection outputs to sensors, suspect the ECU

128

Fault diagnosis — Bosch

LE/LE2 Jetronic

Test components in the order given alongside specific faults

55

0 ay

Grew >

=

”

>

TC

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ge]

z©

OR 5 c

“e

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End

pO) 5. 0 Rae

S70©

oss

©

”

—

om

=

Ou SS

resCatug2

eoS >

ites be Se afe)hae a ie) Coc s

oS

5 > roy hh

6

tas. S po

tiasdGE Ci5 ts Coeig

ats

5

x

{ro

ks

Ne

Vito:

“ye SS

®

>

=

c

3

n

c er5 ecm

On

srefnqivits

re rmoe

Oba

2

4

i

®

S

regulator Fuel pressure

..............

7

6

8

..........:c:esee

7

6

2

ih

6

2

case cece dence canes nce

7

Z

6

=

fay

KR OO ©

........:.ccsceeeseeeeees

7

2

6

3

5:

A

Poor cold starting Poor hot starting

..............00:06

IGG TOO AS ia cata egg nee idle:too slow...

Excessive fuel CONSUMIDPTION

i=

Bee.

(ee

Unstable idle

ne

te = OS

= Fe)) =

acceleratiOn

Oo

ones

=o

Flat spot under

—

‘2

© 5

LOSS. OF POWEF

~ =

oO

9 @ § meee

°

Engine will not start

iS (eo)

ee

5

............ccccceeeeeeees

4 on

7

2

6)

High CO at idle (adjuster — INGTTOCTIVE) 35... crareet ee

7

5:

ei

Low CO at idle (adjuster INOFFECLIVE) pecaas ened er nnnraneste

7

Ee

Za

ne ee G.5e-

D

2

1

2

7

vs

7

3

7

6

6

4

7

ei

switch thermotime and injector Cold start AN_ N

Bosch

SO],

15

Wil

eh

50|

87B

129

LE/LE2 Jetronic

87 0

Live feed to terminal 9 airflow meter, injectors, throttle switch, ECU

©

Live to fuel pump

QO

Live when

9

Earth connection

(fused 20 amp)

cranking

(starter motor)

S Terminal 1 coil (primary signal) 8

Live ignition on

S Battery +ve

H. 21221

Relay wiring diagram

Injection ECU

O

Water temperature sensor

Throttle switch

Airflow meter \

Bosch

LE/LE2 Jetronic wiring diagram

H.21222

Earth connection

130

Bosch LE/LE2 Jetronic

Injection ECU

Fi

Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4

Cylinder 5

©

Terminal 50 Fuel injection relay

©

Terminal 87 Fuel injection relay

Cylinder 6

Note: Injectors on 4-cylinder models all connect to terminal 12. Injectors on 6 and 12- cylinder models divide into two groups

H. 2/223

Bosch

LE/LE2 Jetronic wiring diagram

Injection

ECU

©

Terminal 87B Injection relay Earth connection

Terminal 1 Coil ©

Water temperature sensor Terminal 2 Throttle switch

Uy == 5)

Auxiliary air valve

Ge SP

Idle speed control valve

ee 2p

Idle speed control

©

2

Os Cha 0

unit

Idle speed control unit and valve fitted to Vauxhall/Opel engine codes 25/30E

Bosch

LE/LE2 Jetronic wiring diagram

H. 21224

Idle speed check connector

131

Bosch LE/LE2 Jetronic

Injection ECU

Earth connection through body

Thermo

time switch

Cold start injector

Only used on early systems,

Bosch

H.2/225

LE/LE2 Jetronic wiring diagram

132

Refer also to page 39

LE3 JETRONIC

BOSCH

Citroen BX 19 TRi & GTi 86 to 89

SPECIFICATIONS M = Manual

N = Non-adjustable

AT = Auto

N/A = Not available/applicable

+ = Throttle open

* = Throttle closed

Dynamic checks

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

800 to 850 M

Injectors (ohms)

15 to 20

Cold start injector (ohms) Auxiliary air valve (ohms) CO at idle (%)

Water temperature sensor: (between terminals)

[Ca 10

lee) (50)

20 (68) 80 (176) CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

°Ci

(°F)

Airflow

20

(68)

(Pins 1 & 4 in

Injection duration checks

O (32)

meter)

Refer to Chapter 2

Injection waveform

4. 2/200

_—‘{Test terminals

Throttle position switch/sensor

|Test terminals

ohms

3 G518*

Infinity

Zico

0 to 10

3

1ST

0 to 10

Zealot

Infinity

Thermotime switch

Test terminals

ohms

Airflow meter/MAP sensor

Test terminals

ohms

H. 21199

Small duration

Engine cold:

Auto idle speed control valve

Large duration

ms

%

degrees

Similar to, or above, idle values 4 5.49 4.94 ms

%

H.21203

degrees

Similar to, or above, idle values

Fes,

3.43

3.08

2.4

4.00

3.60

Dio

7.66

6.89

2.2

11.00

9.90

3&4

300 to 600

> 20

>

264

800 to 2500

18

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal

1.5 to 2 (2.6 to 3.5)

Citroen

BOSCH

LE3 JETRONIC

BX 19 TRi & GTi 86 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve Injectors Thermotime switch EGU Water temperature sensor WOANDAARWBNH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays 713 Cold start injector 714 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle contro! valve Not all items fitted to all models

H.19377

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for - approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). The adjuster alters a voltage level to the ECU, and should be carefully turned to achieve the specified CO level. After adjustment, fit a new tamperproof plug.

134

Thema

2000

Refer also to page 39

LE3 JETRONIC

BOSCH

Lancia ie 88 to 8&9

SPECIFICATIONS AT = Auto

M = Manual

N = Non-adjustable

N/A

= Not available/applicable

t+ = Throttle open

* = Throttle closed

Dynamic checks

Static checks

Basic checks

Resistance characteristics

CO at idle (%)

1S to: 20

Injectors (ohms)

750+ 50M 850 + 50 AT

Idle speed (rpm)

Cold start injector (ohms) Auxiliary air valve (ohms)

tO:

Water temperature sensor: (between terminals)

°C 10:

(GF) ¢(50)

20 (68) 80 (176) CO at 3000 rpm (%)

HC at idle (ppm)

Air temperature sensor:

"e

(Pins 1 & 4 in

Injection duration checks

O

piflowenates

CE (32)

20 (68)

Refer to Chapter 2

Injection waveform

H.2/200

_‘|Test terminals

Throttle position switch/sensor

|Test terminals

ohms

3 & 18*

Infinity

2

ie

0 to 10

3 & 487

0 to 10

2.& 183

Infinity

Test terminals

ohms

Test terminals

ohms

H. 21199

Small duration

Engine cold:

Auto idle speed control valve

Large duration

ms

%

degrees

H.21203

Similar to, or above, idle values 4

5.49

4.94

ms

%

degrees

Thermotime

switch

Similar to, or above, idle values

2.5

3.43

3.08

2.4

4.00

3.60

23

7.66

6.89

11.00

9.90

3&4

300 to 600

> 20

> 18

264

800 to 2500

by

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

3 (44) nominal 2 (3.5) nominal

Airflow meter/MAP sensor

Lancia Thema

BOSCH

LE3 JETRONIC

2000 ie 88 to 89

=

GL?

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU. Water temperature sensor WOANDAARWBNH™ 710 Air temperature sensor 771 Pressure regulator 72 Relays 73 Cold start injector 74. Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter 17 Metering head 78 Injector resistors

D = o eU i$ e cha t

ap lem ==

|

ee

=]

'

mal 8 at

19 Load enrichment device

20 Additional idle control valve Not all items fitted to all models H.21103

19

S.

4

1/10/8

aS EA CON (\(\ Ww H.19378

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

Ensure that the engine is at normal operating temperature, and run it for approximately twenty seconds before adjusting the idle speed. Locate the bypass adjuster ‘1’ on the throttle body, and slacken the locknut. Screw in the adjuster to decrease the idle speed, and unscrew the adjuster to increase the speed. Re-tighten the locknut.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). The adjuster alters a voltage level to the ECU, and should be carefully turned to achieve the specified CO level. After adjustment, fit a new tamperproof plug.

136

Peugeot

BOSCH

LE3 JETRONIC

Refer also to page 39

405 GRI, SRI & GTX 88 to 89

SPECIFICATIONS AT = Auto

M = Manual

N = Non-adjustable

N/A

= Not available/applicable

+ = Throttle open

* = Throttle closed

Dynamic checks

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

900 to 950

Injectors (ohms)

Cold start injector (ohms) Auxiliary air valve (ohms) CO at idle (%)

ul).

Water temperature sensor:

°C

(°F)

(between terminals)

10 (50) 20 (68) 80 (176)

Air temperature sensor:

°C

CO at 3000 rpm (%)

HC at idle (ppm)

Injection duration checks

(°E)

(Pins 1 & 4 in

OF (32)

Airflow meter)

20 (68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve __ [Test terminals

Throttle position switch/sensor H.2/200

Small duration

Engine cold:

|Test terminals

ohms

H. 2/199

1

Large duration

ms

%

Se

degrees

H.21203

Similar to, or above, idle values 4

6.16

5.54

ms

%

degrees

Thermotime

switch

3

1.25

Infinity

2

18?

0 to 10

oo

Lop

0 to 10

2 & 187

Infinity

Test terminals

ohms

Test terminals

ohms

Similar to, or above, idle values

2:5

3.45

3.46

2.4

4.00

3.60

2:3

7.66

6.89

2.2

11.00

9.90

344

300 to 600

> 20

> 18

264

800 to 2500

Fuel system checks Fuel pressure - regulator vacuum pipe disconnected - bar (Ibf/in2)

2.5 (36) nominal

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP sensor

Peugeot

BOSCH

LE3 JETRONIC

405 GRI, SRI & GTX 88 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve Injectors Thermotime switch EGU Water temperature sensor ARWNH™ OANA 70 Air temperature sensor 771 Pressure regulator 72 Relays 73 Cold start injector 714 Warm-up regulator 715 Vacuum/pressure switch 76 Fuel filter 717 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle control valve

Z

({er ie 3

Not all items fitted to all models

1/10/8

5

H.19377

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

' , and run it for temperature operating normal at is Ensure the engine approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

g2378

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). The adjuster alters a voltage level to the ECU, and should be carefully turned to achieve the specified CO level. After adjustment, fit a new tamperproof plug.

138

Nova

Refer also to page 39

LE3 JETRONIC

BOSCH

Vauxhall

1.81 87 to 89; Cavalier 1800 87 to 88

1.6 GTE 88 to 89: Astra & Belmont

SPECIFICATIONS N/A

AT = Auto

M = Manual

N = Non-adjustable

= Not available/applicable

+ = Throttle open

* = Throttle closed

Static checks

Dynamic checks

Resistance characteristics

Basic checks

15 to 20

Injectors (ohms) Cold start injector (ohms)

800 to 900 M

Idle speed (rpm)

Auxiliary air valve (ohms) CO at idle (%) 0.5 to 1 (Nova)

/(2R)

Water temperature sensor:

°C

(between terminals)

TOU

(56)

20) }{68) 80 (176) CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

°C

(Pins 1 & 4 in

0) (82)

Airflow meter)

Injection duration checks

(°F)

20

(68)

Refer to Chapter 2

Injection waveform

4.2/200

_‘|Test terminals

Throttle position switch/sensor

|Test terminals

H.21/199

Small duration

Engine cold:

Auto idle speed control valve

SG

Large duration

ms

%

degrees

H.21203

ohms

13%

Infinity

2, Gals*

O to 10

3 Sal 8F

0 to 10

ES

Infinity

Similar to, or above, idle values 4

5.49

4.94

ms

%

degrees

Thermotime switch

Test terminals

ohms

Airflow meter/MAP sensor

Test terminals

ohms

Similar to, or above, idle values 5

3.43

3.08

2.4

4.00

3.60

psa

7.66

6.89

a2

11.00

9.90

3&4

300 to 600

> 20

> 18

244

800 to 2500

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal 1.5 to 2 (2.6 to 3.5)

BOSCH

Vauxhall Nova

1.6 GTE 88 to 89: Astra & Belmont

LE3 JETRONIC

1.81 87 to 89; Cavalier 1800 87 to 88

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve Injectors Thermotime switch ECU Water temperature sensor OANDAARWH™ 10 Air temperature sensor 77 Pressure regulator 72 Relays 73 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 18 Injector resistors 19 Load enrichment device 20 Additional idle control valve

Not all items fitted to all models

W204

H.19680

CO (mixture) adjustment

Idle speed adjustment 1

/dle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for ~ approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO

(mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). The adjuster alters a voltage level to the ECU, and should be carefully turned to achieve the specified CO level. After adjustment, fit a new tamperproof plug.

140

Vauxhall Carlton

BOSCH

LE3 JETRONIC

Refer also to page 39

1.81 87 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

t+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)...........

850 to 900 M

injectors*(Ohims) 4s. oe ge oo seer Cold start injector (ohms) ....... Auxiliary air valve (ohms)........

GOTAUIMO IG) (Phe hoe ron

’

Water temperature sensor:

“C.

(between terminals)

10.

(PF)

(50)

20

(68)

80

(176)

COrat-3000'fpm: (Sojsane HC at idle (ppm).....-...-.

Air temperature sensor:

“Gi

°F)

O

(32)

(Pins 1 & 4 in

20 (68)

Airflow meter)

Injection duration checks Refer to Chapter 2

Injection waveform

4.2/200

ee

ms

ee.

Be Se

we,

ee re

es

AE

ahhh oor

ae

See

ees Se

er b rlnn Ai ee

Throttle position switch/sensor

[Test terminals

ohms

Saris.

Infinity

Pde a

0 to 10

Large duration

Engine cold: ae

_‘{Test terminals

H. 2/199

Small duration

Pe

Auto idle speed control valve

ae ore

ee el : eH

%

degrees

3 & 18tT

0 to 10

2S

Infinity

1ST

Similar to, or above, idle values 4

5.49

4.94

ms

%

degrees

Thermotime

switch

Test terminals

ohms

Test terminals

ohms

344 Sea

300 to 600 800 to 2500

Similar to, or above, idle values

Tse a)

3.43

3.08

2.4

4.00

3.60

7S

7.66

6.89

222

11.00

9.90

& 20

>418

Pb

Fuel system checks Fuel pressure - regulator vacuum

H.21203

he

pipe

disconnected - bar (Ibf/in2) .............:

2.5 (36) nominal

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP sensor

Vauxhall Carlton

BOSCH

LE3 JETRONIC

1.81 87 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve Injectors Thermotime switch ECU. Water temperature sensor DOANDAARWBNH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays 73 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle control valve Not al/ items fitted to all models

H.21105—

CO (mixture) adjustment

Idle speed adjustment 1 Idle bypass adjuster screw

-

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). The adjuster alters a voltage level to the ECU, and should be carefully turned to achieve the specified CO level. After adjustment, fit a new tamperproof plug.

Bosch

LE3 Jetronic

Contents

Injection signal and duration .............cceeeeeeeees cree MrOtties DUELEY SEtLING: 20

6.3 > 12

Airflow meter/MAP sensor

Test terminals 2

3

ohms 25 to 0 to 1000

3.6 to 4.1

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2.5 to 3.1 (36 to 45) 1.5 to 2 (2.6 to 3.5)

Jaguar/Daimler

BOSCH

LH JETRONIC

XJ6 & Sovereign 2.9 86 to 89

Airflow sensor MAP sensor Throttle position switch/sensor

Auxiliary air valve /dle speed control valve Injectors Thermotime switch ECU (under passenger dashboard) Water temperature sensor WOANDAARWBH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays (under passenger dashboard) 13 Cold start injector 14. Warm-up regulator 75

Vacuum/pressure

16 17 78 79 20

Fuel filter (at rear of vehicle) Metering head Injector resistors Load enrichment device Additional idle contro! valve

switch

Not all items fitted to all models

H.2///0

CO (mixture) adjustment 2

;

Idle speed adjustment

Refer to the test procedures dealing with automatic idle speed control and throttle bypass idle setting. Note that the adjusting screw on this application is located on the idle speed control valve body.

CO

(mixture) adjuster screw

CO (mixture) adjustment Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow

meter, and remove the tamperproof plug (where fitted). The adjuster

alters a voltage level to the ECU, and should be carefully turned to achieve the specified CO level. After adjustment, fit a new tamperproof plug.

154

Peugeot

BOSCH

LH JETRONIC

Refer also to page 39

505 V6 86 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

750 to 800 N

Injectors (ohms) Cold start injector (ohms)

15 to 20

Auxiliary air valve (ohms) CO at idle (%)

;

,

Water temperature sensor:

°C

(fF)

(between terminals)

10 (50) 20 (68) 80 (176)

Air temperature sensor:

°C

CO at 3000 rpm (%) percttale. (ppm)

«(°F)

(Combined with

Injection duration checks

Allfowametes)

Refer to Chapter 2 Injection waveform

Auto idle speed control valve

Test terminals 344 4&5 Sra

ohms H. 2/199

ead

Small duration

Engine cold:

Large duration

ms

%

degrees

H.21203

:

Similar to, or above, idle values 3.8

5.04

296

ms

%

degrees

Thermotime

switch

3& 16"

Infinity

2 & 182

0 to 10

3 & 18F

0 to 10

2& 18f

Infinity

Test terminals

ohms

Test terminals

ohms

fe

Similar to, or above, idle values 2.4

Sat

Ure.

pl

3.83

2.29

2nd 2A

V.33 10.50

4.39

6.30

2.83

2.5 to 4

> 20

> 12

346

0 to 1000

Airflow meter/MAP sensor

3.6 to 4.1

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal

1.5 to 2 (2.6 to 3.5)

BOSCH

Peugeot

LH JETRONIC

505 V6 86 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve

/njectors Thermotime switch ECU (under facia) Water temperature sensor DANDAARWNH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays 73 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H. 21/33

aN

HY ) als / i

H.19237

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures.

2

CO (mixture) adjuster screw

Ensure the engine is at normai operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). The adjuster alters a voltage level to the ECU, and should be carefully turned to achieve the specified CO level. After adjustment, fit a new tamperproof plug.

156

Saab

BOSCH

LH JETRONIC

Refer also to page 39

900 Turbo 16V 84 to 8&9

SPECIFICATIONS N = Non-adjustable

M = Manual

N/A = Not available/applicable

AT = Auto

+ = Throttle open

* = Throttle closed

Dynamic checks

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

S5Onr 50

CO at idle (%)

12:0:to 176

Injectors (ohms)

15 to 20

Cold start injector (ohms)

N/A

Auxiliary air valve (ohms)

50 (Pre 1986)

Water temperature sensor:

Ce

Ucr)

110 “f50) 20 (68) 80 (176) CO at 3000 rpm (%)

HC at idle (ppm)

Air temperature sensor: (Combined with

Injection duration checks

Airflow meter)

°C

(°F)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve _—‘|Test terminals 172 (Pts es 213 (1986 to

1989) ohms

H. 2/1/99

ald

Smail duration

Engin

i

sac

Id:

ter sts*

Infinity

2a s*

0 to 10

3 & 18t

0 to 10

2 & 18t

Infinity

Thermotime switch

Test terminals

ohms

Airflow meter/MAP sensor

Test terminals

ohms

Large duration

pes é

% 5

:

d =

Boece

H.21203

Similar to, or above, idle values

3.8

5.35

4.84

ms

%

degrees

Similar to, or above, idle values 2.4

3.4

3.05

PS

3:83

3.44

22.

7.33

6.59

10.50

9.45

2&3

2.5 to 4

> 20

> 18

3&6

0 to 1000

2%]

3.6 to 4.1

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal 1.5 to 2 (2.6 to 3.5)

BOSCH

Saab

LH JETRONIC

900 Turbo 16V 84 to 8&9

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU (under facia) Water temperature sensor DOANDAARWBH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays (inside glove compartment) 73 Cold start injector 714 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

2

CO (mixture) adjuster screw

Early models

Run the engine until it is at normal operating temperature. Locate the idle screw ‘1’, and adjust to achieve the specified idle speed.

Later models

The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures.

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

158

Saab

BOSCH

LH JETRONIC

Refer also to page 39

9000 Turbo 16 & CD Turbo 16 86 to 89; 90001 16 & CDi 16 87 to 8&9

SPECIFICATIONS AT = Auto

M = Manual

N = Non-adjustable

N/A

= Not available/applicable

+t = Throttle open

* = Throttle closed

Dynamic checks

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

850 + 50 850 + 75 (Turbo)

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

3

0.

Water temperature sensor:

Cy

IPE)

10 (50) 20 (68) 80 (176) CO at 3000 rpm (%)

HC at idle (ppm)

Air temperature sensor:

°C

(°F)

(Combined with

Injection duration checks

Suton meter)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve

_‘[Test terminals 182

ha.3 2&3

ohms 4.21200

H. 21199

Small duration

Engine cold:

Large duration

ms

%

degrees

H.21203

Similar to, or above, idle values 3.8

5.35

4.84

ms

%

degrees

Thermotime

switch

SB. 16"

Infinity

Zicy is*

0 to 10

Se Tet

0 to 10

2-S-18T

Infinity

Test terminals

ohms

Test terminals

ohms

Similar to, or above, idle values

2.4

3.4

3.05

2.3

3.83

3.44

2:2

733

6.54

2:1

10.50

9.45

2&3

2.5to 4

> 20

> 18

346

0 to 1000 3.6 to 4.1

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

3 (43) nominal 1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP sensor

Saab

BOSCH

LH JETRONIC

9000 Turbo 16 & CD Turbo 16 86 to 89; 90001 16 & CDi 16 87 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU (under facia) Water temperature sensor DANDARWBH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays (inside glove compartment) 713 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 76 Fuel filter 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H.2/O47

9

6

1/10

1/10 NON- TURBO

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

. The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures. ;

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

160

BOSCH

Volvo

LH JETRONIC

Refer also to page 39

760 GLE 87 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

t+ = Throttle open

Static checks

Dynamic checks Basic checks

Resistance characteristics

Idle speed (rpm)

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Water temperature sensor:

15 to 20

°C (°F) 10 (50) 20 (68) 80 (176)

CO at 3000 rpm (%) HC at idle (ppm)

°C (°F)

Air temperature sensor:

(Combined with Airflow meter)

Injection duration checks Refer to Chapter 2 Injection waveform

Auto idle speed control valve

Test terminals 3&4

20

oa 5

40

445

20

ohms H. 21199

4.2/200

Large duration

Small duration

Engine cold:

ms

%

degrees H.212Z03

Similar to, or above, idle values

3.8

4.72

4.27

ms

%

degrees

Thermotime

switch

oo*

Infinity

2 & 18*

Oto 10

3&4 18T

0 to 10

2&

Infinity

18t

Test terminals

ohms

Test terminals

ohms

Similar to, or above, idle values

2.4

3.05

1.4

2:3

3.83

Aer2

eee,

W233

329

21

10.50

4.72

PL tap}

2.5 to 4

> 20

Ba 4

3&6

0 to 1000

Airflow meter/MAP sensor

3.6 to 4.1

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal 1.5"to 25(2.6'tors.5)

Volvo

BOSCH

LH JETRONIC

760 GLE 87 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve Idle speed control valve Injectors Thermotime switch ECU (in RH footwell) Water temperature sensor ARWBH™ OANA 70 Air temperature sensor 77 Pressure regulator 12 Relays (in centre console) 73 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

HAQNOG

H.20357

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

_ The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). The adjuster alters a voltage level to the ECU, and should be carefully turned to achieve the specified CO level. After adjustment, fit a new tamperproof plug.

Bosch

LH Jetronic

Contents

Injection signal and duration ..........:ceeeeeeeeees Fa... 2. Throttle: DUECTENWYSETLING ...caterer. Aso i ee. 3. PALOTHE POSITION SWIEGN swede ens epi teerrde Eset. kit aR BALTIC AEE VU os ssa iaineae sais os igi ss Pe... Automatic idle speed Control ..........::ceeeseeees 9. Airflow sensor (hot wire type) ..........:eeeeeeeeeees convince

Injection signal and duration

General Wherever possible, it is advantageous to check for an injection signal and the duration as a first test. In many cases, this will provide a good indication of possible faults in the electrical/electronic operation of the system. Refer to Chapter 2 for instructions on how to check for injection signal and duration.

Dynamic checks To obtain an injection signal (unless the test equipment is supplied with an adapter), it is usually easiest to roll back the rubber protection boot on one of the injectors, and touch the test lead to each of the two terminals separately until a signal is obtained. Alternatively, gain access to the ECU terminals with the multi-plug still connected, and refer to the wiring diagram for the appropriate terminals to connect to, to obtain the injection signal. On an engine which will not start, always check the operation of the ignition system first. The injection system relies on a signal

SERRE EE See es

162 162

Watermtemperature.S@ MSO tassreirtirt: ccrcccecaseasssssessMocteooscccctsceessunee [MJ SCTONSR AEA ERT OR csc hc hinints heehee oasteecscceete

165 166

soe eer See cs

162 163 164 164

Fuel system pressure and fuel pump checks ..................cceeeeeee RELATES CK SITIES vein besstacies evades ch atedonewessats te Rete tM canta an setae IMerttaySWitCliie pets. eed ccc cere RE One eo ee ECU checks, fault diagnosis and wiring diagrams

166 168 168

from the ignition system, and will therefore not function if the ECU does not receive an ignition pulse. Check for an injection signal. If there is no signal available at all, refer to the injector checks. If an injection pulse is available, check the duration. If the engine is cold, and the pulse is too small, or if the engine is hot, and the pulse is too large, refer to the water temperature sensor checks. Also refer to the airflow meter checks. If the engine does run, again check the duration cold and hot, and if it is incorrect, refer to the checks as detailed above. If the engine is already hot, refer to the water temperature sensor checks for details of the water temperature simulation test. Check for an increase in the duration during a snap acceleration test, and if it is not acceptable, refer to the airflow meter checks. Also check for injection cut-off during deceleration (where used), and if it is not functioning, check the throttle position sensor. If the above checks appear to provide acceptable results, this generally indicates that the electrical system is satisfactory. If there still appears to be an injection system fault, carry out the fuel pressure checks before any detailed electrical component checks are carried out.

Throttle butterfly setting ©

H,2/200 Injection waveform

The throttle linkage and throttle butterfly are factory-set, and should not normally be adjusted. If it is necessary to check or adjust the butterfly closed position, the following procedure can be used. Slacken off the throttle linkage stop screw on the throttle body until there is a small air gap. Screw the stop screw in an additional half-turn. This should result in an air gap of approximately 0.05 to 0.15 mm (0.002 to 0.006 in) between the throttle butterfly and the throttle casing. On vehicles that do not

H.21205

Throttle butterfly air gap (typical) have an automatic idle speed control, with the idle bypass screw fully closed, the idle speed will typically be around 600 to 650 rpm with the correct butterfly air gap. After setting the butterfly, check thé operation of the throttle position switch or sensor.

Throttle position switch General description The throttle position switch indicates to the ECU the idle and full-load positions, via two sets of contacts in the switch body. When neither of the two switched positions is indicated, a part-load condition is assumed. Mixture correction takes place depending on the switch position. Automatic idle speed control valve operation (where fitted) and deceleration fuel cut-off are also implemented when the idle position is indicated.

Static checks Disconnect the plug from the throttle switch, and either during cranking or with the engine running, check for voltage to the two outer terminals of the connector plug (switch terminals 1 and 3). The voltages

163 Bosch

LH Jetronic

*Note:

/f it is difficult to clamp an air hose

for either of the above tests, one of the hoses should be disconnected, and both openings blanked off. Restart the engine, and note whether

the speed is the same

or reduced.

The same conclusions can be drawn as for tests with the hoses clamped.

Static checks Disconnect the two air hoses from the valve body, and examine the opening of the valve port, either by using a mirror if necessary, or by removing the valve from the engine. The valve should be open if the engine is cold, and closed if the engine has been running for more than five minutes. A valve that has stuck open or closed may benefit from cleaning with a suitable solvent. If a valve still remains closed after cleaning, it will probably need renewing. When a valve remains open, it may be caused either by a broken heater element, or by a faulty electrical circuit to the heating

H.2/202

PARTIALLY OPEN

here 20%,

Regan Bape e472 Gog CU a MAY, hes aig

\

element.

LY. € Tey s res

H.21203 Throttle position switch and terminals originate from the ECU terminals 3 and 12 (refer to the system wiring diagram). The centre terminal of the connector plug Is connected to earth. Check for good continuity, and rectify if necessary. With the plug disconnected and the throttle closed, check for continuity between the centre terminal and the idle terminal of the switch. If it is open-circuit, slacken the securing screws and rotate the switch until continuity exists. If there is still no continuity, renew the switch. Check that the idle contacts open when the throttle is opened. Note: 7he throttle butterfly adjustment should be correctly set before adjusting the idle position switch. Check for continuity between the switch centre terminal and the full-load terminal with the throttle fully open. If there is no continuity, renew the switch. Check that the full-load contacts are open when the throttle is closed.

Auxiliary air valve General description The auxiliary air valve provides a fast idle when the engine is cold, and during the

H.212/4

CLOSED Auxiliary air valve ports initial warm-up period. As the engine warms up, the valve progressively closes, reducing the idle speed to normal. The valve remains open (fast idle) until a combination of engine heat and electrical heating force it to close.

Dynamic checks Engine cold Where possible, clamp shut one of the two air hoses” connecting the air valve to the induction system. If the valve is functioning, the idle speed will drop. If there is no drop in the idle speed, this indicates faulty valve operation. Engine warm Where possible, clamp shut one of the two air hoses* connecting the air valve to the induction system. If the idle speed drops, it indicates faulty valve operation. If there is no drop in idle speed, this indicates correct valve operation.

With the plug disconnected, check for the specified element resistance by measuring across the valve terminals. If the reading indicates a short- or open-circuit, renew the valve. With the plug disconnected, check for battery voltage (engine running or cranking) at one of the plug terminals. The voltage supply originates from the control or system relay (refer to the wiring diagram). If there is no voltage supply at the relay, carry out relay checks. With the ignition off, check for a good earth connection to the remaining terminal on the connector plug. An alternative test can be carried out by independently supplying battery voltage and an earth connection to the valve terminals. The valve should completely close within three to four minutes. If the valve does not close, cleaning with a suitable solvent may effect a cure, otherwise the valve should be renewed.

164

Bosch

Automatic

LH Jetronic

idle speed control

General description The

idle speed

control

is a computer-

controlled air by-pass valve, which carries out idle speed stabilisation requirements, providing fast idle for cold engines, and during warm-up. The valve also compen-

sates for changes in load on the engine when it is idling. An ECU controls the valve opening, by varying the electrical signal. There are two signals which switch the earth circuits for the valve, one each to open and close the valve, and a single voltage supply to the centre terminal of the valve plug.

Dynamic checks Note: Before carrying out the checks, ensure that the throttle switch is correctly adjusted. Also not all dwell meters will provide a

following position note that reading.

If it is suspected that the idle speed control valve is not functioning, roll back the rubber protection boot on the control valve plug, but leave the plug connected. Run the engine, and connect the test lead from either a dwell meter or an oscilloscope that is able to indicate dwell, to each of the outside terminals on the plug (usually terminals 1 and 3).

H. 21233

DWELL PERIOD

Auto idle speed waveform throttle butterfly and bypass idle adjuster settings (refer to ‘throttle bypass idle setting’). If there is no waveform or dwell reading available, carry out the static checks. If a dwell reading or waveform is available from both terminals, with the engine idling, switch on electrical ‘consumers’ such as the headlights or heated rear window. The idle speed may initially drop, but it should be restored to the original speed almost immediately. Note that the dwell reading, or pulse width on the waveform, will increase or decrease, depending on which terminal the test equipment is connected to. For subsequent checks, leave the test lead connected to terminal 1, which should have provided the lower reading. Refer to the Specifications for the correct dwell readings. If there are no readings quoted, use the typical values in this chart (engine warm, no electrical load). Engine type % degrees 4-cyl 30 27 6-cyl 30 78 Apply an electrical load, and the readings should increase by 3 to 4% or more, and the degree value will increase proportionally. If the dwell readings are incorrect, or they do not alter, refer to the static checks, and ensure that the idle control valve is not siezed. Also refer to the throttle bypass setting procedure. If the dwell readings are incorrect, but do alter, refer to the throttle bypass setting procedure.

H. 21232 Auto idle speed control valve A voltmeter can also be used for the test, and any change in the operating signal will be indicated by a small change in voltage. Check for a waveform or dwell reading at each terminal. Note that the two waveforms and readings should differ (refer to the illustration). The dwell readings relate to the width of each pulse on the waveform. A dwell reading or waveform indicates that the ECU is attempting to control the valve. The ECU should then alter the signal when changes in load occur, or if the engine is very cold.

The exact dwell reading at idle, with no load, will depend

perature,

but

on

it will

the ambient

also

depend

air tem-

on

the

Static checks Roll back the rubber protection boot on the control valve plug, and with the engine running, check for battery voltage to the centre wire. If there is no voltage, trace the wiring through to the control relay terminal 87. Disconnect the plug from the valve, and check the resistance between the centre terminal on the valve and each of the outside terminals. Compare the readings with those specified, but note that a fault will usually be indicated by an open-circuit. Also check that there is no continuity between any of the terminals and the casing.

Disconnect the air pipes from the valve, and check that the valve is free to move. It is possible to supply an independent live feed to the centre terminal, and an earth to each of the side terminals in turn, to check that the valve functions, but do not leave the valve connected for more than one second. If the valve appears to be siezed, cleaning with a suitable solvent may effect a cure, but if not, the valve should be renewed. With the plug disconnected from the valve, check for continuity from the two outside wires (terminals 1 and 3) to terminals 10 and 23 of the ECU. If all the electrical checks are satisfactory, and the control valve checks do not prove a mechanical fault, carry out the ECU checks.

Throttle bypass idle setting Note: 7his procedure only applies to vehicles with an automatic idle speed control valve. Note also that on the Jaguar XJ6 2.9, the idle adjuster is located on the idle speed control valve body. If the bypass idle adjuster is screwed to the closed position, the automatic idle speed control valve will open as far as possible, in an attempt to maintain the idle speed. When additional load is applied to the engine, the valve may not be able to open any further to maintain idle speed. Check that the throttle butterfly and throttle switch are correctly adjusted. Refer to the automatic idle speed control dynamic checks, and connect a dwell meter or oscilloscope to the two outside terminalsof the control valve plug. Keep the test lead connected to the terminal that provided the smaller dwell reading, and screw in the bypass idle adjuster. The dwell reading should increase as the idle control valve is opened by the ECU. If the reading decreases, connect the test lead to the other terminal. Adjust the bypass screw so that the dwell reading is as specified. If the specification is not quoted, set the bypass adjuster so that a reading of around 30% (27 degrees for a four-cylinder engine, or 18 degrees for a six-cylinder engine) is measured. Note that when the throttle butterfly and bypass idle adjuster are set correctly, the idle speed will usually be around 100 rpm less than specified when one of the air pipes to the control valve is blocked. If the idle is unstable, refer to the automatic idle speed control checks.

Airflow sensor (hot wire type) General description The airflow sensor is used to indicate to the ECU the amount of air being drawn into

165 Bosch

LH Jetronic

ee

Dynamic checks

the engine. It operates on the ‘hot wire’ principle and therefore has no moving parts. The airflow sensor hot wire is heated to a high temperature just after the engine is switched off, to burn off any contamination.

Carry out an injection duration check, and refer to the specified readings. Checking the duration

Dynamic checks Note: Variations numbers used on system.

occur in the terminal different versions of the

The system operates in a ‘limp-home’ mode if there is a sensor failure. This provides a rich mixture when in operation. Check by disconnecting the airflow sensor plug when the engine is running. This should result in poor running of the engine, due to an excessively rich mixture. With the sensor plug reconnected, the engine should then run correctly. This procedure normally proves correct airflow sensor operation. If there is any doubt, carry out the following checks.

H.21259

Airflow

sensor

terminals

around 350 to 400 ohms (on some applications, the terminals are 6 and 3). Note that if there is a fault, it is usually or short-circuit by an openindicated reading. Disconnect the trunking at the sensor, so that the hot wire element can be observed. With the engine at normal operating temperature, bring the speed to over 2000 rpm for a few moments. Release the throttle, and switch off the engine. After a few seconds, the element should be seen to glow momentarily. If the element does not glow, repeat the test, and check for approximately 4 volts across terminals 1 and 4. If there is no voltage, check the wiring through to the ECU.

Water temperature sensor

Caran iad

General description The water temperature sensor provides a varying voltage signal to the ECU to indicate engine coolant temperature. This enables mixture correction to take place in response to engine temperature changes.

H. 21258 Airflow

sensor

Roll back the rubber protection boot on the airflow sensor plug. With the plug connected and the engine running, connect a digital voltmeter, or oscilloscope test lead, to each of the terminals in turn. Check for a battery voltage supply from the control relay (normally terminal 5 — on some models, this is terminal 2). If there is no supply, trace the wiring through to the control relay. Connect the test lead to the sensor output terminal (normally terminal 3). The voltage should be between 2 to 5 volts, and should vary when the engine speed is increased. If there is no change, carry out the static ; checks.

Static checks Disconnect

the

sensor

plug

from

the

sensor. Check the resistances between the sensor terminals, and compare with those specified. Note that the resistance measured between terminals 6 and 2 will depend on the CO adjuster position — it is typically

Water temperature sensor Plug terminal is blue or white

on a cold engine should

provide a

large duration, which should reduce as the engine warms up. If the engine will not start, the duration can be checked during cranking, but note that the first few moments may provide a higher duration reading than specified. During cranking or running, a substantially smaller than specified duration when cold, or a substantially larger duration when hot, indicates a probable sensor or sensor circuit fault, but refer to the water temperature simulation test.

Static checks Pull off the sensor connector plug, and measure the resistance across the sensor terminals, comparing the readings with those specified. If the sensor is not removed from the engine, it is advisable to take measurements with the engine cold, and then with it hot, to establish the change in resistance in conjunction with the change in temperature. The sensor can, however, be removed and tested in water at various temperatures. If the sensor resistances are correct, check the connections and the continuity of the wiring from the two sensor plug terminals to the ECU and earth (refer to the wiring diagram).

Water temperature simulation test With the engine switched off, pull off the connector plug from the water temperature sensor, and bridge the connector plug terminals with a suitable piece of wire, or preferably, a resistor of approximately 200 to 300 ohms. This will provide a hot-engine simulation. Crank, and if possible, start the engine (run at 1500 rpm), and note the injection duration, which should be close to the specified reading for a warm engine. Switch the ignition off, and remove the bridging wire or resistor. Either leave the plug terminals unconnected, or preferably, bridge with a resistor of approximately 6 Kohms or more, to simulate a cold engine. (This simulation can cause extreme flooding of the engine, preventing starting.) Repeat the test, which should now provide a noticeably larger duration than for the hot-engine simulation. The duration reading should be close to, or greater than, the specified value for a cold engine. If the engine fails to start due to flooding, this indicates correct ECU response. If, during the simulation tests, there is no noticeable difference in the duration measurements, check the sensor plug and

166

Bosch

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ee

eee ee ee eee eee ee

LH Jetronic

ee ee

een

wiring for continuity to the ECU terminal and to earth (refer to the wiring diagram). If there is no wiring fault, suspect the ECU.

connector — disconnect all other system connector plugs and refer to the wiring diagram. If the injection signal exists, but the duration appears to be incorrect, or if the

Injectors

supply voltage is correct and there is still no

General description

injection signal, refer to the ECU Section for a guide to further tests.

The injectors receive a common live feed from the control relay, and are switched on and off on the earth circuit, through the ECU. On six-cylinder engines, the injectors are switched in two groups of three.

Dynamic checks Crank or run the engine, and listen to each injector for a clicking sound as the injector operates (it may be necessary to use a suitable listening device, such as a screwdriver, as a ‘stethoscope’). If it appears that an injector is not functioning, carry out the static check. If the static check results are acceptable, check for continuity of the wiring between the injector plugs and the ECU multi-plug — disconnect all connector plugs for this test, and refer to the wiring diagram. If a// the injectors (four-cylinder engines), or all the injectors of one or both groups (six-cylinder engines), are not functioning, carry out the following checks.

checks

Static checks Remove the plug from the injector(s), and check the resistance across the two injector terminals, comparing with the reading specified. Also ensure that there is no continuity between the injector body and the injector terminals. Note: /f there is no fault found during the above checks, but it is apparent that one or more injectors are not functioning correctly, it is possible that fouling exists in the faulty injectors, and a flow rate test may be required — refer to Chapter 2.

Fuel system pressure pump checks

and

fuel

Fuel pump relay — bypassing For a number of the following tests, it Is necessary to crank the engine, in order to allow the pump to run. It is possible to by-pass the pump relay, which will allow the pump to run without cranking. Locate and remove the pump relay, which also acts as the system relay. Bridge the connectors on the relay holder which correspond terminals 30 (battery positive) and 87b (pump supply). The bridging wire should be fitted with a 20 amp fuse, to protect against a possible short-circuit.

Fuel system pressure checks The system should provide fuel to the fuel rail and injectors, at a pressure which is

AH. 2/202

Connection to an injector Check the injection signal and duration, and if correct, carry out the static injector check. If there is no injection signal, crank the engine and check for a supply voltage to the injector plugs from the control relay (refer to the wiring diagram), and carry out relay checks if necessary. Check for continuity of the wiring from the

injector

plugs

to

the

ECU

multi-plug

H 21207

Bridging a relay with a 20A fuse

nee

es

constant in relation to manifold pressure. The system consists of a pump (some applications have an additional pump in the tank), main filter, fuel rail (to distribute the fuel to the injectors) and injectors, which contain a fine filter. To maintain the pressure, a pressure regulator is fitted, which allows excess fuel back to the tank. The regulator is connected to the inlet manifold via a vacuum pipe, in order to adjust the fuel pressure in conjunction with changes in the manifold pressure. Warning: Before disconnecting any of the fuel lines, it is advisable to disable the fuel pump and run the engine, to depressurise the fuel system. The fuel pump relay is incorporated in the system relay, preventing the pump supply from being disconnected without disabling the rest of the injection system. It is therefore necessary to independently disconnect the fuel pump electrical connections directly at the pump. Disable the fuel pump, and run the engine until it stops, to depressurise the fuel system. Locate the fuel supply line to the fuel rail, and disconnect the supply line. Connect the fuel pressure gauge as indicated in equipment manufacturer's instructions. Wherever possible, locate a tap between the gauge and the fuel rail. Reconnect the fuel pump, and start the engine (make sure that if a tap is fitted with the gauge, it is in the ‘open’ position). If the engine will not start, crank the engine, or bypass the relay, which will allow the pump to operate and provide the’ required pressure. Note the fuel pressure. Disconnect the vacuum pipe connecting the fuel pressure regulator to the inlet manifold, and plug the hole to the manifold. The fuel pressure should increase to the specified value. (During cranking, the engine only produces a low vacuum level, therefore the fuel pressure will be very close to the specified level even if the vacuum pipe remains connected). Also note that on an engine which is running, the same test can be carried out using a CO reading, which should increase in conjunction with the fuel pressure increases. Note: A/though the system pressure may be correct when the engine is running under workshop test conditions, it does not prove that the pressure and fuel flow are acceptable at high engine speeds and l/oads. Unless the pressure can be checked with the vehicle on a rolling road, it will be necessary to carry out fuel pump checks, to establish whether the pump can supply sufficient fuel at the required pressure when the fuel demand is high.

Bosch

167

LH Jetronic

PRESSURE REGULATOR

through a main filter before reaching the fuel rail and injectors. On applications with an additional pump in the tank, this acts as a

FUEL RAIL

EXCESS FUEL RETURN

priming pump for the main pump. The electrical supply for the pump(s) Originates at the pump relay. The relay will not, however, switch on the pump until the

control relay is also switched on. Note that when there are two pumps, they share a common power supply, and therefore operate together.

INJECTOR

Crank the engine, and listen for pump operation. If the pump is not running, check for battery voltage to one of the connections at the pump by repeating the test. If the supply voltage is not available, check the wiring through to the pump relay (refer to the wiring diagram), and carry out relay checks if necessary. Check for a good earth on the remaining connection at the pump, and rectify if necessary. If the electrical connections and supply voltage are satisfactory, but the pump will

FUEL TANK FUEL PUMP

-

Fuel system With the engine running, if the fuel pressure is already at the specified level prior to disconnecting the regulator vacuum pipe, the pressure regulator is likely to be faulty, but ensure that manifold vacuum is available from the vacuum pipe, and that there are no leaks. If the fuel pressure is higher than specified, it indicates a faulty pressure regulator, but it is possible for a blockage on the return line from the regulator to cause a high

FUEL RAIL

FUED SUPPLY

—

system pressure.

Attach an independent pipe to the pressure regulator on the return pipe connection, run the engine and allow the fuel to drain into a suitable container. If the fuel pressure is now at the specified level, check the . vehicle return line for a blockage. If the pressure is still high, renew the regulator. If the fuel pressure is lower than specified, it is possible that the regulator is faulty, but the most likely cause is a faulty fuel pump, or a severe blockage in the fuel filter or supply line. Where possible, with the engine running or cranking, briefly clamp the fuel return line from the regulator. If the pressure now rises substantially, it indicates a regulator fault. If the pressure remains low, carry out the fuel pump checks, and also look for a fuel leak between the pump and the regulator.

H.2/209 Connecting a pressure gauge

Fuel pump and filter checks ‘The fuel pump is able to provide the system with a greater quantity of fuel than is required to run the engine. The excess fuel is passed back to the tank via the fuel pressure regulator. The fuel passes from the pump

Pressure regulator

not run, it should be renewed. When carrying out the system pressure checks, if the pressure is low, or if it is suspected that the pump is failing when the fuel demand is high, it will be necessary to carry out a flow rate and maximum-pressure check. If a pressure gauge and tap can be connected to the system (refer to the first fuel system pressure check), turn the tap to the ‘off’ position, and crank the engine until a maximum pressure reading is reached. The pressure should reach approximately 5 bar (75 Ibf/in?) or more. If the pressure is too low, it indicates a pump fault. Check that, if a tank pump is fitted, it is providing sufficient flow to feed the main pump. It is unlikely that a filter blockage will prevent the pressure from reaching the required level, unless the blockage is very severe.

168

Bosch

LH Jetronic

————— NN lf the maximum pressure is acceptable, it is still advisable to carry out a flow rate check.

Disconnect

the fuel supply line from

the fuel rail, and allow the fuel to drain into a suitable container. The test should ideally be

carried out for a period of at least thirty seconds. It will therefore be advisable to bypass the fuel pump relay, to allow the pump

to run

without

cranking

the engine

(refer to ‘fuel pump relay — bypassing’). Run the pump, and note the fuel quantity delivered, comparing with the specified value. A low output would indicate a probable pump fault, but a check should be made for blockages in the lines and the filter, as detailed in the following paragraph. Disconnect the fuel supply line from the filter, and repeat the fuel flow rate test by running the fuel directly from the pump to the container. If the flow rate is now close to that specified, the filter should be renewed. If the flow rate is still too low, check the fuel flow from the tank pump (where fitted), and renew it if its operation is suspect. If there is no tank pump, and the delivery rate is low, renew the (main) pump.

Relay checks General description Two relays are used, to provide a switched supply voltage to the injection system and fuel pump(s). The relays require certain items of electrical information before they will switch on the system components.

Static checks Note: Refer to the wiring diagram carrying out the following checks.

when

If, during the ECU check, it supply voltage relay, check component

airflow sensor check or the is found that there Is no available from the control for continuity from the

to the relay terminal, and rectify

if necessary. Remove

the

relay,

and

connect

battery

positive to relay terminal 86, and connect terminal 85 to earth. The relay should be heard to operate but also check that the contacts are closed, by checking for continuity between terminals 30 and 87, and terminals 30 and 87b. If there is no continuity, renew the relay. If the relay appears to operate, check for a permanent live feed to the relay holder connection corresponding to relay terminals 30 and 86. If there is no voltage, trace the wiring back to the battery. Check that the relay holder connection 85 is connected to the ECU terminal 21. If, when carrying out checks on the injectors, idle speed control system, or fuel pumps, it is found that there is no supply voltage from the pump relay, check the wiring from the component to the relay, and rectify if necessary. Remove the relay, and connect battery positive to relay terminal 86, and connect terminal 85 to earth. The relay should be heard to operate, but also check that the contacts are closed, by checking for continuity between terminals 30 and 87, and terminals 30 and 87b. If there is no continuity, renew the relay. If the relay appears to operate, check for a permanent live feed to the relay holder connection corresponding to terminal 30. If

there is no voltage, trace the wiring back to the battery. Check for a live feed from terminal 87 of the control relay to terminal 86 of the pump relay with the ignition on, and if necessary, carry out a check on the control relay. Check that the relay holder connection corresponding to relay terminal 85 is connected to the ECU terminal 17.

Inertia switch

General description An inertia switch is fitted on some vehicles, which will cut off the electrical supply to the fuel pump, and possibly other components, in the event of an accident.

Static checks If it is apparent that there is no live feed to the pump or other components, locate the inertia switch, and check for continuity between the two terminals. If the switch ts open (no continuity), operate the reset button. If the switch is still open, renew it.

H.2/216

Typical inertia switch

Live feed to terminal

5 Airflow meter

Live feed to terminal pump relay

9 ECU

and terminal 86 Fuel

O Terminal 21 ECU O Battery

+ve

O Battery +ve Q Live feed to fuel pump Live feed to injectors, auxiliary air valve, idle speed control valve C

Live feed from terminal 87 Main control

Q

Terminal

Q Battery

H. 2/260

Relay wiring diagram

17-ECU

+ve

relay

ECU

checks — Bosch

LH Jetronic

General It is not possible, without dedicated test equipment, to carry out a direct check on the ECU. It is, however, possible to establish whether or not the ECU is functioning by carrying out the following tests. The tests are divided into two categories — one with the ECU multi-plug connected, and one with the multi-plug disconnected. It should be possible with these tests to establish that all the

connections to the system components are satisfactory, and that all the relevant signals are being passed from the sensors to the ECU. If the ECU is still not providing the correct output signals to the injectors, then the ECU should be substituted. Warning: Do not disconnect the ECU multi-plug with the ignition switched on.

ECU multi-plug terminal

Multi-plug connected (Yes/No)

Test to be carried out

1 13 18

Yes Yes Yes

Check for primary ignition signal during cranking, or when running Check connection to fuel injectors, and for signal to fuel injectors, during cranking, or when running Check for ignition feed during cranking, or when running

2 3 5 6 7 8 S] 10 11 12 14 15 17 19 20 71 22 23 25

No No No No No No No No No No No No No No No No No No No

Check connection Check connection Earth connection Check connection Check connection Check connection Check connection Check connection Earth connection Check connection Check connection Earth connection Check connection Check connection Check connection Check connection Check connection Check connection Earth connection

to water temperature sensor to throttle switch terminal 1

to to to to to

airflow meter terminal 2 airflow meter terminal 3 airflow meter terminal 4 main control relay terminal 87 idle speed control valve terminal 1

to throttle switch terminal 3 to airflow meter terminal 6

to to to to to to

fuel pump relay terminal 85 test connector Lambda sensor (if fitted) main control relay terminal 85 test connector idle speed control valve terminal 3

170

Fault diagnosis — Bosch

LH Jetronic

Test components in the order given alongside specific faults

filter fuel and relay Fuel pump pump,relays regulator Fuel pressure duration and signal Injection from supply Powerrelay signal Ignition to Injectors meter/sensor Airflow Water temperature sensor control speed idle valve air Auxiliary or switch/sensor position Throttle Engine will not start

Poor cold starting Poor hot starting Loss of power

*

..............

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High CO at idle (adjuster Ineffective) ac.n.cter i eee Low

CO at idle (adjuster

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...........c..00000

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Excessive fuel CONSUMPTION

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171 Bosch

Injection

LH Jetronic

ECU

O

Earth connection

QO Terminal 87B Main control relay

Water temperature sensor

Airflow meter

Throttle switch

H.2126/

Bosch

LH Jetronic wiring diagram

Injection

ECU

Terminal

87

Fuel pump relay

Cylinder 1

Cylinder 2

Cylinder 4

Cylinder 3

Cylinder 5

Injectors Note: 4 and 8-cylinder models are the same as above

Bosch

LH Jetronic wiring diagram

Cylinder 6 H.2/1262

7

2

Bosch

LH Jetronic

Injection ECU

O Terminal

1 Coil

Test connector

O

es

eta ea |

Auxiliary air valve (early models)

Earth connection

GC Terminal

87

Fuel pump relay

H, 21263

eos

Idle speed control valve

Bosch

LH Jetronic wiring diagram

Injection ECU

O

Ignition ECU

©

Earth connection

Terminal 87 Main control relay

Water temperature

sensor

Throttle sensor

Airflow meter

H.21264A

Bosch

LH Jetronic wiring diagram for Jaguar 2.9

173 Bosch

Fuel pump

relay

Main

control

LH Jetronic

relay

VA 30)

86)

85).

87

30}

O60

5| 2 987

Live feed to terminal 86 Fuel pump ECU, terminal 2 Airflow meter Terminal

21

Battery

+ve

Battery

+ve

relay, terminal

9

ECU

0 Live feed to injectors, fuel pump, Lambda sensors, idle speed

H.2)2G48

Bosch

O

Terminal

O

Live feed from terminal

O

Battery

Y

17 ECU 87 Main

control relay

+ve

LH Jetronic wiring diagram for Jaguar 2.9 Injection ECU

©

Terminal 1 Coil

O

Instrument

O

Earth connection

C)

Terminal 87 Fuel pump

H.21264C

~

Idle speed control valve

Bosch

14

15

16

Lambda

sensor

LH Jetronic wiring diagram for Jaguar 2.9

17

8

ECU

19

20

terminals

21

22

23

13

12

n

10

9

8

7

6

5

4

3

2

1

Heated

24

25

pack

relay

174

Alfa Romeo

BOSCH

MOTRONIC

(EARLY SERIES)

Refer also to page 39

Alfetta 84 to 85

SPECIFICATIONS AT = Auto

M = Manual

N = Non-adjustable

N/A

= Not available/applicable

‘+ = Throttle open

* = Throttle closed

Dynamic checks

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

900 + 50

Injectors (ohms)

Cold start injector (ohms) Auxiliary air valve (ohms) CO at idle (%)

Os

Water temperature sensor:

PC)

(7 R)

(between terminals)

10 (50) 20 (63) 80 (176)

Air temperature sensor:

°C

CO at 3000 rpm (%) HC at idle (ppm)

(Pins 22 & 6 in

O (32)

Airflow meter)

Injection duration checks

(°F)

20

(68)

Refer to Chapter 2

Injection waveform

H.2/20/ Small duration

gine co Id: Engi

Auto idle speed control valve

_|Test terminals

Throttle position switch/sensor

|Test terminals

ee Large duration

m s

%6

Sida?

d egrees e

reyes

Similar to, or above, idle values 4 5.99 5.39 ms

%

Infinity

2,13"

0 to 10

secaton

Oto 10

2& 18t

Infinity

Test terminals

ohms

ee.

W & Switch body

degrees

20

> 13

6&7

50 to 2000

Snap open throttle Dwell readings are invalid on dwell meters

Fuel system checks Fuel pressure - regulator vacuum

Role

ohms

pipe

disconnected - bar (Ibf/in?)

2.5 to 2.8 (36 to 40)

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

H.2/235

Alfa

BOSCH

Romeo

MOTRONIC

(EARLY SERIES)

Alfetta 84 to 85

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve

/dle speed control valve /njectors Thermotime switch ECU (under facia) Water temperature sensor DOANDAAARWBH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays 73 Cold start injector 714 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 719 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H.19270

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

Ensure that the engine is at normal operating temperature, and run it for approximately twenty seconds before adjusting the idle speed. Locate the bypass adjuster ‘1’ on the throttle body, and slacken the locknut. Screw in the adjuster to decrease the idle speed, and unscrew the adjuster to increase the speed. Re-tighten the locknut.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

176

BMW

BOSCH

MOTRONIC

(EARLY

SERIES)

Refer also to page 39

3251 & 325iX 85 to 87

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

as

Injectors (ohms)

Cold start injector (ohms) Auxiliary air valve (ohms) CO at idle (%)

+20;

Water temperature sensor:

°C 1 (°F)

(between terminals)

10 (50) 20 (68) 80 (176)

Air temperature sensor:

SC.

CO at 3000 rpm (%) HC at idle (ppm)

(Pins 22 & 6 in

O (32)

Airflow meter)

Injection duration checks

VE)

20

(68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve _| Test terminals 3&4 445 Scere

ohms

we ma

pale

:

binone

g

uration

ngine co Id: Engi

H2//98 arge

ms

%0

duration

d gorees

Fm ea

Similar to, or above, idle values 4

5.66

3.39

ms

%

degrees

2 & 18*

0 to 10

3 & 18f

0 to 10

2 & 18+

ive Infinity

Test terminals

ohms

35° C795? F

Oto 10

ohms

Zo

3.50

2.10

2.4

4.00

2.40

293

7.66

4.59

Test terminals

11.00

6.60

6&9

20

PAZ

6&7

50 to 2000

Snap open throttle Dwell readings invalid on dwell meter

Fuel system checks Fuel pressure - regulator vacuum

2°48

Test terminals

Similar to, or above, idle values

disconnected - bar (Ibf/in2)

Infinity

pipe

2.5 to 3 (36 to 43) H. 21235

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

BMW

BOSCH

MOTRONIC

(EARLY SERIES)

525e 83 to 88

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve

/njectors Thermotime switch ECU (under facia) Water temperature sensor DWANDAARWH™ 70

Air temperature sensor

77 72 13 14 75 16 17 18 79 20

Pressure regu/ator Relays Cold start injector Warm-up regu/ator Vacuum/pressure switch Fuel filter (at rear of vehicle) Metering head /njector resistors Load enrichment device Additional idle control valve

Not all items fitted to all models

H.19392 H.19391

CO (mixture) adjustment

Idle speed adjustment

7

Idle bypass adjuster screw

Run the engine until it is at normal operating temperature. Locate the idle screw ‘1’, and adjust to achieve the specified idle speed.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

180

BMW

BOSCH

MOTRONIC

(EARLY

SERIES)

Refer also to page 39

5351 & M535i 85 to &8

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

SoUeT

oO

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

OS 16 1.4

Water temperature sensor:

(between terminals)

TO S750) 20 (68) 80 (176)

Air temperature sensor:

°C.‘

AOS

20 (68)

CO at 3000 rpm (%) SAE

a Cal Tet)

(Pins 22 & 6 in

Injection duration checks

(°F)

O (32)

BS EH,

Refer to Chapter 2

Injection waveform

Auto idle speed control valve

_‘{Test terminals 3&4 4&5 Sa 5

ohms W.2/201

H21198

Small duration

Engine cold:

Large duration

ms

%

degrees

H.21203

Similar to, or above, idle values 4

5.66

3.39

ms

%

degrees

277 195

0 to 10

ot Lay

0 to 10

2&

Infinity

18t

ohms

W & Switch body < 30°C/86°F

0 to 10

PAS)

3.50

2.10

2.4

4.00

2.40

20

7.66

4.59

Test terminals

ohms

22

11.00

6.60

6&9

< 2100

> 20

le

Ga 7

Snap open throttle Dwell readings invalid on dwell meter

Fuel system checks Fuel pressure - regulator vacuum

Infinity

Test terminals

Similar to, or above, idle values

disconnected - bar (Ibf/in2)

3 & 18*

pipe

3 (43) nominal H.21235

Pump delivery - litres/min (pints/min)....

2.2 (3.9) nominal

50 to 2000

BMW

BOSCH

MOTRONIC

(EARLY SERIES)

5351 & M535i 85 to 8&8

Airflow sensor MAP sensor Throttle position switch/sensor

Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU (under facia) Water temperature sensor DWANDARWBH™ 70 Air temperature sensor 771 Pressure regulator 72 Relays 13 Cold start injector 14 Warm-up regulator 715 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H.19390

H.19392

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

182

BMW

BOSCH

MOTRONIC

(EARLY SERIES)

Refer also to page 39

635 CSi 82 to 89: 7321 & 735i 82 to 86

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)...........

of

Injectors: (Ohms) ,gee sree... «f. Cold start injector (ohms)

.......

4

Auxiliary air valve (ohms)........ GO atidie (26) . 2. 8eee.es

1.5 max

COvat 3000 rpm. (96) eat

|

Infinity

eee

SO000-rom

Acie

6

So Los

(6) tap Y/

Dwell readings invalid on dwell meter

Fuel system checks Fuel pressure - regulator vacuum pipe disconnected - bar (Ibf/in2)..............

3 (43) nominal

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

H.21235

50 to 2000

BMW

BOSCH

MOTRONIC

(EARLY SERIES)

635 CSi 82 to 89: 732i & 735i 82 to 86

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control! valve

/njectors Thermotime switch ECU (under facia) Water temperature sensor DOANDAARWH™ 70 Air temperature sensor 771 Pressure regu/ator 72 Relays 713 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 /njector resistors 19 Load enrichment device 20 Additional idle contro! valve Not all items fitted to all models

H 2/118

| H.19390

na392 CO (mixture) adjustment

Idle speed adjustment 71

_

Idle bypass adjuster screw

The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO or unscrew the adjuster to reduce the CO level. Set the CO reading tc that specified, and fit a new tamperproof plug.

184

BMW

BOSCH

M5 86 to 88; M635

MOTRONIC

(EARLY

SERIES)

Refer also to page 39

CSi 85 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

350 = 00

Injectors (ohms)

Cold start injector (ohms) Auxiliary air valve (ohms) CO at idle (%)

0.3 to 1.5 (M5)

Water temperature sensor:

©C

4(-E}

1.5 max (M635))

(between terminals)

10

(50)

20 (68) 80 (176) CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

°C--

(Pins 22 & 6 in

O (32)

Airflow meter)

Injection duration checks

(°F)

20

(68)

Refer to Chapter 2

Injection waveform

H.2/201

Auto idle speed control valve

_|Test terminals

Throttle position switch/sensor

|Test terminals

ohms

3.67165

Infinity

Zio.

0 to 10

3.& 167

Oto 10

2 & 18t

Infinity

Test terminals

ohms

ga

Small duration

Large duration

Engine cold:

ms

%

degrees

H.21203

Similar to, or above, idle values 4 5.66 3.39 ms

%

W & Switch body

degrees

Similar to, or above, idle values

435 6795-5

Oto 10

- 1225

3.50

2.10

2.4

4.00

2.40

233

7.66

4.59

Test terminals

ohms

dvd,

11.00

6.60

6&9

< 2100

ast)

Pe

Grech,

50 to 2000

Snap open throttle Dwell readings invalid on dwell meter

cd

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe 3 (43) nominal H. 2/1235

Pump delivery - litres/min (pints/min)....

2.2 (3.9) nominal

BMW

BOSCH

MOTRONIC

(EARLY SERIES)

M5 86 to 88; M635 CSi 85 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve [Injectors Thermotime switch ECU (under facia) Water temperature sensor DANDAARWBH™ 70 Air temperature sensor 77 Pressure regu/ator 72 Relays 73 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve

eel

ii|

Not all items fitted to all models

H.19392

H.19390

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idie bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

186

Porsche

BOSCH

MOTRONIC

(EARLY SERIES)

Refer also to page 39

911 Carrera & Speedster 84 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

t+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

800 + 20 N

Injectors (ohms) Cold start injector (ohms)

Auxiliary air valve (ohms) CO at idle (%)

L.0 to t.5

Water temperature sensor:

(°F)

10 (50) 20 (68) 80 (176) CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

°C

(Pins 22 & 6 in

O

Airflow meter)

Injection duration checks

(°F)

(32)

20

(68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve

_‘|{Test terminals 3&4 445 Gita

Engine cold:

g

ohms

H2//98

H. 2/201 Small duration

3 & 13%

Infinity

2 & 18*

Oto 10

3 & 18T

0 to 10

—2-& 18+

ark Infinity

Thermotime switch

Test terminals

ohms

Airflow meter/MAP sensor

Test terminals

ohms

Large duration

ms

G

:

Me)

degrees

9

Lal

Similar to, or above, idle values 4

5.66

BAO

ms

%

degrees

Similar to, or above, idle values 25

350

ZN

2.4

4.00

2.40

2a

7.66

4.59

11.00

6.60

6&9

< 2100

> 20

pg) eZ

6&7

50 to 2000

Lae,

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in2)

pipe

2.5 (36) nominal H.21235

Pump delivery - litres/min (pints/min)....

1.7 (3) nominal

Porsche

BOSCH

MOTRONIC

(EARLY SERIES)

911 Carrera & Speedster 84 to 89

156 S41

9...6

1/10 Airflow sensor MAP sensor Throttle position switch/sensor

‘=

Auxiliary air valve /dle speed control valve Injectors Thermotime switch ECU (under driver's seat) MOAN Whom» DAAWater temperature sensor 70 Air temperature sensor

ae

)

o

I]

77 Pressure regulator 12 Relays (under driver's seat) 73 Cold start injector 74 Warm-up regulator

oe

LI

75

Vacuum/pressure

76 17 78 79 20

Fuel filter Metering head Injector resistors Load enrichment device Additional idle control valve

switch

Not all items fitted to all models H. 21/38

H.20410

H.20409

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

-

The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures.

2

CO

(mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

188

Volvo

BOSCH

MOTRONIC

(EARLY SERIES)

Refer also to page 39

760 Turbo 83 to 89; 740 Turbo 86 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

CO at idle (%)

850 (up to 1984)

Injectors (ohms)

1S to ZO

900 (from 1984)

Cold start injector (ohms)

4

Auxiliary air valve (ohms)

50 (early 760 models)

1 to 2.5 (up to 1984)

Water temperature sensor:

°C

(°F)

0.5 to 2 (from 1984)

(between terminals)

10 (50) 20 (68) 80 (176)

Air temperature sensor:

°C

ohms

5000 2500 300

CO at 3000 rpm (%) HC at idle (ppm)

(Pins 22 & 6 in

O (32)

Airflow meter)

Injection duration checks

(°F)

20

(68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve

_‘[Test terminals 3&4 445 345

Engine cold:

g

ohms

H2//98

H. 2/201 Small duration

St

Large duration

ms

%

:

degrees

2

dens

Similar to, or above, idle values 4 5.99 5.39 ms

%

i

i

Similar to, or above, idle values

225

3.74

3.36

2.4

4.00

3.60

2000 rpm

23

7.66

6.89

3000 rpm

2.2

11.00

9.90

2720

>is

Snap open throttle

i

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal 1.5 to 2 (2.6 to 3.5)

21& 13*

Oto 10

3&

18t

0 to 10

2 & 18t

Infinity

Test terminals

ohms

< 30°C/86°F

0 to 10

Test terminals

ohms

6&9 6&7

< 2100 50 to 2000

;

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in2)

Infinity

W & Switch body

degrees

1000 rpm

1sS*

W.21235

BOSCH

Volvo

MOTRONIC

(EARLY SERIES)

760 Turbo 83 to 89; 740 Turbo 86 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU (in driver’s footwel/) Water temperature sensor DANDAARWNH™ 70 Air temperature sensor 771 Pressure regulator 72 Relays (behind centre console) 73 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 76 Fuel filter (at rear of vehicle) 17 Metering head 18 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not all items fitted to all models H.AI/7

H.19408 H.19409

CO (mixture) adjustment

Idle speed adjustment 71

Idle bypass adjuster screw

2

CO

(mixture) adjuster screw

Early models Run the engine until it is at normal operating temperature. Locate the idle screw ‘1’, and adjust to achieve the specified idle speed.

Later models

The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures.

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

Bosch

Motronic

(early series)

Contents

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190

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..................00000e

195

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196

191 192 192

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Poor cold starting Poor hot starting LOSS OF IPDOWGE? Flat spot under

acceleration

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regulator Fuel pressure Injectors

..............

7

6

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.............c.0008

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rrrtre hrestiees tecase

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.....: 20

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2.102,

1S oRO GD)

1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP sensor

Test terminals

Refer to test procedures

HONDA

Honda

PGM.-FI

Civic CRX 87 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve

/dle speed contro! valve /njectors Thermotime switch ECU (under driver's seat) Water temperature sensor DOANAARWBNH™ 70 Air temperature sensor 77 Pressure regulator 12 Relays (under driver's facia) 73 Cold start injector 14 Warm-up regulator 75

Vacuum/pressure

76 17 78 79 20

Fuel filter Metering head Injector resistors Load enrichment device Additional idle control valve

switch

Not all items fitted to all models

\ ee

TasSs

G

?

aN

2) H.19656

-

Idle bypass adjuster screw

The engine is fitted with an automatic idle speed control, eliminating the need to adjust the idle as a service procedure. A basic getting is, however, achieved by observing the yellow LED display located on the ECU under the driver's seat. If the basic setting is incorrect, the LED will be flashing, or permanently on. Adjust the bypass screw ‘1’ on the throttle body until the LED goes out.

er\ 4 H.12852

CO (mixture) adjustment

Idle speed adjustment 7

WC

Lea

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the control box, and remove the tamperproof plug. Using a suitable screwdriver, adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof plug after adjustment.

354

HONDA

Honda

PGM.-FI

Refer also to page 39

Integra EX 16 86 to 89; Shuttle 1.61 4WD 88 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

CO at idle (%)

780 + 50 800 + 50 M (Integra)

Injectors (ohms) Cold start injector (ohms)

750 + 50 AT (Integra)

Auxiliary air valve (ohms)

22

= 20

2.0

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2:3 to'2.7+(33'to"39) 1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP sensor

Test terminals

Refer to test procedures

Honda

HONDA

PGM.-FIl

Legend 2.7 & Coupe 88 to 89

13

ity 10 wAlSralBheoie2 Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed contro! valve

Injectors Thermotime switch ECU (under driver's seat) Water temperature sensor DOANDAARWH™ 10 Air temperature sensor 77 Pressure regulator 72 Relays (under driver's facia) 73 Cold start injector 14. Warm-up regulator 15 Vacuum/pressure switch 16 Fuel filter 17 Metering head 718 Injector resistors 19 Load enrichment device 20 Additional idle control valve ETT

>

Not all items fitted to all models

NE

ban

H.19670

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

The engine is fitted with an automatic idle speed control, eliminating the need to adjust the idle as a service procedure. A basic setting is, however, achieved by observing the yellow LED display located on the ECU under the driver's seat. If the basic setting is incorrect, the LED will be flashing, or permanently on. Adjust the bypass screw ‘1’ on the throttle body until the LED goes out.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the control box, and remove the tamperproof plug. Using a suitable screwdriver, adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof plug after adjustment.

360

Rover

HONDA

PGM.-FI

Refer also to page 39

825i & Sterling 86 to 88

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

t+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

770+

50 N

Injectors (ohms)

Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

0150-25

Refer to test procedures

Water temperature sensor: (between terminals)

°C (°F) 104 ¢50} 20 (68) 80 (176)

Air temperature sensor:

°C

ohms 3500 2400 300

CO at 3000 rpm (%) Peeping

(between terminals)

(°F)

6. (32)

Injection duration checks

20

(68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve _‘|Test terminals Refer to test procedures

Throttle position switch/sensor 42/200

H. 2/199

Small duration

Engine cold:

Large duration

ms

%

2

Engine warm: Cranking

2.62

ms

%

degrees

Zia

2.07

Tae

ane

3.66

2Ag

7.00

4.2

S99

a9

pied

220

Fuel system checks Fuel pressure - regulator vacuum

3200 to 7200

Ci2 & 67

0 to 7200

Thermotime

switch

Test terminals

Similar to, or above, idle values

Zonk

disconnected - bar (Ibf/in?)

C12-&-C1,8

to fully open)

Similar to, or above, idle values 4.35

ohms

(Throttle closed

degrees

3.5

|Test terminals

pipe

Pump delivery - litres/min (pints/min)....

2:3%0°2179(33"to'S9) 1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP sensor

Test terminals

Refer to test procedures

HONDA

Rover

PGM.-FI

825i & Sterling 86 to 88

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU (under driver's seat) Water temperature sensor DOANDARWBNH™ 70 Air temperature sensor 17 Pressure regulator 712 Relays (under driver's facia) 73 Cold start injector 14 Warm-up regulator 715 Vacuum/pressure switch 76 Fuel filter 17 Metering head 78 /njector resistors 19 Load enrichment device 20 Additional idle control! valve Not all items fitted to all models

H2/0/0

H.19291

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

The engine is fitted with an automatic idle speed control, eliminating the need to adjust the idle as a service procedure. A basic setting is, however, achieved by observing the yellow LED display located on the ECU under the driver's seat. If the basic setting is incorrect, the LED will be flashing, or permanently on. Adjust the bypass screw ‘1’ on the throttle body until the LED goes out.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the control box, and remove the tamperproof plug. Using a suitable screwdriver, adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof plug after adjustment.

362

Rover

HONDA

PGM.-FI

Refer also to page 39

827Si, 827SLi, Sterling & Vitesse 88 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

7T20

50IN

Injectors (ohms)

Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Ore

0:25

Refer to test procedures

Water temperature sensor: (between terminals)

©Cr (PF) 104 4(50) 20 (68) 80 (176)

ohms 3500 2400 300

Air temperature sensor:

°G

(FF)

ohms

O

(32)

6000

20

(68)

2400

CO at 3000 rpm (%) Bes

tele (Pelee

(between terminals) Injection duration checks Refer to Chapter 2

Injection waveform

Auto idle speed control valve

[Test terminals

Refer to test procedures

;

Small duration

Engine cold:

Throttle position switch/sensor

H. 2/199

42/200

Large duration

ms

%

{Test terminals

ohms

G12 & C1ls

3200 to

C1i2&C7

0 to 7200

(ECU)

degrees

.

|

Similar to, or above, idle values 3.5

4.35

262

ms

%

degrees

Thermotime

switch

7200

(Throttle closed to fully open)

Test terminals

Similar to, or above, idle values 23

ZF

Weds

Lute

3.66

2.19

eal

7.00

4.20

2.0

9,99

5:99

I:

ei)

a

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

Q3Ne'247/ (BStorBs) 1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP sensor

Test terminals

Refer to test procedures

Rover

HONDA

PGM.-FI

827Si, 827SLi, Sterling & Vitesse 88 to 89

13

1

10..4/5.-16 Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU (under driver's seat) Water temperature sensor DOaANDAARWBH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays (under driver's facia) 73 Cold start injector 14 Warm-up regulator 15 Vacuum/pressure switch 76 Fuel filter 17 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle contro/ valve PETITES

Not al/ items fitted to all models

H.19669

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

The engine is fitted with an automatic idle speed control, eliminating the need to adjust the idle as a service procedure. A basic setting is, however, achieved by observing the yellow LED display located on the ECU under the driver's seat. If the basic setting is incorrect, the LED will be flashing, or permanently on. Adjust the bypass screw ‘1’ on the throttle body until the LED goes out.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the control box, and remove the tamperproof plug. Using a suitable screwdriver, adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof plug after adjustment.

Honda

PGM-FIl

Contents

Injection signal and duration ..........c.:cccseeeteeeess Bi Sacha ae eas nrottie butterfly Setting IRs MA i ie sncLeaaviee, Gisele uae TRrottla POsiiOn-Sensor ...... WGA. BAe. deonecss peat icat cca my Fast idle valve (auxiliary air valve) ............ccceee Betis ck, ME tes Idle solenoid valves (4-cylinder engines) ....... TEA, 8: ae Automatic idle speed control V6 engines) ........ AGA octane ee TN etl) Toye] Re ne eee eee Saree er WOR, - Oe EL eth oe eer. 4.

Injection signal and duration General Wherever possible, it is advantageous to check for an injection signal and the duration as a first test. In many cases, this will provide a good indication of possible faults in the electrical/electronic operation of the system. Refer to Chapter 2 for instructions on how to check for injection signal and duration.

Dynamic checks To obtain an injection signal (unless the test equipment is supplied with an adapter), it is usually easiest to roll back the rubber protection boot on one of the injectors, and touch the test lead to each of the two terminals separately until a signal is obtained. Alternatively, gain access to the ECU terminals with the multi-plug still connected, and refer to the wiring diagram for the appropriate terminals to connect to, to obtain the injection signal. On an engine which will not start, always check the operation of the ignition system

364 364 364 365 365 366 on 367

Watermtemperature.sensOrierentarcrectciti ete eeticd gana meeseceses ana Ait temperature SONSOUibrte wciasaccs ciccas ocas 2 a eeer Reet ancy xtsccncs a ae UNTO CEG TS are cts,eee Sete etree tts tet ate ewautns gece men ENE sno 2 ea Fuel system pressure and fuel pump Checks ...............00ceeeeeeee FRG LalVsCHECKS ernroetednteaete. cteretcnaccusnciee tele vaenine Memeeees tris PRETIAUSWIEGI) Ere. eed teh«ac cicsinanieeawitee oii AME Deke oe ols see sna na ana ee ECU checks, fault diagnosis and wiring diagrams

first. The injection system relies on a signal from the ignition system, and will therefore not function if the ECU does not receive an ignition pulse. Check for an injection signal. If there is no signal available at all, refer to the injector checks. If an injection pulse is available, check the duration. If the engine is cold, and the pulse is too small, or if the engine is hot, and the pulse is too large, refer to the water temperature sensor checks. Also refer to the MAP and throttle position sensor checks. If the engine does run, again check the duration cold and hot, and if it is incorrect, refer to the checks as detailed above. If the engine is already hot, refer to the water temperature sensor checks for details of the water temperature simulation test. Check for an increase in the duration during a snap acceleration test, and if it is not acceptable, refer to the airflow meter checks. Also check for injection cut-off during deceleration (where used), and if it is not functioning, check the throttle position sensor. If the above checks appear to provide acceptable results, this generally indicates that the electrical system is satisfactory. If there still appears to be an injection system fault, carry out the fuel pressure checks before any detailed electrical component checks are carried out.

Throttle butterfly setting

H, 2/200 Injection

waveform

The throttle linkage and throttle butterfly are factory-set, and should not normally be adjusted. If it is necessary to check or adjust the butterfly closed position, the following procedure can be used. Slacken off the throttle linkage stop screw on the throttle body until there is a small air gap. Screw the stop screw in an additional half-turn. This should result in an air gap of approximately 0.05 to 0.15 mm (0.002 to 0.006 in) between the throttle butterfly and

367 367 368 368 370 370

H.21205

Throttle butterfly air gap (typical) the throttle casing. On vehicles that do not have an automatic idle speed control, with the idle bypass screw fully closed, the idle speed will typically be around 600 to 650 rom with the correct butterfly air gap. After setting the butterfly, check the operation of the throttle position switch or sensor.

Throttle

position sensor

General description The throttle position sensor indicates to the ECU the position of the throttle butterfly, and any change in its position. Also noted by the ECU is the rate at which any change in throttle position occurs. The sensor is of the variable resistance type, which provides a varying voltage output to the ECU as the throttle position changes.

Dynamic checks Run

the

engine

at

normal

temperature,

and quickly snap open the throttle. As the throttle is released, the injector ticking should momentarily disappear until the engine speed drops below around 1500 rpm — the injectors should then be heard to start operating again. If the injectors are not cutting off during this test, it indicates a

Honda

throttle sensor fault, or incorrect basic adjustment of the throttle butterfly. If it is difficult to hear the operation of the injectors, carry out the same test, but check the injection signal or duration using test equipment as detailed in the injection signal and duration checks Section. The signal should be seen to disappear as the throttle is released, and then return when the engine speed drops. If it is apparent that the injection is not being cut off when the throttle is released, carry out the static checks.

365

PGM-FIl

engine coolant is cold. The valve opens when the engine is cold, and as the coolant temperature rises, a wax-filled thermostat expands, thus closing the valve. When the valve is open, additional air is allowed to bypass the throttle butterfly and provide the fast idle.

Note: /t is also likely that if the throttle switch is not indicating idle, the idle speed control! valve will not be functioning correctly, which will result in a fast or erratic idle.

standard idle setting and the coolant temperature-sensitive fast idle.valve. The solenoid

valves are normally

located

in the

control box, and are connected to the inlet manifold via vacuum pipes. When the valves are open, air is drawn from the independent filter, through the valve to the engine, thus providing an increase in the idle speed. The valves may function due to increased electrical load on the engine at idle, so that the original idle speed is maintained, or during engine warm-up. On some applications where automatic transmission is fitted, an additional valve is fitted to prevent the engine from stalling. A valve may also be fitted on vehicles equipped with air conditioning, to prevent reduced idle when the air conditioning is operating.

Idle speed adjustment When adjusting the idle speed, to ensure that the idle control valves are not affecting the idle speed, clamp vacuum hose 10 to

H.2/293

Throttle position sensor

Static checks With the engine running and the sensor plug connected, check for a supply of around 5 volts at one of the three terminals on the connector plug (it will be necessary to use a thin probe to gain access to the terminals). If the voltage is not available, refer to the wiring diagram, and check the wiring through to the ECU. Check on one of the remaining terminals for a voltage reading that increase as the throttle is opened. The voltage should be around 0.5 volts at idle, and approximately 4.5 volts at full throttle. If the voltage does not alter, check the resistances of the throttle sensor. Disconnect the throttle position sensor plug, which is located a few inches from the sensor. Refer to the Specifications and note the resistance of the sensor. Also check the resistance between either of the two side terminals and the centre terminal. Slowly open the throttle, and check for a progressive increase or decrease in resistance. If there is an open-circuit reading between the closed and open positions, it indicates a faulty sensor.

thermostat is faulty — the valve should then be renewed. If the idle remains fast after the engine is warm, remove the cover from the top of the fast idle valve, and examine to see if the valve is fully closed. Check by placing a finger over the area of the valve seating, and if any suction exists, it indicates that the valve is leaking.

Fast idle valve)

Idle solenoid engines)

valve

(auxiliary

air

H2/294

H.2/295 Fast idle valve

Idle speed control solenoid valve (located in control box)

Static checks lf, when the engine is cold, there is no fast idle, the valve assembly should be removed from the engine. Run cold water through the water pipes of the valve, and blow through the air ports to check that the valve is open. If water does not easily flow through, clean the valve with a suitable solvent. If the valve does not appear to be opening and allowing air to pass through, cleaning may effect

a cure,

but

it is likely that the wax

valves

(4-cylinder

General description

General description

The fast idle valve, located on the throttle body, is used to provide a fast idle when the

A number of solenoid valves are used on the PGM-Fi system, to supplement the

H.21296 Idle speed

control solenoid conditioning)

valve

(air

366

Honda

PGM-FI

prevent additional air passing to the intake

Dynamic checks

system from the valves. lf the vehicle is equipped

The valve operation can be checked by running the engine at normal operating temperature, and applying load to the engine at idle speed. Where fitted, switch on the air conditioning, or if fitted with automatic transmission, place it in ‘Drive’. Al-

with air condi-

tioning, there is provision on the air conditioning

idle control

valve

for adjusting

the

fast idle when the air conditioning is operating. After initially setting the basic idle speed, switch on the air conditioning, and adjust the screw until the standard idle

ternatively,

speed is maintained. Also check on automa-

tic transmission vehicles that the idle speed is maintained when the transmission is ‘in Drive.’

on

the heated

rear win-

Static checks

Static checks lf it is suspected that an idle control valve

is not functioning, gain access to the control box. Follow the vacuum pipes from the intake system, and locate the pipe marked number 10. The number 10 pipe is used to supply air from the idle control solenoid valve, and where fitted, the fast idle control solenoid valve. Locate and disconnect the electrical connections to the valve to be tested. Momentarily supply an independent live and earth connection to the valve. The valve should be heard to operate, but if not, reverse the connections and re-check. If the valve appears not to function, it should be renewed. During the test, disconnect the connection to vacuum pipe 10, and apply vacuum to the valve. When the solenoid operates, the valve should be open, allowing air to flow through. When the electrical supply is disconnected, the valve should be closed, preventing airflow. If the valve is not operating correctly, it should be cleaned or renewed. On vehicles with idle control valves triggered by the automatic transmission, apply the same test procedures, but note that the relevant vacuum hose is number 23.

Locate the idle control valve, adjacent to the throttle body. Check with the engine running and the electrical plug connected

H.21297

that there is voltage available at both the terminals of the plug (it may be necessary to use a thin probe to gain access to the terminals or wires). If there is only voltage at one wire, switch

1

>

SS

“RY H.19669

Auto idle speed control

Automatic idle (V6 engines)

speed

controls [dle speed adjustment

General description The V6 engines use two idle speed control valves. A fast idle control valve is used as an auxiliary air valve during cold engine operation. It is identical

switch

dow or the headlights. The idle speed should be maintained at the specified valve by the idle speed control valve. If the valve appears not to be working, carry out the following checks.

in operation to the type

fitted to the 4-cylinder engines — refer to the fast idle valve (auxiliary air valve) Section for test procedures. A second idle speed control valve is fitted, to overcome the reduction in idle speed when additional load is applied to the engine. The valve compensates for electrical

load, air conditioning operation automatic transmission drag.

and

To set the idle adjuster to its correct position, it is necessary to observe the yellow LED on the ECU. Ensure that the engine is at normal operating temperature, and that no additional load is applied, for example, electrical load, air conditioning or power steering. If the LED is off, no adjustment is necessary. If the LED is flashing, the adjuster screw should be turned clockwise. If the LED is permanently on, the screw should be turned anti-clockwise. Turn the screw a quarter-turn at each adjustment, and allow time for the LED to change its signal.

off the engine, disconnect the plug, and check for a resistance across the control valve terminals. If the reading is opencircuit, renew the valve. If the resistance is satisfactory, check the wiring through to the ECU terminal A11 on 2.5 litre engines, and B13 on 2.7 litre engines. If the connection is good, remove the valve and clean or renew it, but also refer to the ECU checks. If there is no voltage at either terminal, check for continuity of the wiring through to the control relay terminal 3. If the wiring is satisfactory, refer to the relay checks.

MAP

sensor

General description The MAP (manifold absolute pressure) sensor is used to detect engine manifold vacuum or pressure, which is an indication of load. In most applications, the sensor is located in the control box, but some of the 4-cylinder vehicles have the sensor located on the bulkhead (refer to the vehicle under-bonnet layout).

Dynamic checks Locate the sensor, and using a fine probe, gain access to the three wires or terminals of the connector plug. With the engine running, check for a supply voltage of approximately 5 volts to one of the wires. If there is no voltage, check the wiring through to the ECU (refer to the wiring diagram). Check on one of the remaining wires for a varying voltage as the throttle is snapped open and closed. The voltage should vary between approximately 0.5 and 4.5 volts. If the voltage does not change, continue with the next check.

Honda

ignition on or the engine running. If there is no voltage, check the wiring through to the ECU. On one of the remaining wires, check for a voltage of typically 2.5 to 3 volts. Changes in air pressure will affect the reading, but a reading between 0.5 and 4.5 volts is acceptable. If the reading is incorrect, the sensor is likely to be faulty, but check the wiring through to the ECU.

Water temperature

sensor

General description The water temperature sensor provides a varying voltage signal to the ECU, to indicate engine coolant temperature. This enables mixture correction to take place, in response to engine temperature changes.

H.21298/99 MAP

sensor

Disconnect the vacuum hose to the sensor, and using a vacuum pump or a piece of rubber pipe connected to the sensor, suck on the pipe. With the ignition on, the voltage should change. If the voltage does not alter, check the wiring through to the ECU, but it is likely that the sensor is at fault. If the voltage now changes, but not when connected to the engine vacuum pipe, check the pipe for leaks or blockages.

Atmospheric air pressure sensor General description The atmospheric air pressure sensor Is used to supply information regarding air pressure. Changes in air pressure require alterations to the fuel mixture. The ECU responds to the air pressure sensor voltage signal, and alters the mixture to suit.

367

PGM-FI

H. 2/30] Water temperature sensor

Dynamic checks Carry out an injection duration check, and refer to the specified readings. Checking the duration on a cold engine should provide a large duration, which should reduce as the engine warms up. If the engine will not start, the duration can be checked during cranking, but note that the first few moments may provide a higher duration reading than specified. During cranking or running, a substantially smaller than specified duration when cold, or a substantially larger duration when hot, indicates a probable sensor or sensor circuit fault, but refer to the water temperature simulation test.

Water temperature simulation test With the engine switched off, pull off the connector plug from the water temperature sensor, and bridge the connector plug

terminals with a suitable piece of wire, or preferably a resistor of approximately 200 to 300 ohms — this will provide a hot engine simulation. Crank, and if possible start, the engine (run at 1500 rpm), and note the injection duration, which should be close to the specified reading for a warm engine. Switch the ignition off, and remove the bridging wire or resistor. Either leave the plug terminals unconnected, or preferably bridge with a resistor of approximately 6 K ohms or more, to simulate a cold engine. This simulation can cause extreme flooding of the engine, preventing starting. Repeat the test, which should now provide a noticeably larger duration than during the hot-engine simulation. The duration reading should be close to, or greater than, the specified value for a cold engine. If the engine fails to start due to flooding, this indicates correct ECU response. If, during the simulation tests, there is no noticeable difference in duration measurements, check the sensor plug and wiring for continuity to the ECU terminal and to earth (refer to the wiring diagram). If there is no wiring fault, suspect the ECU.

Air temperature sensor General description The air temperature sensor operates in much the same way as the water temperature sensor, but indicates to the ECU the temperature of the air being drawn into the engine. The effect of the sensor is not as great as that of the water temperature sensor, and dynamic checks are not so conclusive.

owe

Static checks

H. 2/300 Air pressure sensor

|

Static checks Using a thin probe, check for a voltage reading of approximately 5 volts to one of the sensor wires or terminals, with the

Pull off the sensor connector plug, and measure the resistance across the sensor terminals, comparing the readings against those specified. If the sensor is not removed from the engine, it is advisable to take measurements with the engine cold, and then with it hot, to establish the change in resistance in conjunction with the change in temperature. The sensor can, however, be removed and tested in water at various temperatures. If the sensor resistances are correct, check the connections and continuity of the wiring from the two sensor plug terminals to the ECU and earth (refer to the wiring diagram).

H.21302

Air temperature sensor

Static checks With the plug connected to the sensor, using a thin probe, check the voltage at the two wires or terminals of the plug with the

368

Honda

PGM-FI

engine running. A supply voltage of approximately 5 volts should be measured on one terminal, and the remaining terminal

and if correct, carry out the static injector checks. If there is no injection signal, check

should provide a reading of typically 2 to 3 volts. Note that the voltage will depend on the ambient air temperature. If there is no supply voltage, check the wiring through to the ECU. If there is supply voltage but no sensor output voltage, carry out the next check.

and if necessary from the control relay to the resistors. Refer to the relay checks Section if

Disconnect

the plug from the sensor, and

check the resistance across the two sensor terminals, and compare with the specified value. A tolerance should be allowed, depending on the exact temperature. A faulty sensor is likely to be indicated by an open-circuit reading. If the reading is incorrect, replace the sensor.

for supply voltage from the power

the

relay

is not

supplying

resistors,

voltage

to

the

resistors, Or renew any faulty resistors if necessary. Check the continuity of the wiring from the injector plugs to the ECU multi-plug connector — disconnect all other system connector plugs, and refer to the wiring diagram. If the injection signal exists, but the duration appears to be incorrect, or if supply voltage is correct, and there is still no injection signal, refer to the ECU checks for a guide to further tests.

Bridging a relay with a 20A fuse

Static checks

Injectors General description The injectors receive a live feed from the control relay, via a set of ballast or power resistors (one for each injector). The injectors are switched on and off on the earth circuit, via independent connections through the ECU.

Remove the connector plug from the injector(s), and check the resistance across the two injector terminals, comparing with the reading specified. Also ensure that there is no continuity between the injector body and the injector terminals, Note: /f there is no fault found during the above checks, but it is apparent that one or more injectors are not functioning correctly, it is probable that fouling exists in the faulty injectors, and a flow rate test may be required — refer to Chapter 2.

Fuel system

pressure

and fuel

pump checks Fuel pump relay — bypassing

AH. 21202

Connection to an injector

Dynamic checks Crank or run the engine, and listen to each injector for a clicking sound as the injector Operates

(it may

be

necessary

to

use

a

suitable listening device, such as a screwdriver, as a ‘stethoscope’). If it appears that one or more injectors are

not functioning, carry out the following checks. Check the injection signal and duration,

H 21207

For a number of the following tests, it is necessary to crank the engine in order to allow the pump to run. It is possible to bypass the pump relay, which will allow the pump to run without cranking. Locate the control relay, which also acts as the pump relay. Remove the relay, and locate the terminal on the relay holder that is permanently live. Bridge the live terminal to the fuel pump wire, which will then run the pump. The bridging wire should be fitted with a 20 amp fuse to protect against a possible short-circuit. Due to the variations that exist in the wiring colours, it will be necessary to check for continuity between the relay holder terminals and the fuel pump, to establish which of the relay terminals connects to the pump. If necessary, it is possible to provide an alternative live feed to the pump, but ensure that a 20 amp fuse is used, and that there is no possibilty of sparks occurring near petrol.

Fuel system pressure checks The system should provide fuel to the fuel

rail and injectors, at a pressure which is constant in relation to manifold pressure. The system consists of a pump, main filter, fuel rail (to distribute the fuel to the injectors) and injectors, which contain a fine filter. To maintain the pressure, a pressure regulator is fitted, which allows excess fuel back to the tank. The regulator is connected to the inlet manifold via a vacuum pipe, in order to adjust the fuel pressure in conjunction with changes in the manifold pressure. Warning: Before disconnecting any of the fuel lines, it is advisable to disable the fuel pump and run the engine, to depressurise the fuel system. The fuel pump relay is incorporated in the system relay, preventing the pump supply from being disconnected without disabling the rest of the injection system. It is therefore necessary to independently disconnect the fuel pump electrical connections directly at the pump. Disable the fuel pump and run the engine until it stops, to depressurise the fuel system. Connect the fuel pressure gauge as indicated in equipment manufacturer's instructions, and connect the gauge either at the fuel inlet connection to the fuel rail, or between the fuel rail and the pressure regulator. Wherever possible, locate a tap between the gauge and the fuel rail. Reconnect the fuel pump, and start the engine (make sure that if a tap is fitted with the gauge, it is in the ‘open’ position). If the engine will not start, crank the engine or bypass the relay, which will allow the pump to operate and provide the required pressure. Note the fuel pressure. Disconnect the vacuum pipe at the fuel pressure regulator, and plug the hole in the pipe. The fuel pressure should increase to the specified value. (During cranking, the engine only produces a low vacuum level, therefore the

Honda

369

PGM-FI

Fuel pump

PRESSURE REGULATOR EXCESS FUEL RETURN

FUEL

RAIL

INJECTOR

FUEL TANK FUEL PUMP Fuel system

fuel pressure will be very close to the specified level even if the vacuum pipe remains connected.) Also note that on an engine which is

running, the same test can be carried out using a CO reading, which should increase in conjunction with the fuel pressure increases. Note: A/though the system pressure may be correct when the engine is running under workshop test conditions, it does not prove that the pressure and fuel flow are acceptable at high engine speeds and /oads. Unless the pressure can be checked with the vehicle on a rolling road, it will be necessary to carry out fuel pump checks to establish whether the pump can supply sufficient fue/ at the required pressure when the fuel demand is high. With the engine running, if the fuel pressure is already at the specified level prior to disconnecting the regulator vacuum pipe, the pressure regulator is likely to be faulty, but ensure that manifold vacuum is available from the vacuum pipe, and that there are no leaks. lf the fuel pressure is higher than specified, it indicates a faulty pressure regulator, but it is possible for a blockage on the return line from the regulator to cause a high system pressure. _ Attach an independent pipe to the pressure regulator on the return pipe connection, run the engine, and allow the fuel to drain into a suitable container. If the fuel pressure is now at the specified level, check the

and filter checks

The fuel pump is able to provide the system with a greater quantity of fuel than is required to run the engine. The excess fuel is

vehicle return line for a blockage. If the pressure is still high, renew the regulator. If the fuel pressure is lower than specified, it is possible that the regulator is faulty, but the most likely cause is a faulty fuel pump, or a severe blockage in the fuel filter or supply line. Where possible, with the engine running or cranking, briefly clamp the fuel return line from the regulator. If the pressure now rises substantially, it indicates a regulator fault. If the pressure remains low, carry out fuel pump checks, and also look for a fuel leak between the pump and the regulator.

passed back to the tank via the fuel pressure regulator. The fuel passes from the pump through a main filter before reaching the fuel rail and injectors. The electrical supply for the pump originates at the relay, and it will only switch on the pump under certain conditions. Crank the engine, and listen for pump operation. If the pump is not running, check for supply voltage to one of the connections at the pump by repeating the cranking test. If the supply voltage is not available, check the wiring through to the relay (refer to the wiring diagram), and carry out relay checks if necessary. Check for a good earth on the remaining connection at the pump, and rectify if necessary. If the electrical connections and supply voltage are good, but the pump will not run, it should be renewed. When carrying out system pressure checks, if the pressure is low, or if it is suspected that the pump is failing when the fuel demand is high, it will be necessary to carry out a flow rate and maximum-pressure check. If a pressure gauge and tap can be connected to the system (refer to the first fuel system pressure check), turn the tap to the ‘off’ position, and crank the engine until a maximum pressure reading is reached. The pressure should reach approximately 5 bar (75 Ibf/in?)

or more.

If the pressure

is too

low, it indicates a pump fault. It is unlikely that a filter blockage will prevent the pressure from reaching the required level, unless the blockage is very severe.

FUEL RAIL

RUEL SUPPLY

H.21209

Connecting

a pressure gauge

370

Honda

lf the maximum pressure is acceptable, it is still advisable to carry out a flow rate check.

Disconnect

CONTROL

PGM-FI

BOX

PRESSURE REGULATOR VACUUM CONTROL

the fuel supply line from

the fuel rail, and allow the fuel to drain into a suitable container. The test should ideally be

carried out for a period of at least thirty seconds. It will therefore be advisable to bypass

the

fuel

pump

relay

to

allow

the

pump to run without cranking the engine (refer to ‘fuel pump relay — bypassing’). Run the pump, and note the fuel quantity delivered, comparing with the specified value. A low output would indicate a probable pump fault, but a check should be made for blockages in the lines and the filter, as detailed in the following paragraph. Disconnect the fuel supply line from the filter, and repeat the fuel flow rate test by running the fuel directly from the pump to the container. If the flow rate is now close to that specified, renew the filter. Hf. 2/303

Vacuum

Relay checks General description The control relay is used to provide a switched voltage supply to the injection system components. The relay requires certain items of electrical information before it will switch the system on. The injectors, fuel pump and ECU receive a voltage supply via the relay.

AH.2/204

Pressure regulator

Special notes

Static checks

Note that on most models, the vacuum pipe to the fuel pressure regulator is connected to a cut-off valve. The valve prevents manifold vacuum affecting the regulator

Note: Aefer to the wiring diagram carrying out the following checks.

when

the coolant

or air temperature

is too

high. The pressure regulator then ensures a high fuel pressure, to reduce the chance of fuel vapourisation. If when testing the fuel system, the water temperature is likely to be higher than around 100°C (212°F), or the intake air temperature higher than approximately 80°C (176°F), a higher fuel pressure will be measured, and there will be no change in the pressure or the CO reading when the vacuum

pipe

is

disconnected

from

the

regulator. It is advisable to check that the valve is functioning

at

normal

temperatures,

checking that manifold vacuum the regulator.

by

is reaching

when

If, when carrying out the component checks, it is found that there is no supply voltage available from the relay, check for continuity of the wiring from the component to the relay, and rectify if necessary. Remove the relay from the holder and connector plug. Apply voltage to relay terminals 5 (positive) and 2 (negative) — the relay should be heard to operate, which should connect terminals 1 and 3. Check for continuity across 1 and 3, and if there is no continuity, renew the relay. Repeat the test by applying voltage to terminals 4 (positive) and 8 (negative) and check for continuity across terminals 5 and 7. Note: /f the relay checks are not conclusive, or if the terminals are not marked, use the following alternative checks.

control

valve

Remove the relay from the holder, and check for a permanent live feed with the ignition off, to one of the relay plug terminals (usually terminal 1). If there is no supply voltage, trace the wiring through the fuse to the battery. Check for a supply voltage to one of the terminals when the ignition is switched on (usually terminal 5), and if unavailable, check the wiring through to the ignition switch. Also check for an additional feed from the switch to the relay (usually terminal 4) during cranking. Check for an earth connection to one of the terminals (usually terminal 2) and a connection to the ECU (usually terminal 8), which is an earth controlled by the ECU. If all the wiring connections are satisfactory, renew the relay.

Inertia switch

General description An inertia switch is fitted on some vehicles, which will cut off the electrical supply to the fuel pump, and possibly other components, in the event of an accident.

Static checks If it is apparent that there is no live feed to the pump or other components, locate the inertia switch, and check for continuity between the two terminals. If the switch is

Honda

Main

371

PGM.-FI

control

relay

O)

Live feed to fuel pump

OC) Terminal

O

A12

ECU

Earth connection Live feed to injector resistors, idle speed control valves, terminal A15 ECU

H. 2/2 16 Typical

inertia

O) Live feed from starter circuit (fused 10 amp)

etch

O) Live feed from ignition on (fused/10 amp) O) Live feed battery +ve (fused)

open

(no continuity),

operate

the reset

button. If the switch is still open, renew it.

H 21308 a

f

Relay wiring diagram

ECU

checks — Honda

PGM-FI

General It is not possible, without dedicated test equipment, to carry out a direct check on the ECU. It is, however, possible to establish whether or not. the ECU is functioning by carrying out the following tests. The tests are divided into two categories — one with the ECU multi-plug connected, and one with the multi-plug disconnected. It should be possible with these tests to establish that all the

ECU multi-plug terminal

Multi-plug connected (Yes/No)

Test to be carried out

Al A3 A5 A6 A7 A11 A13 A15 A17 B13 B20 C5 C6 Cy C9 C11 C15

Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes

Check Check Check Check Check Check Check Check Check Check Check Check Check Check Check Check Check

connection connection connection connection connection connection connection connection connection connection connection connection connection connection connection connection connection

A2 A4 A16 A18 B17 C12 C13 C14

No No No No No No No No

Earth Earth Earth Earth Check Check Check Check

connection connection connection connection connection connection connection connection

and and and and and and and and and and and and and and and and and

to to to to

connections to the system components are satisfactory, and the relevant signals are being passed from the sensors to the the ECU is still not providing the correct output signals injectors, then the ECU should be substituted. Warning: Do not disconnect the ECU multi-plug with the switched on.

that all ECU. If to the ignition

signal to injector no 1 during cranking, or when running signal to injector no 2 during cranking, or when running signal to injector no 3 during cranking, or when running signal to injector no 6 during cranking, or when running signal to injector no 4 during cranking, or when running signal to idle control valve (EICV) during cranking, or when running signal to injector no 5 during cranking, or when running voltage from main relay terminal 3 during cranking, or when running voltage from battery positive during cranking, or when running (fused 10A) voltage from starter circuit during cranking, or when running voltage from idle mixture adjuster during cranking, or when running voltage from air temperature sensor during cranking, or when running voltage from water temperature sensor during cranking, or when running voltage from throttle position sensor during cranking, or when running voltage from air pressure sensor during cranking, or when running voltage from MAP sensor during cranking, or when running voltage to MAP sensor during cranking, or when running

auxiliary air valve air pressure sensor air pressure sensor MAP sensor

373

Fault diagnosis —- Honda

PGM-FI

Test components in the order given alongside specific faults

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Unstable idle

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Excessive fuel

7

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374

Honda

PGM-FI

Injection

C5

C6

Air temperature sensor

Water temperature sensor

B20

ECU

Ci

Idle mixture adjuster

Throttle position sensor

CiZICoMCIs

PA sensor

C142 CiINCi5

MAP

sensor

H. 21305

Honda

PGM.-Fi wiring diagram

Injection ECU

O Terminal 3 Main

Cylinder

1

Cylinder 2.

Cylinder 3.

Cylinder 4

Cylinder5

Cylinder 6

Injector resistors

H.2/306

Honda

PGM-Fi

wiring diagram

relay

Honda

375

PGM-FI

Injection ECU

Ai3__A15

Ignition switch ©) Terminal 3 Main relay

Pressure regulator cut-off

Honda

16

43. 11

9

7

(=t=[-T=T=

T=]

Auxiliary air valve

EICV H.21307

PGM.-Fi wiring diagram

UAE TE

T

3 A

[=[=T=l=[=[=[=1=[=[=}2f=1=

ISas 16 14 12 10 8 6 4 2/20 18 16 41210 8 6 4 2/18 16 14 1210

ECU

terminals

Sa 8 6 4 2

376

LUCAS

Austin Rover Montego 2.0 EFi, MG

Montego 2.0i

& MG

HOT WIRE

(LH)

Refer also to page 39

Maestro 2.0i/EFi 84 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT =Auto

N/A

= Not available/applicable

™* = Throttle closed

+ = Throttle open

Static checks

Dynamic checks

Resistance characteristics

Basic checks Idle speed (rpm)

735 + 50N 750 + 50 N (1989)

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

1 to 1.5 (Pre 1985)

Water temperature sensor:

2.0 to 2.5 (1985 on)

CO at 3000 rpm (%)

10.0

HC at idle (ppm)

=< 1250

Air temperature sensor:

15 to 20

(°F)

10 (50) 20 (68) 80 (176) 2G

(°F)

(Combined with Airflow meter)

Injection duration checks Refer to Chapter 2 Injection waveform

Auto idle speed control valve

Test terminals

ohms

15 & 3(ECU)

45 to 55

14 & 2(ECU)

45 to 55

ohms

4.21200 Small duration

Engine cold:

9 & 22(ECU) 9 & 12(ECU)

“if Large duration L 2/199

ms

%

degrees

ms

4.27

%

degrees

5000

Ree” H2/447

Similar to, or above, idle values

4.72

500 to 50600

Thermotime

switch

Test terminals

Similar to, or above, idle values

3.0

2.65

3.83

3.44

7 ee

ooo

10.50

9.45

EZa)

>18

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min) ....

2.5 (36) or 3 (43) with ECU mod. 1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP

sensor

Test terminals

Refer to test procedures

Austin Rover Montego

2.0 EFi, MG

LUCAS Montego

2.0i

& MG

Maestro

HOT WIRE

(LH)

2.0i/EFi 84 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed contro! valve

/njectors Thermotime switch ECU (Maestro: under passenger ANDAARWBH™ seat. Montego: under glove compartment) 9 Water temperature sensor 70 Air temperature sensor 77 Pressure regulator 72 Relays 13 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter 17 Metering head 78 /njector resistors 19 Load enrichment device 20 Additional idle control valve Not all items fitted to all models H. 2/005

Idle speed and CO (mixture) adjustment 1 2

Idle speed adjustment ~The vehicle is fitted with an automatic idle speed control, eliminating the need to adjust the idle as a service procedure. Earlier vehicles had an idle bypass adjuster ‘1’ which is used to obtain a basic setting (refer to the idle speed control test procedure for a basic setting). Later vehicles had the bypass adjuster deleted.

Idle bypass adjuster screw CO (mixture) adjuster screw

CO (mixture) adjustment Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the throttle body, and remove the tamperproof plug (where fitted). Using a suitable screwdriver, screw in the adjuster to increase the CO level, or unscrew the adjuster to reduce the CO level. Set the CO reading to the specified level, and fit a new tamperproof plug.

378

Rover

LUCAS

HOT WIRE

(LH)

Refer also to page 39

216 Efi 85 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A = Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks Resistance characteristics

Basic checks 710+ 50N

Idle speed (rpm)

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

15 to 20

Water temperature sensor:

(°F)

10) ¢(50) 20 (68) 80 (176) CO at 3000 rpm (%) Ei Giles D0)

Air temperature sensor:

Injection duration checks

Airflow meter)

[GC

(°F)

(Combined with Refer to Chapter 2 Injection waveform

Auto idle speed control valve 5

Test terminals

ohms

15&3

45 to 55

1442

45 to 55

Test terminals

ohms

14

H. 2/199

4. 2/200

Small duration

9&

Large duration

22

9&12

Engine cold:

ms

%

degrees

a”

cp

4.72

4.27

ms

%

degrees

5000

a,

H2/447

Similar to, or above, idle values 3.8

500 to 5000

Thermotime

switch

Test terminals

Similar to, or above, idle values

2.4

3.0

2:05

1000 rpm

253

3.83

3.44

2000 rpm

Pet

ToS

6.59

3000 rpm

2a

10.50

9.45

S20

>318

Snap open throttle

Fuel system checks Fuel pressure - regulator vacuum

pipe

disconnected - bar (Ibf/in2)

2.5 (36) nominal

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

Airflow meter/ MAP sensor

Test terminals

ohms

Refer to test procedures

Rover

LUCAS

HOT WIRE

(LH)

216 Efi 85 to 89

11

21 5

2

1/10 Airflow sensor

MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve

Injectors Thermotime switch ECU (under passenger seat) Water temperature sensor DANDAARWNH™ 70 Air temperature sensor

77. 72 13 714

Pressure regulator Relays Cold start injector Warm-up regulator

75

Vacuum/pressure

16 17 18 19 20

Fuel filter (at rear of vehicle) Metering head /njector resistors Load enrichment device Additional idle contro! valve

switch

Not all items fitted to all models

Idle speed and CO (mixture) adjustment 7 2

Idle speed adjustment ~The vehicle is fitted with an automatic idle speed control, eliminating the need to adjust the idle as a service procedure. Earlier vehicles had an idle bypass adjuster ‘1’ which is used to obtain a basic setting (refer to the idle speed control test procedure for a basic setting). Later vehicles had the bypass adjuster deleted.

Idle bypass adjuster screw CO (mixture) adjuster screw

CO (mixture) adjustment Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the throttle body, and remove the tamperproof plug (where fitted). Using a suitable screwdriver, screw in the adjuster to increase the CO level, or unscrew the adjuster to reduce the CO level. Set the CO reading to the specified level, and fit a new tamperproof plug.

380

LUCAS

Rover

HOT WIRE

(LH)

Refer also to page 39

820i & Si 86 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

t = Throttle open

* = Throttle closed

Dynamic checks

Static checks Resistance characteristics

Basic checks

750 + 25MN 700 + 25ATN

Idle speed (rpm)

15 to 20

Injectors (ohms)

Cold start injector (ohms) Auxiliary air valve (ohms) Water temperature sensor:

CO at idle (%)

(°F)

10 (50) 20 (68) 80 (176)

CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

°C (°F)

(Combined with

Airflow meter)

Injection duration checks Refer to Chapter 2 Injection waveform

Auto idle speed control valve

Test terminals

ohms

15&3

45 to 55

1442

45 to 55

ohms H.21/199

42/200

Small duration

Engine cold:

500 to 5000

Large duration

ms

%

5000 degrees

LS H2/447

Similar to, or above, idle values

3.8

4.72

4.27

ms

%

degrees

Thermotime

switch

Test terminals

Similar to, or above, idle values

2.4

3.0

2D

23

Sibe

3.44

222.

Tees:

6.59

10.50

9.45

2 20

> 18

2A

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min)....

3 (44) nominal 1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP

sensor

Test terminals

ohms

Refer to test procedures

Rover

LUCAS

HOT WIRE

(LH)

820i & Si 86 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve Idle speed control valve /njectors Thermotime switch ECU (under driver's seat) Water temperature sensor DOANDARWH™ 70 Air temperature sensor 77 Pressure regulator 72 Relays (under facia) 73 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H.19295

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

2

CO (mixture) adjuster screw

Ensure the engine is at normal

The engine is fitted with an automatic idle speed control, eliminating the need to adjust the idle as a service procedure. A basic

setting is achieved by adjusting the throttle linkage, but refer to the idle speed control valve test procedure.

operating temperature,

and run it at

approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the throttle body, and remove the tamperproof plug (where fitted). Using a suitable screwdriver, screw in the adjuster to increase the CO level, or

unscrew the adjuster to reduce the CO level. Set the CO reading to the

specified level, and fit a new tamperproof plug.

Lucas Hot Wire (LH) Contents

Injection signal and duration .............cceeeeees Sere aay

eee {crsmentite. ceeteeit decateracsSeer heme & CF Seo THrOttle: POSIthOMPSEMSONPms este eeet eet eee eee A Me. SE (dlerspeed Control),

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3

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7

a

6

«..c.c.c.cececceseeereees

7

4—-6-+—3

...........c:eeeee

Unstable idle

eee ..............cceeeeee

wencsceveresesscrcesans

High CO at idle (adjuster ec ascivseeete sess. [IGT IOCTIVG ) aictecun Low CO at idle (adjuster

sien be Matsss

5

1

4

2

7

3

y.

7

7

2

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7

4

2

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...........:.:006

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wo

a.

Zi

oo oi

Excessive fuel COMSUIMIDEION

sg2

6

EOSs Of POWEF

BPE LOO ASUS

= D

©

7

Poor hot starting

acceleratiOn.

Ee NS 7 8.

..............

Poor cold starting

Flat spot under

bo j>

8&:

|2

Penwlomenbwitite (b) = ® re) 1SSeOP AS oe Engine will not start

oO

toy

cli OUP

————a

—

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5

i

J

5

4

5

4

S!

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ib

6

4

a

3

3

80

404

Lucas

LH Engine

Management

Injection ECU

©

Terminal Main

Water temperature

Throttle sensor

Airflow meter

87

control relay

H. 21382

sensor

Lucas LH Engine Management

wiring

diagram

Injection ECU

©

Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4

Cylinder 5

Cylinder 6

Injectors

Lucas LH Engine Management

H. 21383

wiring

diagram

Terminal 87 Fuel pump relay

Lucas

LH Engine

405

Management

Injection ECU

‘Gana |i) beth s\aalemnmassad ©tl ada iSmame

WG) 3|«lll alimentaire emma i¥ eae

samaeacemeearensamtda

Terminal 87 Main control relay Q

Earth connection

through body

are

linerice

Idle speed control valve

A]

6.8 ohm

Auxiliary air

resistor

valve

Lambda sensor ppeovaae:

Lucas LH Engine Management

wiring

diagram

1099 8 a7 6 5 4 3 2-4 Bow (=[=[=-[=-l=-[=-l=[=-[=[=l/=[=[=| YELLOW PLUG Z5iv2heeeeots

Ly

is12)

Ve

Ms

22ieeczineezo,

PAE

10»

29

8

AS

7

6

ECU

19

18

17.

Vr

ise

ee

ieee

3

terminals

16

2

1514

BLACK PLUG 1

406

LUCAS

Jaguar/Daimler XJ-S,

Refer also to page 39

P DIGITAL

SC & Cabriolet 3.6 83 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

+ = Throttle open

* = Throttle closed

Dynamic checks

Static checks Resistance characteristics

Basic checks Idle speed (rpm)

LOCO

Injectors (ohms)

800 + 50 (XJ-S/SC up to ‘88)

Cold start injector (ohms) Auxiliary air valve (ohms)

Water temperature sensor:

CO at idle (%) 1 to 2 (XJ-S/SC up to ‘88)

(between terminals)

PCA

Fr)

102

(50)

20 (68) 80 (176) CO at 3000 rpm (%) pe

Air temperature sensor:

etPE

(between terminals)

°C

(°F)

O74 (32)

20 (68)

Injection duration checks Refer to Chapter 2

Injection waveform

Auto idle speed control valve

_—‘|Test terminals

Throttle position switch/sensor

|Test terminals

H. 2/199

H.2/200

Small duration

Large duration Refer to test procedures

Engine cold:

ms

%

degrees

Similar to, or above, idle values 35

4.64

2.8

ms

%

degrees

Thermotime switch

W & Switch Body < 30°C/86°F

Similar to, or above, idle values 233

3.0

1.60

2.2

3.66

Zio

2a

7.00

4.20

9.39

5.99

> 20

otZ

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal 1.5 to 2 (2.6 to 3.5)

Test terminals

ohms

0 to 10

:

Airflow meter/MAP sensor

Test terminals

Refer to test procedures

Jaguar/Daimler

LUCAS

P DIGITAL

XJ-S, SC & Cabriolet 3.6 83 to 89

Airflow sensor MAP sensor (in ECU) Throttle position switch/sensor Auxiliary air valve /dle speed control! valve Injectors Thermotime switch ECU (in luggage compartment) Water temperature sensor DOANDARWNH™ 70 Air temperature sensor 771 Pressure regulator 72 Relays 73 Cold start injector 74 Warm-up regulator 75 Vacuum/pressure switch 716 Fuel filter (in luggage compartment) 17 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H,19472

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

Run the engine until it is at normal operating temperature. Locate the idle screw ‘1’, and adjust to achieve the specified idle speed.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the ECU, which is located in the vehicle boot, Remove the tamperproof plug, and adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof plug after adjustment.

408

Jaguar/Daimler

LUCAS

XJ-S V12, HE & Convertible

75 to 89; XJ12

& HE, Double

P DIGITAL

Refer also to page 39

6 & HE 79 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT =Auto

N/A

= Not available/applicable

™* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

OO

te 2D

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Water temperature sensor:

°C

(between terminals)

10 (50) 20 (68) 80 (176)

(PR)

Air temperature sensor: (between terminals)

°C O

CO at 3000 rpm (%)

HC at idle (ppm)

Injection duration checks

(°F) (32)

20 (68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve _‘|Test terminals

Throttle position switch/sensor 4,2/200

|Test terminals

ohms

H. 2/199

Small duration

Large duration Refer to test procedures

Engine cold:

ms

%

degrees

Similar to, or above, idle values 3.5 4.35 1.28 ms

%

Thermotime switch

Similar to, or above, idle values

2.90

0.87

Ped.

3.66

1.09

251

7.00

2:1

9.99

2.99

> 20

>6

Fuel system checks Fuel pressure - regulator vacuum

pipe

disconnected - bar (Ibf/in2)

2.5 (36) nominal

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

ohms

W & Switch body

degrees

23

Test terminals

Airflow meter/MAP sensor

< 30° C7367 F

0 to 10

Test terminals

ohms

Refer to test procedures

Jaguar/Daimler

LUCAS P DIGITAL

XJ-S V12, HE & Convertible 75 to 89; XJ12 & HE, Double 6 & HE 79 to 89

Airflow sensor MAP sensor (in ECU) Throttle position switch/sensor Auxiliary air valve /dle speed control valve Injectors Thermotime switch ECU (in luggage compartment) Water temperature DOANDAARWBNH™

sensor 70 Air temperature sensor

77 72 73 714 75 76 17 78 79 20

Pressure regu/ator Relays Cold start injector Warm-up regulator Vacuum/pressure switch Fuel filter (in luggage compartment) Metering head Injector resistors Load enrichment device Additional idle contro/ valve

Not all items fitted to all models

H.2/027

H./2783

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

Locate the idle adjuster, which is on the auxiliary air valve at the rear of the engine (nearside bank of cylinders). With the engine at normal operating temperature, run it at around 2000 rpm, and then allow it to idle. Adjust the idle screw to obtain the specified speed.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the ECU, which is located in the vehicle boot. Remove the tamperproof plug, and adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof plug after adjustment.

Lucas P Digital Contents

Ms ees Injection signal and Curation .............ccceeeeeeeeeeees SA TT RIGEUTECITIYESOTENIIG 5200p cecrnennnsspesaounassnmricaseseee © ee PAROLES OSIMIOT, GERSON cccced ces ctenrsasntnevonsunucoesixPea. Ch Mee cate mers Additional full-load SWitChES «0.0.0... cceeeeeeeeee Pe, ews Auxiliary air Valve: scx... UR. RAR kes nee, IMA PSE MSOM cee ae eee re Dee ean ccdense SEP EOeE::- soo Mae Water temperature SENSOF ............cccseceeeeeeeeeeeeeeeees

Injection signal and duration

General Wherever possible, it is advantageous to check for an injection signal and the duration as a first test. In many cases, this will provide a good indication of possible faults

H. 2/200 Injection waveform in the electrical/electronic operation of the system. Refer to Chapter 2 for instructions on how to check for a signal and duration.

Dynamic checks To obtain an injection signal (unless the test equipment is supplied with an adapter), it is usually easiest to roll back the rubber protection boot on one of the injectors, and touch the test lead to each of the two terminals separately, until a signal is obtained. Alternatively, gain access to the ECU terminals with the multi-plug still connected, and refer to the wiring diagram for the appropriate

terminals

to

connect

to,

to

obtain the injection signal. On an engine which will not start, always check the operation of the ignition system

410 410 410 411 411 412 412

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first. The injection system relies on a signal from the ignition system, and will therefore not function if the ECU does not receive an ignition pulse. Check for an injection signal. If there is no signal available at all, refer to the injector checks. If an injection pulse is available, check the injection duration. If the engine is cold, and the pulse is too small, or if the engine is hot, and the pulse too large, refer to the water temperature sensor checks. Also refer to the MAP sensor and throttle position sensor checks. If the engine does run, again check the duration with the engine cold, and then with it hot, and if it is incorrect, refer to the checks detailed above. If the engine is already hot, refer to the water temperature sensor checks for details of the water temperature simulation test. Check for an increase in the duration during a snap acceleration test, and if it is not acceptable, refer to the MAP sensor and throttle position sensor checks. Also check for injection cut-off during deceleration (where used) and if it is not functioning, check the throttle position sensor. lf the above checks appear to provide acceptable results, this generally indicates that the electrical system is satisfactory. If there still appears to be an injection system fault, carry out fuel pressure checks before any detailed electrical component checks are carried out.

Throttle butterfly setting The throttle linkage and throttle butterfly are factory-set, and should not normally be adjusted. If it is necessary to check or adjust the butterfly closed position, the following procedure can be used. Slacken off the throttle linkage stop screw on the throttle body until there is a small air gap. Screw the stop screw in an additional half-turn. This should result in an air gap of approximately 0.05 to 0.15 mm (0.002 to

412 412 413 413 415 415

H.21205

Throttle butterfly air gap (typical) 0.006 in) between the throttle butterfly and the throttle casing. On vehicles that do not have an automatic idle speed control, with the idle bypass screw fully closed, the idle speed will typically be around 600 to 650 rpm with the correct butterfly air gap. After setting the butterfly, check the Operation of the throttle position switch or sensor.

V712 engine Slacken the throttle linkage stop screws for both butterflies, and ensure that the butterflies are fully closed. Screw in the stop screw until an air gap of 06.05 mm (0.002 in) exists between the butterfly and the throttle body casting. Tighten the locknuts on the adjusting screws, and check the operation of the throttle linkage to, ensure that the butterflies open together. Also check the throttle switch operation.

Throttle position sensor General description The throttle position sensor is used to indicate throttle position, and rate of change of the throttle position. The sensor is of the variable resistor type, and supplies a varying voltage signal to the ECU.

411 Lucas

P Digital

open (fast idle) until the engine coolant, which is flowing across a thermostat in the valve, heats up — this forces the valve to close. Note: 7he idle adjuster is located on the valve body.

Dynamic checks Engine cold Where possible, clamp shut one of the two air hoses connecting the air valve to the induction system. If the valve is functioning, the idle speed will drop. If there is no drop in the idle speed, this indicates faulty valve

H. 2/425 Throttle position sensor

operation.

Static checks Check the voltage readings at the throttle sensor connector plug with the engine running. One terminal should be a constant power supply, the remaining terminals should provide a zero voltage reading, and a reading that varies as the throttle is opened and closed. Check for a smooth increase and decrease in the voltage, and if it is unacceptable, check the connections or refer to the following resistance checks. If there is no supply voltage, check the wiring through to the ECU (refer to the wiring diagram). With the connector plug disconnected, check the resistances across the sensor wires. One pair of wires should provide a resistance of around 5 K ohms, irrespective of throttle position. Using one of these wires and the remaining wire, the reading should change as the throttle is opened and closed. The reading should fall to between approximately 5 K ohms and approximately 125 ohms at the extremes of the _ throttle movement. If the change in resistance is erratic, or if the reading goes open- or short-circuit at any point between closed and open positions, the sensor should be renewed.

Additional

full-load switches

General description Some models are fitted with additional full-load switches, to indicate to the ECU when full-load operation occurs. The two switches are wired into the same circuit, but one is vacuum-controlled, and the other is a throttle by the operated microswitch linkage.

Static checks Check the vacuum switch by disconnecting the manifold vacuum pipe and the wires. Check for continuity connecting terminals. Apply vacuum switch the across to the switch, or reconnect the switch to the

Full-load

switch

Engine warm Where possible, clamp shut one of the two air hoses connecting the air valve to the induction system. If the idle speed drops, it indicates faulty valve operation. If there is no drop in idle speed, this indicates correct valve operation. *Note: /f /t is difficult to clamp an air hose for either of the above tests, one of the hoses should be disconnected, and both openings blanked off. Restart the engine, and note whether the speed is the same or reduced. The same conclusions can be drawn as for tests with the hoses clamped. The above checks can be carried with the valve disconnected from the engine, but note that the engine coolant will need to be drained. With the valve placed in hot water, it should be possible to establish that the valve is closed by trying to blow through it. In cold water, the valve should be open.

H.2l427

Full-load

switch

vacuum pipe and allow the engine to idle, and note that the switch should now open (open-circuit reading). If the switch contacts are not functioning, renew the switch. The microswitch can be checked by disconnecting the wires, and testing for continuity across the terminals when the throttle is fully opened. When the throttle is closed, the contacts should open. The switch can be adjusted if necessary by slackening the securing screws.

Auxiliary air valve General description The auxiliary air valve provides a fast idle when the engine is cold, and also during the initial warm-up period. As the engine warms up, the valve progressively closes, reducing the idle speed to normal. The valve remains

H.21428. Auxiliary air valve

412

Lucas P Digital

MAP

sensor

If, during the simulation tests, there is no noticeable difference in the duration

General description A MAP

measurements,

is located in the ECU, and is connected to the

MAP

intake

system

sensor

manifold

by a vacuum

detects

the

vacuum/pressure,

responds to the changes injection duration.

pipe.

changes and

The

the

by altering

ECU

Air temperature

the

plug

and

sensor

General description

Run the engine (at normal operating temperature) at around 1500 rpm. Disconnect the vacuum pipe from the ECU (quickly block the open end of the pipe), and note that the injection duration and CO reading should increase slightly. Note that it is possible that the engine may stall. If there is no change, suspect the ECU. Also ensure that the vacuum from the engine is reaching the sensor via the pipe. VACUUM CONNECTION TO MAP SENSOR

ye

sensor

Water temperature

the sensor

in the

The air temperature sensor supplies a voltage signal to the ECU, which will vary with air inlet temperature. The ECU finely adjusts the mixture depending on the signal.

Dynamic checks

MAP

check

wiring for continuity to the ECU terminal and to earth (refer to the wiring diagram). If there is no wiring fault, suspect the ECU.

(manifold absolute pressure) sensor

sensor

The sensor is very similar in operation to the

water temperature sensor.

Static checks H. 2/1204 Water temperature sensor Plug terminal is blue or white measure the resistance across the sensor terminals, comparing the readings with those specified. If the sensor is not removed from the engine, it is advisable to take measurements with the engine cold, and then with it hot, to establish the change in resistance in conjunction with the change in temperature. The sensor can, however, be removed and tested in water at various temperatures. If the sensor resistances are correct, check the connections and the continuity of the wiring from the two sensor plug terminals to the ECU and earth (refer to the wiring diagram).

Locate the sensor in the intake system, and disconnect the electrical plug. Measure the resistance across the sensor terminals, and compare with the specified values. A faulty sensor will usually be indicated by a short- or open-circuit, but if necessary, check the readings at different air temperatures to ensure that a change in resistance occurs. Check the wiring through to the ECU (refer to the wiring diagram), and rectify if necessary.

General description The water temperature sensor provides a varying voltage signal to the ECU to indicate engine coolant temperature. This enables mixture correction to take place in response to engine temperature changes.

Dynamic checks Carry out an injection duration check, and refer to the specified readings. Checking the duration on a cold engine should provide a large duration, which should reduce as the engine warms up. If the engine will not start, the duration can be checked during cranking, but note that the first few moments may provide a higher duration reading than specified. During cranking or running, a substantially smaller than specified duration when cold, or a substantially larger duration when hot, indicates a probable sensor or sensor circuit fault, but refer to the water temperature simulation test.

Static checks Pull off the sensor

connector

plug, and

Water temperature simulation test With the engine switched off, pull off the connector plug from the water temperature sensor, and bridge the connector plug terminals with a suitable piece of wire, or preferably, a resistor of approximately 200 to 300 ohms. This will provide a hot-engine simulation. Crank, and if possible, start the engine (run at 1500 rpm), and note the injection duration, which should be close to the specified reading for a warm engine. Switch the ignition off, and remove the. bridging wire or resistor. Either leave the plug terminals unconnected, or preferably, bridge with a resistor of approximately 6 Kohms or more, to simulate a cold engine. (This simulation can cause extreme flooding of the engine, preventing starting.) Repeat the test, which should now provide a noticeably larger duration than for the hot-engine simulation. The duration reading should be close to, or greater than, the specified value for a cold engine. If the engine fails to start due to flooding, this indicates correct ECU response.

Air temperature

sensor

Injectors General description The injectors receive a live feed from the control relay, and are switched through to earth via the ECU. A set of power or ballast resistors is connected in the earth circuit ta reduce the current when the injectors are switched on, but a bypass to the resistors is included for high current consumption during the switch-on period. The injectors are wired to the ECU in two groups of three on the six-cylinder engines, and in four groups of three on the twelvecylinder engines. If a power resistor was therefore to fail, it would prevent three injectors from remaining open for the full

Lucas

413

P Digital

the resistor box terminals as follows:

Six-cylinder engines 6to 8 4 to 10

Twelve-cylinder engines Ral in geht; 4 to 10 6to 8

In all cases, a resistance of around 6 ohms should be measured. If the reading is open-circuit,

renew the resistor.

Note: /f there is no fault found during the above checks, but it is apparent that one or more injectors are not functioning correctly, it is probable that fouling exists in the faulty injectors — refer to Chapter 2.

Fuel system pressure and fuel AH. 21202

Connection to an injector duration. Note that on_ twelve-cylinder engines, the injectors are triggered in two groups of six.

Dynamic checks Crank or run the engine, and listen to each injector for a clicking sound as the injector operates (it may be necessary to use a suitable listening device, such as a screwdriver, as a ‘stethoscope’). If it appears that one or more injectors are not functioning, carry out the following checks. Check for injection signal and duration, and if correct, carry out the static injector checks. If there is no injection signal, check for a supply voltage from the control relay to the injectors. Refer to the relay checks and the wiring diagram if the relay is not supplying voltage. Check for continuity of the wiring from the injector plugs through the power resistors (approximately 6 ohms) to the ECU multi-plug, and also the by-pass circuit to the ECU (refer to the wiring diagram). If there is no continuity, renew the resistors or rectify the wiring as necessary. If the injection signal exists, but the duration appears to be incorrect (recheck the resistors), or if supply voltage is correct, and there is still no injection signal, refer to the ECU checks for a guide to further tests.

pump

checks

Fuel pump relay — bypassing For a number of the following tests, it is necessary to crank the engine in order to allow the pump to run. It is possible to by-pass the pump relay, which will allow the pump to run without cranking. Locate and disconnect the fuel pump relay from its holder. Bridge the connectors on the relay holder which correspond to terminals 30 (battery positive) and 87 (pump supply). The bridging wire should be fitted with a 20 amp fuse, to protect against a possible short-circuit.

Fuel system pressure checks The

system

should

provide

fuel

to the

fuel rail and injectors, at a pressure which is constant in relation to manifold pressure. The system consists of a fuel pump, main filter, fuel rail (to distribute the fuel to the injectors) and injectors, which contain a fine filter. To maintain

the

pressure,

a pressure

regulator is fitted, which allows excess fuel back to the tank. The regulator is connected to the inlet manifold via a vacuum pipe, in order to adjust the fuel pressure in conjunction with changes in the manifold pressure. Note: Before disconnecting any of the fuel lines, it is advisable to disable the fuel pump and run the engine, to depressurise the fuel system. The fuel pump relay is incorporated in the system relay, preventing the pump supply from being disconnected without disabling the rest of the injection system. It is therefore necessary to independently disconnect the fuel pump electrical connections directly at the pump. Disable the fuel pump, and run the engine until it stops, to depressurise the fuel system. Locate the fuel supply line to the fuel rail, and disconnect the supply line. Connect the fuel pressure gauge as indicated in equipment manufacturer's instructions. Wherever possible, locate a tap between the gauge and the fuel rail. Reconnect the fuel pump, and start the engine (make sure that if a tap is fitted with

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87)

87B

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87B

Live feed to terminal 30 Cold start relay Live feed to fuel pump

Terminal

15 ECU

Live feed from 87B Main control relay Battery

+ve

Live feed to injectors bank B, terminal 86 Fuel pump

relay

O Live feed to injectors bank A, terminal 22 ECU © Earth connection © Live feed from ignition switch © Battery

+ve

H. 21431

Relay wiring diagram

Injection ECU

Note:

Bank

B

connect with ECU at terminals 8 and 9/28 and 29

Terminal 87/87B (bank B) Main control relay

Bank A injectors

H. 2/433

Lucas P Digital wiring diagram

4 Lucas

Injection

P Digital

es

ECU

O

Terminal 1 Coil

Live when cranking

O

O

Thermotime switch

Cold start injectors banks A and

Terminal 87B Fuel pump relay

Earth connection

Cold start relay

B

H. 2/434

Lucas P Digital wiring diagram

Injection ECU

©

O

Injector resistors bank A

Injector resistors bank B

Lambda sensors banks A and B

H. 2/435

Lucas P Digital wiring diagram

Live when

cranking

Earth connection

Ane

Lucas P Digital

Injection ECU

QO Earth connection

Air temperature

Water temperature

sensor

sensor

Full load switches

Throttle sensor

H. 2/432

Lucas P Digital wiring diagram

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Mazda

MAZDA

EGI

Refer also to page 39

323 1600i 85 to 87; 323 1.61 87 to 89; 323 Turbo 4x4 86 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

900 to 1000 M

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Water temperature sensor:

10. (50) 20 (68) 80 (176) CO at 3000 rpm (%) SH crete ge)

Air temperature sensor:

pc

(FP)

Injection duration checks

(THA & E2 in ee

O (32) 20 (68)

Refer to Chapter 2

Injection waveform

Auto idle speed control valve _‘ [Test terminals

Throttle position switch/sensor

H. 2/201 Small duration

Engine cold:

:

Large duration

ms

Co)

%

degrees

Similar to, or above, idle values 4 ms

6.33

5.69

%

degrees

Thermotime switch

|Test terminals

ohms

IDE Gat

0 to 10

PSW & TL

beg) Infinity

IDL & TL

Infinity

PSW & TL

0 to 10

Test terminals

ohms

Similar to, or above, idle values 200

S40

xElols)

2.4

4.00

3.60

2000 rpm

2.3

7.66

6.89

Test terminals

ohms

3000 rpm

Que

11.00

9.90

E1 & FC

Infinity

ar

Als

E1 & FCt

Oto 10

Snap open throttle

: Airflow meter/MAP sensor

Fuel system checks Fuel pressure - regulator vacuum pipe

"421320

disconnected - bar (Ibf/in?)

2.5 to 2.8 (36 to 40)

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

E2 &VS

Up to 1000

EZ ove

130 to 260

ae

Mazda

MAZDA

EGI

323 1600i 85 to 87; 323 1.61 87 to 89; 323 Turbo 4x4 86 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve /njectors Thermotime switch ECU (under facia) Water temperature sensor DANDARWNH™ 10

Air temperature sensor

17 Pressure regulator 72 Relays (under facia) 73 Cold start injector 74 Warm-up regulator 75

Vacuum/pressure

76 77 78 19 20

Fuel filter Metering head Injector resistors Load enrichment device Additional idle control valve

switch

Not all items fitted to all models

he

DD CO (mixture) adjustment

Idle speed adjustment

7

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for _ approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster 2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the co or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

424

Mazda

MAZDA

EGI

Refer also to page 39

626 2000: 85 to 87; 626 2.01 GT 87 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks Resistance characteristics

Basic checks 850 to 900 (up to 1987)

Idle speed (rpm)

Injectors (ohms)

750 + 5 (from 1987)

Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

2 + 0.5 (up to 1987)

Water temperature sensor:

°Ct

1.5 + 0.5 (from 1987)

(between terminals)

TO) 50} 20 (68) 80 (176)

(eR)

20

> 18

Airflow meter/MAP sensor

FC

Dwell readings are invalid on dwell meter

E2 —1

VC Bi

THA OVS:

Fuel system checks CI

Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min) ....

H.2/320

2.4 to 2.8 (35 to 41) 1.5 to 2 (2.6 to 3.5)

Mazda

MAZDA

EGI

626 2000: 85 to 87; 626 2.01 GT 87 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve

/njectors Thermotime switch ECU (under facia) ARWH™ WANA Water temperature sensor 70 Air temperature sensor 17 Pressure regulator 72

Relays

73 14 715 16 17 78 19 20

Cold start injector Warm-up regulator Vacuum/pressure switch Fuel filter Metering head Injector resistors Load enrichment device Additional id/e contro/ valve

Not all items fitted to all models

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1’ on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2° on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

Mazda

EGI

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Warottle butterily setting: 2... OR

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Injection signal and duration General Wherever possible, it is advantageous to check for an injection signal and the duration as a first test. In many cases, this will provide a good indication of possible faults in the electrical/electronic operation of the system. Refer to Chapter 2 for instructions on how to check for injection signal and duration. Note: Due to the type of injection signal provided by this system, when attempting to carry out duration checks with a dwell meter, it is possible that incorrect readings may occur. The preferable method of checking injection duration is to observe an oscilloscope waveform.

H. 2/201 Injection waveform

Dynamic checks To obtain an injection signal (unless the test equipment

is supplied with an adapter),

it is usually easiest to roll back the rubber protection boot on one of the injectors, and touch the test lead to each of the two terminals separately until a signal is obtained. Alternatively, gain access to the ECU terminals with the multi-plug still connected, and refer to the wiring diagram for the

appropriate

426 426 426 427 428 428

terminals

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to

429 429 429 430 431

checks, fault diagnosis and wiring diagrams

connect

to,

to

obtain the injection signal. On an engine which will not start, always check the operation of the ignition system first. The injection system relies on a signal from the ignition system, and will therefore not function if the ECU does not receive an ignition pulse. Check for an injection signal. If there is no signal available at all, refer to the injector checks. If an injection pulse is available, check the duration. If the engine is cold, and the pulse is too small, or if the engine is hot, and the pulse is too large, refer to the water temperature sensor checks. Also refer to the airflow meter checks. If the engine does run, again check the duration cold and hot, and if it is incorrect, refer to the checks as detailed above. If the engine is already hot, refer to the water temperature sensor checks for details of the water temperature simulation test. Check for an increase in the duration during a snap acceleration test, and if it is not acceptable, refer to the airflow meter checks. Also check for injection cut-off during deceleration (where used), and if it is not functioning, check the throttle position sensor. If the above checks appear to provide acceptable results, this generally indicates that the electrical system is satisfactory. If there still appears to be an injection system fault, carry out the fuel pressuré checks before any detailed electrical component checks are carried out.

Throttle butterfly setting The throttle linkage and throttle butterfly are factory-set, and should not normally be adjusted. If it is necessary to check or adjust the butterfly closed position, the following procedure can be used.

Slacken off the throttle linkage stop screw on the throttle body until there is a small air gap. Screw the stop screw in an additional half-turn.

This should result in an air gap of approximately 0.05 to 0.15 mm (0.002 to 0.006 in) between the throttle butterfly and the throttle casing. On vehicles that do not have an automatic idle speed control, with the idle bypass screw fully closed, the idle speed will typically be around 600 to 650 rpm with the correct butterfly air gap. After setting the butterfly, check the operation of the throttle position switch or sensor.

H.21205

Throttle butterfly air gap (typical)

Throttle position switch General description The

throttle

position

switch

indicates

to

the ECU the idle and full-load positions, via two sets of contacts in the switch body. When neither of the two switched positions is indicated, a part-load condition is assumed. Mixture correction takes place depending on the switch position. Automatic idle speed control valve operation (where fitted) and deceleration fuel cut-off are implemented when the _ idle position is indicated.

Static checks Disconnect the plug from the throttle switch, and with the engine cranking or running, check for approximately 12 volts to

Mazda

427

EGI

Auxiliary air valve

General description The auxiliary air valve provides a fast idle when the engine is cold, and during the initial warm-up period. As the engine warms up, the valve progressively closes, reducing the idle speed to normal. The valve remains

open (fast idle) until a combination of engine heat and electrical heating force it to close.

Dynamic checks

AH ZISZ7. Throttle position switch each of the outside terminals on the plug (terminals 2 and 3). If there is no voltage at one or both of the terminals, check the wiring through to the ECU. With the plug disconnected and the throttle closed, check for continuity between the centre terminal (TL) and terminal IDL of the switch. If it is open-circuit, slacken the securing screws and rotate the switch until continuity exists. If there is still no continuity, renew the switch. Check that the idle contacts open when the throttle is opened. Note: Jhe throttle butterfly adjustment should be correctly set before adjusting idle position switch. Check for continuity between the switch centre terminal (TL) and terminal STW with the throttle fully open. If there is no continuity, renew the switch. Check that the full-load contacts are open when the throttle is closed. With the plug disconnected, check for continuity between the plug terminals and the ECU multi-plug (refer to the wiring diagram). If there is no continuity, rectify the wiring fault.

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Throttle position switch/sensor Large duration

Engine cold:

Crankincer

Test terminals

H. 21199

Small duration

CranKING %.

Auto idle speed control valve

eater ae

Fuel system checks Fuel pressure - regulator vacuum pipe disconnected - bar (Ibf/in2) ..............

2.6 (37) nominal

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

Airflow meter/MAP

sensor

Test terminals

Refer to test procedures

NISSAN

Reliant Scimitar SS1

ECCS

1800 Ti 86 to 89

Airflow sensor MAP sensor Throttle position switch/sensor

Auxiliary air valve /dle speed control valve Injectors Thermotime switch ECU (in passenger footwell) Water temperature sensor WOOANDAAARWH™ 70 Air temperature sensor 17 Pressure regulator 72 Relays 73 Cold start injector 714 Warm-up regulator 15 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H.19354

H.19353

CO (mixture) adjustment

Idle speed adjustment 1

2

Idle bypass adjuster screw

Idle speed adjustment The engine is fitted with an additionai idle control valve, but the basic idle speed can be set via the adjuster ‘1’ on the air intake chamber. Run the engine at approximately 2000 rpm for around twenty seconds, and allow it to idle. Remove the tamperproof plug (where fitted), and adjust the speed to that specified, then fit a new tamperproof plug.

co (mixture) adjustment The CO adjustment should be carried out with a 2.5 K ohm resistor fitted to the temperature sensor plug. This should result in a specified

CO (mixture) adjuster screw

CO reading of 4%. When this procedure is carried out, after the resistor is removed and the sensor plug reconnected, the CO reading should be as specified. In the absence of the appropriate resistor, the following procedure can be used. Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Screw in the adjuster to increase the CO level, or unscrew the adjuster to reduce the CO level. Set the CO level to that specified, and fit a new tamperproof plug.

Nissan

ECCS

Contents

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Injection signal and duration General Wherever possible, it is advantageous to check for an injection signal and the duration as a first test. In many cases, this will provide a good indication of possible faults in the electrical/electronic

operation

of the

system. Refer to Chapter 2 for instructions on how to check for injection signal.and duration.

Dynamic checks To obtain an injection signal (unless the test equipment is supplied with an adapter), it is usually easiest to roll back the rybber protection boot on one of the injectors, and touch the test lead to each of the two terminals separately until a signal is obtained. Alternatively, gain access to the ECU terminals with the multi-plug still connec-

H, 2/200 Injection waveform

446 446 446 447 447 448 448 448

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449 450 450 451 453 453 453

ted, and refer to the wiring diagram for the appropriate terminals to connect to, to obtain the injection signal. On an engine which will not start, always check the operation of the ignition system first. The injection system relies on a signal from the ignition system, and will therefore not function if the ECU does not receive an ignition pulse. Check for an injection signal. If there is no signal available at all, refer to the injector checks. If an injection pulse is available, check the

duration. If the engine is cold, and the pulse _ is too small, or if the engine is hot, and the pulse is too large, refer to the water temperature sensor checks. Also refer to the airflow meter checks. If the engine does run, again check the duration cold and hot, and if it is incorrect, refer to the checks as detailed above. If the engine is already hot, refer to the water temperature sensor checks for details of the water temperature simulation test. Check for an increase in the duration during a snap acceleration test, and if it is not acceptable, refer to the airflow meter checks. Also check for injection cut-off during deceleration (where used), and if it is not functioning, check the throttle position sensor. If the above checks appear to provide acceptable results, this generally indicates that the electrical system is satisfactory. If there still appears to be an injection system fault, carry out the fuel pressure checks before any detailed electrical component checks are carried out.

Throttle butterfly setting The throttle linkage and throttle butterfly are factory-set, and should not normally be adjusted. If it is necessary to check or adjust the butterfly closed position, the following

H.21205

Throttle butterfly air gap (typical) procedure can be used. Slacken off the throttle linkage stop screw on the throttle body until there is a small air gap. Screw the stop screw in an additional half-turn. This should result in.an air gap of approximately 0.05 to 0.15 mm (0.002 to 0.006 in) between the throttle butterfly and the throttle casing. On vehicles that do not have an automatic idle speed control, with the idle bypass screw fully ciosed, the idle speed will typically be around 600 to 650 rpm with the correct butterfly air gap. After setting the butterfly, check the operation of the throttle position switch or sensor.

Throttle position switch General description The throttle position switch indicates to the ECU the idle position, via a set of contacts in the switch body. Mixture correction takes place when the switch is in the closed or idle position. A second set of contacts is fitted for indicating full throttle,

Nissan

447

ECCS

29

AH2/200

30

Auxiliary air valve

H. 21327 Dynamic checks

Throttle position switch but this facility is not normally used on this application. -

Static checks Disconnect the plug from the switch, and check for continuity between terminals 29 and 30 with the throttle closed. Note that the numbers correspond to ECU terminals 25 and 18. Open the throttle, and the switch should open, providing an infinity reading. If necessary, adjust the throttle switch so that when the throttle is slightly open and maintaining an engine speed of approximately 900 rpm, the contacts are closed. Check for continuity of the wiring through to the ECU (refer to the wiring diagram).

Throttle switch

and sensor

General description The throttle position switch indicates to the ECU the idle position, via a set of contacts in the switch body. Mixture correction takes place when the switch is in the closed or idle position. A second set of contacts is fitted for indicating full throttle, but this facility is not normally used on this application, except for some CA20E type engines. An additional sensor is incorporated into the switch body, which is of the variable resistor type. The sensor indicates rate of change of throttle position, as well as its actual position.

Static checks Disconnect the plug from the switch body, and check for continuity between terminals 29 and 30 with the throttle closed. Open the throttle, and the switch should open, to provide a reading of infinity. If necessary, adjust the throttle switch so that when the throttle is slightly open and maintaining an engine speed of approxi-

H.2/345 Throttle position switch mately 900 rpm, the contacts are closed. Check for continuity of the wiring through to the ECU (refer to the wiring diagram). On some CA20E type engines, the second set of switch contacts are used, and these should close when the throttle is fully open. Check between terminals 30 and 24 with the throttle fully open. If there is no continuity, renew the switch. Locate the connector plug for the throttle sensor, which is part of the throttle switch. Using a thin probe, check between terminals 4 and 6 for approximately 5 volts with the engine running. If the voltage is unavailable, check the wiring through to the ECU (refer to the wiring diagram). Check between terminals 4 and 5 for a varying voltage which is dependent on throttle position. The voltage should rise from almost zero volts to approximately 4.5 volts when the throttle is fully opened. If the voltage does not alter, or is not available, renew the sensor.

Auxiliary air valve General description The auxiliary air valve provides a fast idle when the engine is cold, and during the initial warm-up period. As the engine warms up, the valve progressively closes, reducing the idle speed to normal. The valve remains open (fast idle) until a combination of engine heat and electrical heating force it to close.

Engine cold Where possible, clamp shut one of the two air hoses* connecting the air valve to the induction system. If the valve is functioning, the idle speed will drop. If there is no drop in the idle speed, this indicates faulty valve operation. Engine warm Where possible, clamp shut one of the two air hoses* connecting the air valve to the induction system. If the idle speed drops, it indicates faulty valve operation. If there is no drop in idle speed, this indicates correct valve operation.

*Note: /f it is difficult to clamp an air hose for either of the above tests, one of the hoses should be disconnected, and both openings blanked off. Restart the engine, and note whether the speed is the same or reduced. The same conclusions can be drawn as for tests with the hoses clamped.

Static checks Disconnect the two air hoses from the valve body, and examine the opening of the valve port, either by using a mirror if necessary, or by removing the valve from the engine. The valve should be open if the engine is cold, or closed if the engine has been running for more than five minutes. A valve that has stuck open or closed may with a_ suitable benefit from cleaning solvent. If a valve remains closed, it will probably need renewing. When a valve remains open, it may be caused either by a broken heater element, or a faulty electrical circuit to the heating element. With the plug disconnected, check for the specified element resistance by measuring across the valve terminals. If the reading indicates a short- or open-circuit, renew the valve. An alternative test can be carried out by battery voltage independently supplying and an earth connection to the valve terminals. The valve should completely close

448

Nissan

ECCS

when additional engine.

load

is applied

to

the

Static checks

©.8 /

PARTIALLY OPEN

CLOSED

H.212/4

Run the engine to normal operating temperature, allow to return to idle, and switch on the air conditioning if fitted, or alternatively, switch on the heated rear window or the headlights. If the engine speed drops too low, the valve should then open to restore the speed. If it is suspected that the valves are not functioning, disconnect the four-terminal plug from the idle valve harness. Identify the two pairs of wires going to each valve, and check for a resistance between the two terminals of each pair. If there is an opencircuit, the valve should be renewed. If the circuits are satisfactory, remove the valves and clean with a suitable solvent. Also carry out a wiring check (refer to the wiring diagram).

Auxiliary air valve ports

Static checks With the engine at normal temperature and idle speed, ensure that there is no additional load applied. Disconnect the electrical connector from the valve, and apply battery voltage and an earth to the valve. The valve should operate, raising the idle speed by approximately 100 rpm. If thevalve does not function, reverse the connections. If the valve still does not function, prise off the blanking plug from the valve, and adjust the idle spéed to approximately 100 rpm greater than specified. If the adjuster does not have any effect, the idle valve should be renewed.

Idle control

valve

Idle-up and fast idle valve

Airflow meter and air perature sensor (mechanical type)

Auxiliary air valve (Cherry Turbo) within three to four minutes. If the valve does not close, cleaning with a suitable solvent may effect a cure, but otherwise the valve should be renewed. If the valve functioned when an independent supply and earth are used, but it does not operate when connected to the vehicle electrical system, carry out a wiring check (refer to the wiring diagram).

1.21348,

General description

tem-

.

The airflow meter indicates to the ECU the variation airflow to the engine. Incorporated into the airflow meter is the air temperature sensor, for fine-tuning the mixture strength.

Dynamic checks Fast idle adjuster

Idle-up and fast idle valve

General description

General description

The idle control valve is used to maintain the idle speed when additional load is applied to the engine.

The idle-up and fast idle valve are combined into one casing. The valves are used to raise or maintain the idle speed

An indication of poor airflow meter response can be obtained by checking the injection duration. Note the duration at 2000 rpm, and again during snap acceleration. If there is no substantial increase in duration, it usually indicates an airflow meter fault. Alternatively, gain access to the airflow meter flap by removing the assembly from the air filter casing. With the electrical

Nissan

449

ECCS

AH 2/201.

Airflow meter (mechanical type) connector plug and_ remaining intake trunking still connected, run the engine at around 1200 rpm, and note the injection duration or exhaust gas CO reading. Slowly push open the airflow meter flap, which will simulate an increase in airflow (also check for a sticking flap). The injection duration and the CO level increase, and it is likely that the engine will attempt to stall due to flooding. If the increase in readings does not occur, or the flap is sticking, continue with the following checks. Preferably using the low-voltage facility of an oscilloscope, or a digital voltmeter, check the output voltage from the airflow meter on terminal 32. To gain access to the terminal, roll back the rubber protection boot from the airflow meter connector, and locate the wire corresponding to terminal 32: With the connector in place, crank, or where possible run, the engine. Connect the oscilloscope or volt test lead to the exposed terminal connection, and note the voltage. With the engine running, slowly open the throttle, and note the progressive increase in voltage. A delay in the increase, or no increase at ~ all, usually indicates a sticking flap in the airflow meter. In most cases, this can be cured by cleaning. An erratic change in voltage, or hash on the oscilloscope trace, often indicates a fault in the resistance track, and this is not normally serviceable. Also check for a voltage increase when the throttle is quickly snapped open. If there is no voltage reading, or if the voltage change is erratic refer to the static checks.

Static checks Note: EF/ectrica/ faults in the airflow meter are not normally serviceable.

Disconnect the connector plug from the airflow sensor, and check the resistances across the airflow meter plug terminals, comparing with those specified. A reasonable tolerance is indicated by the specified

AH. 2/203

Moving airflow meter flap values, but a fault is usually indicated by an open- or short-circuit. When checking between terminals 32 and 34, gain access to the airflow meter flap, by removing the assembly from the air filter casing, and slowly push the flap open to its limit. The resistance reading should increase and decrease in a series of steps. A fault will normally be indicated by an open-circuit at some stage during the flap movement. Also check for mechanical resistance as the flap is moved, especially near the closed position. A sticking flap can often be cured by cleaning, but if not, the assembly should be renewed. The air temperature sensor resistance reading between terminals 25 and 34 will depend on the ambient air temperature. If a resistance reading within the highest and lowest specified values is obtained, it is unlikely that a fault exists. Checks can, however, be carried out by altering warming or cooling the air temperature sensor” and noting resistance changes.

* Warning: Do not use a naked flame to warm the air temperature sensor.

When carrying out the dynamic checks, if there is a zero volt reading, carry out the first static check, but also check for supply voltage to terminal 33 on the airflow meter connector, with the engine cranking or running. The supply voltage originates from the ECU terminal 33. Also check for continuity of the wiring from connector plug terminals 25, 32, 33, 34 and 35, to the corresponding pins on ECU (refer to the wiring diagram).

H. 2/452 Airflow

sensor

terminals

Airflow sensor (hot wire type) General description The airflow meter indicates to the ECU the variation in airflow to the engine. The airflow meter operates on the hot wire principle, and combines a built-in correction for air temperature.

Dynamic checks An indication of poor airflow meter response can be obtained by checking the injection duration. Note the duration at 2000 rpm, and again during snap acceleration. If there is no substanial increase in duration, it usually indicates an airflow meter fault. Preferably using the low-voltage facility of an oscilloscope, or a digital voltmeter, check the output voltage from the airflow meter on terminal D. To gain access to the terminal, roll back the rubber protection

450

Nissan

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ECCS

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H. 2/456

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Airflow sensor

(hot wire type)

boot from the airflow meter connector,and locate the wire corresponding to terminal D (four-terminal airflow meter) or terminal B (six-terminal airflow meter). With the connector in place, crank, or where possible run, the engine. Connect the oscilloscope or volt test lead to the exposed terminal connection, and note the voltage. With the engine running, slowly open the throttle and note the progressive change in voltage. Also check for a substantial voltage change when the throttle is quickly snapped open. If there is no voltage reading, or if the voltage change does not occur, refer to the

static checks.

Airflow

sensor

terminals

1 to 2 volts on the six-terminal type. Where possible, blow through the airflow meter, and check for a change in the voltage. If the readings are incorrect, renew the airflow meter.

Water temperature General description

The water temperature sensor provides a varying voltage signal to the ECU, to indicate engine coolant temperature. This enables mixture correction to take place, in response to engine temperature changes.

Dynamic checks Carry out an injection duration check, and refer to the specified readings. Checking the duration on a cold engine should provide a large duration, which should reduce as the engine warms up. If the engine will not start, the duration can be checked during cranking, but note that the first few moments may provide a higher duration reading than specified. During cranking or running, a substantially smaller than specified duration when cold, or a substantially larger duration when hot, indicates a probable sensor or sensor circuit fault, but refer to the water temperature simulation test.

Static checks

Airflow

sensor

terminals

Static checks Note:

E/ectrica/ faults in the airflow meter

are not normally serviceable. Disconnect the connector plug from the airflow sensor, and apply battery voltage to terminals C and D (four-terminal airflow meter) or terminals D and E (six-terminal airflow meter). Measure the voltage between C and D on the four-terminal type, or between B and D on the six-terminal type. Check for a voltage of between 0.6 to 1 volt on the four-terminal

type, or approximately

H.21204

sensor

Pull off the sensor connector plug, and measure the resistance across the sensor terminals, comparing the readings against those specified. If the sensor is not removed from the engine, it is advisable to take measurements with the engine cold, and then with it hot, to establish the change in resistance in conjunction with the change in temperature. The sensor can, however, be removed and tested in water at various temperatures. If the sensor resistances are correct, check the connections and continuity of the wiring from the two sensor plug terminals to the ECU (refer to the wiring diagram).

Water temperature simulation test With the engine switched off, pull off the connector plug from the water temperature

Water temperature sensor Plug terminal is blue or white sensor, and bridge the connector plug terminals with a suitable piece of wire, or preferably a resistor of approximately 200 to 300 ohms — this will provide a hot engine simulation. Crank, and if possible, start the engine (run at 1500 rpm), and note the injection duration, which should be close to the specified reading for a warm engine. -Switch the ignition off, and remove the bridging wire or resistor. Either leave the plug terminals unconnected, or preferably bridge with a resistor of approximately 6 K ohms or more, to simulate a cold engine. This simulation can cause extreme flooding of the engine, preventing starting. Repeat the test, which should now provide a noticeably larger duration than during the hot-engine simulation. The duration reading should be close to, or greater than, the specified value for a cold engine. If the engine fails to start due to flooding, this indicates correct ECU response. If, during the simulation tests, there is no noticeable difference in duration measurements, check the sensor plug and wiring for continuity to the ECU terminal and to earth (refer to the wiring diagram). If there is no wiring fault, suspect the ECU.

Injectors General description The injectors receive a live feed from the control relay, via a set of ballast or power resistors (one for each injector). The injectors are switched on and off on the earth circuit, via independent connections through the ECU.

Dynamic checks Crank or run the engine, and listen to each

Nissan

451

ECCS

Fuel system pressure pump checks

and fuel

Fuel pump relay — bypassing For a number of the following tests, it is necessary to crank the engine in order to allow the pump to run. It is possible to bypass the pump relay, which will allow the pump

AH. 21202

Connection to an injector injector for a clicking sound as the injector Operates (it may be necessary to use a suitable listening device, such as a screwdriver, as a ‘stethoscope’). If it appears that one or more injectors are not functioning, carry out the following checks. Check the injection signal and duration, and if correct, carry out the static injector checks. If there is no injection signal, check for supply voltage from the power resistors, and if necessary from the control relay to the resistors. Refer to the relay checks Section if the relay is not supplying voltage to the resistors, or renew any faulty resistors if necessary. Check the continuity of the wiring from the injector plugs to the ECU multi-plug connector — disconnect all other system connector plugs, and refer to the wiring diagram. If the injection signal exists, but the duration appears to be incorrect, or if supply voltage is correct, and there is still no injection signal, refer to the ECU checks for a guide to further tests.

Static checks Remove the connector plug from the injector(s), and check the resistance across the two injector terminals, comparing with the reading specified. Also ensure that there is no continuity between the injector body and the injector terminals. Note: /f there is no fault found during the above checks, but it is apparent that one or more injectors are not functioning correctly, it is probable that fouling exists in the faulty injectors, and a flow rate test may be required — refer to Chapter 2.

to run without cranking.

Locate the control relay, which also acts as the pump relay. Remove the relay, and locate the terminal on the relay holder that is permanently live. Bridge the live terminal to the fuel pump wire, which will then run the pump. The bridging wire should be fitted with a 20 amp fuse to protect against a possible short-circuit. Due to the variations that exist in the wiring colours, it will be necessary to check for continuity between the relay holder terminals and the fuel pump, to establish which of the relay terminals connects to the pump. if necessary, it is possible to provide an alternative live feed to the pump, but ensure that a 20 amp fuse is used, and that there is no possibilty of sparks occurring near petrol.

H 21207

Bridging a relay with a 20A fuse

Fuel system pressure checks The system should provide fuel to the fuel rail and injectors, at a pressure which is constant in relation to manifold pressure. The system consists of a pump, main filter, fuel rail (to distribute the fuel to the injectors) and injectors, which contain a fine filter. To maintain the pressure, a pressure regulator is fitted, which allows excess fuel back to the tank. The regulator is connected to the inlet manifold via a vacuum pipe, in order to adjust the fuel pressure in conjunction with changes in the manifold pressure.

Warning: Before disconnecting any of the fuel lines, it is advisable to disable the fuel

pump and run the engine, to depressurise the fuel system. The fuel pump relay is incorporated in the system relay, preventing the pump supply from being disconnected without disabling the rest of the injection system. It is therefore necessary to independently disconnect the fuel pump electrical connections directly at the pump. Disable the fuel pump and run the engine until it stops, to depressurise the fuel system.

Connect the fuel pressure gauge as indicated in equipment manufacturer's instructions, and connect the gauge either at the fuel inlet connection to the fuel rail, or between the fuel rail and the pressure regulator. Wherever possible, locate a tap between the gauge and the fuel rail. Reconnect the fuel pump, and start the engine (make sure that if a tap is fitted with the gauge, it is in the ‘open’ position). If the engine will not start, crank the engine or bypass the relay, which will allow the pump to operate and provide the required pressure. Note the fuel pressure. Disconnect the vacuum pipe at the fuel pressure regulator, and plug the hole in the pipe. The fuel pressure should increase to the specified value. (During cranking, the engine only produces a low vacuum level, therefore the fuel pressure will be very close to the specified level even if the vacuum pipe remains connected.) Also note that on an engine which is running, the same test can be carried out using a CO reading, which should increase with the fuel pressure in conjunction increases. Note: A/though the system pressure may be correct when the engine is running under workshop test conditions, it does not prove that the pressure and fuel flow are acceptable at high engine speeds and loads. Unless the pressure can be checked with the vehicle on a rolling road, it will be necessary to carry out fuel pump checks to establish whether the pump can supply sufficient fuel at the required pressure when the fuel demand is high.

With the engine running, if the fuel pressure is already at the specified level prior to disconnecting the regulator vacuum pipe, the pressure regulator is likely to be faulty, but ensure that manifold vacuum is available from the vacuum pipe, and that there are no leaks. If the fuel pressure is higher than specified, it indicates a faulty pressure regulator, but it is possible for a blockage on the return line from the regulator to cause a high system pressure. Attach an independent pipe to the pressure regulator on the return pipe connection,

452

Nissan

ECCS

wiring diagram), and carry out relay checks

PRESSURE REGULATOR

if necessary.

FUEL RAIL

EXCESS FUEL RETURN

INJECTOR

FUEL TANK FUEL PUMP Fuel system run the engine, and allow the fuel to drain into a suitable container. If the fuel pressure is now at the specified level, check the vehicle return line for a blockage. If the pressure is still high, renew the regulator. If the fuel pressure is lower than specified, it is possible that the regulator is faulty, but the most likely cause is a faulty fuel pump, or a severe blockage in the fuel filter or supply line. Where possible, with the engine running or cranking, briefly clamp the fuel return line from the regulator. If the pressure now rises substantially, it indicates a regulator fault. If the pressure remains low, carry out fuel pump checks, and also look for a fuel leak between the pump and the regulator.

Fuel pump and filter checks The fuel pump is able to provide the system with a greater quantity of fuel than is required to run the engine. The excess fuel is passed back to the tank via the fuel pressure regulator. The fuel passes from the pump through a main filter before reaching the fuel. rail and injectors. The electrical supply for the pump originates at the relay, and it will only switch on the pump under certain conditions. Crank the engine, and listen for pump operation. If the pump is not running, check for supply voltage to one of the connections at the pump by repeating the cranking test. If the supply voltage is not available, check the wiring through to the relay (refer to the

Check for a good earth on the remaining connection at the pump, and rectify if necessary. If the electrical connections and supply voltage are good, but the pump will not run, it should be renewed. When carrying out system pressure checks, if the pressure is low, or if it is suspected that the pump is failing when the fuel demand is high, it will be necessary to carry out a flow rate and maximum-pressure check. If a pressure gauge and tap can be connected to the system (refer to the first fuel system pressure check), turn the tap to the ‘off’ position, and crank the engine until a maximum pressure reading is reached. The pressure should reach approximately 5 bar (75 \|bf/in?) or more. If the pressure is too low, it indicates a pump fault. It is unlikely that a filter blockage will prevent the pressure from reaching the required level, unless the blockage is very severe. If the maximum pressure is acceptable, it is still advisable to carry out a flow rate check. Disconnect the fuel supply line from the fuel rail, and allow the fuel to drain into a suitable container. The test should ideally be carried out for a period of at least thirty seconds. It will therefore be advisable to bypass the fuel pump relay to allow the pump to run without cranking the engine (refer to ‘fuel pump relay — bypassing’). Run the pump, and note the fuel quantity

delivered,

comparing

with

the

FUEL RAIL

FUEL SUPPLY

H,2/1209 Connecting

a pressure gauge

specified —

value. A low output would indicate a probable pump fault, but a check should be made for blockages in the lines and the filter, as detailed in the following paragraph. Disconnect the fuel supply line from the filter, and repeat the fuel flow rate test by running the fuel directly from the pump to the container. If the flow rate is now close to that specified, renew the filter.

Pressure regulator

Nissan

Crank angle sensor General description The crank angle sensor is located in the ignition distributor. It indicates to the ECU the position of the crankshaft, via the distributor shaft rotation. There are two sets of divisions. One set is divided into 360 reference points, which indicate the position to one degree. The second set indicates a reference to each cylinder. The sensor uses an LED to pick up the reference points, and the signal is then passed to the ECU.

453

ECCS

During rotation, there should be a noticeable volt reading which oscillates between O and 5 volts. If there is no voltage reading, check for a voltage supply to pin 1, and if unavailable, carry out a wiring check (refer to the wiring diagram). Check for continuity from terminal 2 to

earth, and rectify it faulty.

to

prevent

a _ possible

short-circuit

Inertia switch

General description An

inertia

If all the wiring and supply voltages are correct but the sensor is not functioning,

vehicles,

renew the crank angle sensor.

components,

which

switch

is

will

cut

fitted

on

off the

Two relays are used, to provide a switched supply voltage to the injection system and fuel pump. The relays require certain items of electrical information before they will switch on the system components.

supply to the fuel pump, and possibly other in the event of an accident.

If it is apparent that there is no live feed to the pump or other components, locate the inertia switch, and check for continuity between the two terminals. If the switch is open (no continuity), operate the reset button. If the switch is still open, renew it.

Static checks

Crank angle sensor

Static checks Note: These checks are only necessary if the engine will not start, but it is advisable to disable the ignition system to prevent shocks, or to ensure that the engine does not attempt to fire. Connect a voltmeter to terminal 3 and earth, and to terminal 4 and earth individually. Switch on the ignition, and very slowly turn the engine, or alternatively remove the distributor and turn by hand.

Note: Refer to the wiring diagram carrying out the following checks.

some

electrical

Static checks

Relay checks General description

H.21354-

or

damage.

when

If, during any system component checks, it is found that there is no supply voltage available from the control relay, check for continuity from the component to the control relay. Rectify if necessary. If there is no voltage available at the fuel pump, check for continuity to the fuel pump relay, and rectify the wiring if necessary. In either case, remove the relay from the holder, and check for a live feed with the ignition on, or a permanent live feed on the control relay. Bridge the live terminal and the terminal connected to the system component. If the component now functions, suspect the relay, but refer to the wiring diagram and carry out wiring checks. Note: When bridging the two relay terminals, fit a 20 amp fuse in the bridging wire,

H.2/216 Typical inertia switch

ECU

checks — Nissan

ECCS

General It is not possible, without dedicated test equipment, to carry out a direct check on the ECU. It is, however, possible to establish whether or not the ECU is functioning by carrying out the following tests. The tests are divided into two categories — one with the ECU multi-plug connected, and one with the multi-plug disconnected. It

connections to the system components are satisfactory, and that all the relevant signals are being passed from the sensors to the ECU. If the ECU is still not providing the correct output signals to the injectors, then the ECU should be substituted. Warning: Do not disconnect the ECU multi-plug with the ignition

should

switched on.

be

possible

with

these

tests

to

establish

that

all

the

ECU multi-plug terminal

Multi-plug connected (Yes/No)

Test to be carried out

3

Yes

9 34 35 38

Yes Yes Yes Yes

Check connection and primary ignition waveform from ignition coil terminal 1 during cranking, or when running Check connection and voltage from starter circuit during cranking, or when running Check voltage with ignition on : Check connection, and for battery voltage, from main control relay during cranking, or when running Check connection and voltage from throttle position sensor (if fitted) during cranking, or when running

WOT 102103; 104,105,106 114

Yes Yes

Check connection and signal from fuel injectors during cranking, or when running Check for battery voltage (via fuse) during cranking, or when running

1 2 4 6 ih cz 15 16 18 20

No No No No No No No No No No

Check Check Check Check Check Check Check Check Check Check

23

No

Check connection

Fis 26 Zt 28 30 31 36 48 54 and 57 HOF 108 709,712,113 114

No No No No No No No No No No No No No

Check Check Check Earth Check Check Earth Check Check Earth Check Earth Check

connection connection connection connection connection connection connection connection connection connection

to to to to to to to to to to

test terminal idle-up valve EGR system (if fitted) main control relay test terminal airflow meter terminal E fuel temperature sensor auxiliary air valve throttle position switch (if fitted) fuel pump relay ;

to water temperature sensor

connection to throttle position switch (if fitted) connection to airflow meter terminal D connection to main control relay connection connection to airflow meter terminal A connection to airflow meter terminal B connection connection to throttle position sensor (if fitted) connections to throttle switch (if fitted) connection connection to fuel pump and relay connection for battery voltage (via fuse)

455

Fault diagnosis — Nissan ECCS Test components in the order given alongside specific faults

o

hm ra

3

fe) 2

”

1

ro)

=

®

GC

Se

he

a) ro)

®

7)

5

”

ge

LS

0 —

ae

$

a

ee

§

r.

“es

aS

dora

bans-2

Poor hot starting

........::ceceeee

7

at

5)

hil2? 7

ia)

...........cccsseeeeeeeees

ao =

&(e)

~

—

o

Z

es

oy

i

he

3

”

66

he control speed idle valve air Auxiliary or

Zest

eR

°

SyOo

day position crankshaft and relay signal Ignition to pee

wn a

me

—_

Te

Bite

5

3 4°

3

Ai

Leo

5

4

6

*

2

4

Z

7

4

2

7

a

2

7

3

‘aoaiiin,

nO

5

2

7

ae

=

6

Z

7

2

cE

5

eecl

es

ected. ns dese abs sie cseccces

Low CO at idle (adjuster INT IGCTIVG ects cek eles case creesss

2.

ET A

........:.::0

rieee nentasence FiERTTOCTIVE Jeace

re)

°

”

E

Poor cold starting

High CO at idle (adjuster

Pa

2.

(PROT

ence eee .......eeeeeeee

® =

7

a

..............

Excessive fuel CONSUMPTION

re

S

‘oe

Unstable idle

©

ro)

+

g ©

=

me)

a

sete cas Gevess [AIS TOD-SlOW pong. peewee

~-~

£he ®

)

ldlG TOO TASTE

©

=e = ~ DOr

*¥O

Flat spot under ACCOIOFALION .ccsceceescdedeserdenstes

)

=

—

facts 5 alae roel

&

ciicscccescledescedsssi>

7

oSOo ae© 6-2

Sete

LOSS OF POWE!

=

a

eee eee eeCe

foe

2

Engine will not start

7

=

6

6

5

4

5s 4

7

3

6

i

Nissan

Main

control

relay

Fuel pump

ECCS

relay

To fuel pump

Terminal

20 ECU

~ itz

es cel

tee ees Be:

Test terminals

Paps: base

Airflow meter/MAP sensor

39 436 2S 69 667

< 30°C/86°F

9 to 10

Test terminals

ohms

6&8

130 to 210

a7

7&6

Fuel system checks Fuel pressure - regulator vacuum pipe disconnected - bar (Ibf/in2) ..............

2.5 (36) nominal

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

ohms

W & Switch body

Similar to, or above, idle values

eee Ee

SOT

H. 21206

Up to 1000

NISSAN

Nissan

EFI

280 ZX 79 to 84

Airflow sensor MAP sensor }

25esU

a

a|

Throttle position switch/sensor

Auxiliary air valve Idle speed control valve Injectors Thermotime switch ECU (in footwell) Water temperature sensor ARWBH™ OANA 70 Air temperature sensor 771 Pressure regulator 72 Relays 73 Cold start injector 14 Warm-up regulator 15 Vacuum/pressure switch 16 Fuel filter 17 Metering head 18 Injector resistors 19 Load enrichment device 20 Additional idle control valve

ZaJ

et:

Not all items fitted to all models

119

SEE:

1/10

H.19341

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

and run it for Ensure the engine is at normal operating temperature, ng the idle adjusti before rpm 2000 at s second approximately twenty throttle body, and speed. Locate the idle bypass adjuster ‘1’ on the in the adjuster to Screw remove the tamperproof plug (where fitted). e the speed. increas to r adjuste the w decrease the idle speed, or unscre iate. appropr where plug proof Fit a new tamper

2

CO

(mixture) adjuster screw

at Ensure the engine is at normal operating temperature, and run it engine the With seconds. twenty around for rpm 2000 approximately at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either CO, an Allen key or screwdriver, screw in the adjuster to increase the to reading CO the Set level. CO the reduce to adjuster the unscrew or plug. that specified, and fit a new tamperproof

462

Nissan

NISSAN

Silvia 2.0 ZX DOHC

EFI

Refer also to page 39

84 to 86

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)...........

S00 = 50

Injectors (ohms) 3:44... 72... ...

2.10.3

Cold start injector (ohms)

4

.......

Auxiliary air valve (ohms)........

CO at tale (26) acco. SYS SPS

1.0 max

CO at 3000 rpm (%).......

20

> 1s

SOOO Kany aac cease

W & Switch body

< 30°C/86°F

Similar to, or above, idle values 2.5

SAS

Throttle position switch/sensor

degrees

Granking «.. Bon. ssp abe

oa ee

Test terminals

Large duration

Engine cold:

Le

Auto idle speed control valve

Me

Airflow meter/MAP sensor

SSO Om on Ou aezy,

Fuel system checks Fuel pressure - regulator vacuum

pipe

disconnected - bar (Ibf/in?) ..............

2.5 (36) nominal H.21206

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

Oto

10

Test terminals

ohms

6&8

130 to 260

Vitam)

Up to 1000

NISSAN

Nissan

ECCS

Silvia 2.0 ZX DOHC 84 to 86

13. 11 Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve

/njectors Thermotime

switch

ECU (in passenger footwell) Water temperature DANDANRWBH™

sensor

10 Air temperature sensor 771 Pressure regulator 72

Relays

73 14 75 16 717 78 79 20

Cold start injector Warm-up regulator Vacuum/pressure switch Fuel filter Metering head /njector resistors Load enrichment device Additional idle contro! valve

Not all items fitted to all models

H.19362

CO (mixture) adjustment

Idle speed adjustment

1

Idle bypass adjuster screw

run it for Ensure the engine is at normal operating temperature, and the idle ng adjusti before rpm 2000 at approximately twenty seconds and body, throttle the on ‘1° adjuster bypass idle speed. Locate the to adjuster the in remove the tamperproof plug (where fitted). Screw speed. the increase to adjuster decrease the idle speed, or unscrew the Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

at Ensure the engine is at normal operating temperature, and run it engine the With seconds. twenty around approximately 2000 rpm for airflow at the correct idle speed, locate the CO adjuster ‘2’ on the meter, and remove the tamperproof plug (where fitted). Using either CO, an Allen key or screwdriver, screw in the adjuster to increase the to reading CO the Set level. CO the reduce to or unscrew the adjuster plug. roof tamperp new a fit and , specified that

Nissan

EFI

Contents

INJECTION Signal ANd CULAatiON .....c.cseccdesedeveeeendfooee eee: 5s MUERTE UTES TTY: SOTEN AO oir acaeennanatiavennsresie SEN. sock TMR@tTe OSITION’ SWITCH, coc nccocece-:-c-cetetetsscbase tees seenMega eee SuieilarVedih VaIWG xu ieeeac.o eee sre costes. & Auxiliary meter and air temperature sensor ....... ees. | Water temperature SENSOF ............sssscsesssseccsenseesess Seer ee 8 |

Injection signal and duration General Wherever possible, it is advantageous to check for an injection signal and the duration as a first test. In many cases, this will provide a good indication of possible faults in the electrical/electronic operation of the system. Refer to Chapter 2 for instructions on how to check for injection signal and duration.

H. 2/200 Injection waveform

Dynamic checks To obtain an injection signal (unless the test equipment is supplied with an adapter), it is usually easiest to roll back the rubber protection boot on one of the injectors, and touch the test lead to each of the two terminals separately until a signal is obtained. Alternatively, gain access to the ECU terminals with the multi-plug still connected, and refer to the wiring diagram for the appropriate terminals to connect to, to obtain the injection signal.

On an engine which will not start, always

464 464 464 465 465 467

[A SCLONS/ EL. Lae eh cd ee ee Fuel system pressure and fuel pump CheCKS ........cccccecceseeeeeeee Cold start injector and thermotime SWItCH ........cccccccsccscessceseeeee Metta. SWttC Diese Bode oP ensconced hasaes beech ode ENA Cae Ot ee el a ECU

467 468 470 470 470

checks, fault diagnosis and wiring diagrams

check the operation of the ignition system first. The injection system relies on a signal from the ignition system, and will therefore not function if the ECU does not receive an ignition pulse. Check for an injection signal. If there is no signal available at all, refer to the injector checks. If an injection pulse is available, check the duration. If the engine is cold, and the pulse is too small, or if the engine is hot, and the pulse is too large, refer to the water temperature sensor checks. Also refer to the airflow meter checks. If the engine does run, again check the duration cold and hot, and if it is incorrect, refer to the checks as detailed above. If the engine is already hot, refer to the water. temperature sensor checks for details of the water temperature simulation test. Check for an increase in the duration during a snap acceleration test, and if it is not acceptable, refer to the airflow meter checks. Also check for injection cut-off during deceleration (where used), and if it is not functioning, check the throttle position sensor. If the above checks appear to provide acceptable results, this generally indicates that the electrical system is satisfactory. If there still appears to be an injection system fault, carry out the fuel pressure checks before any detailed electrical component checks are carried out.

Throttle butterfly setting The throttle linkage and throttle butterfly are factory-set, and should not normally be adjusted. If it is necessary to check or adjust the butterfly closed position, the following procedure can be used. Slacken off the throttle linkage stop screw on the throttle body until there is a small air gap. Screw the stop screw in an additional half-turn. This should result in an air gap of approximately 0.05 to 0.15 mm (0.002 to C.006 in) between the throttle butterfly and

H.21205 Throttle butterfly air gap (typical)

the throttle casing. On vehicles that do not have an automatic idle speed control, with the idle bypass screw fully closed, the idle speed will typically be around 600 to 650 rpm with the correct butterfly air gap. After setting the butterfly, check the Operation of the throttle position switch or sensor.

Throttle position switch General description The throttle position switch indicates to the ECU idle and full-load positions, via two sets of contacts in the switch body. When neither of the two switched positions is indicated, a part-load condition is assumed. Mixture strength is dependent on the switch position, and automatic idle speed control valve operation (where fitted) and deceleration fuel cut-off are implemented when the idle position is indicated.

Static checks Either during cranking or with the engine running, check for battery voltage to the centre wire of the connector plug (switch terminal 30) either by disconnecting the plug from the switch, or by rolling back the rubber protection boot. The supply voltage

465 Nissan

EFI

up, the valve progressively closes, reducing the idle speed to normal. The valve remains

open (fast idle) until a combination of engine heat and electrical heating force it to close.

by a faulty electrical

circuit to the heating

element.

With the plug disconnected, check for the specified

across

element

the valve

resistance

terminals.

by measuring

If the

indicates a short- or open-circuit, valve.

reading

renew the

With the plug disconnected, check for battery voltage (engine running or cranking) at one of the plug terminals. The voltage supply originates from the control or

system relay (refer to the wiring diagram). If there is no voltage supply at the relay, carry out relay checks.

HEZAISLE Throttle position switch originates from the control or system relay (refer to the system wiring diagram). The remaining two terminals are connected to the ECU — terminal 29 for idle position, and terminal 24 for full-load position. With the plug disconnected and the throttle closed, check for continuity between the centre terminal and terminal 29 of the switch. If it is open-circuit, slacken the securing screws, and rotate the switch until continuity exists. If there is still no continuity, renew the switch. Check that the idle contacts open when the throttle is opened. Note: Jhe throttle butterfly adjustment should be correctly set before adjusting the idle position switch. Check for continuity between the switch centre terminal and terminal 24 with the throttle fully open. If there is no continuity renew the switch. Check that the full-load contacts are open when the throttle is closed.

AH2/200

Auxiliary air valve

Dynamic checks Engine cold Where possible, clamp shut one of the two air hoses* connecting the air valve to the induction system. If the valve is functioning, the idle speed will drop. If there is no drop in the idle speed, this indicates faulty valve operation. Engine warm Where possible, clamp shut one of the two air hoses* connecting the air valve to the induction system. If the idle speed drops, it indicates faulty valve operation. If there is no drop in idle speed, this indicates correct valve operation. *Note: /f it is difficult to clamp an air hose for either of the above tests, one of the hoses should be disconnected, and both openings blanked off. Restart the engine, and note whether the speed is the same or reduced. The same conclusions can be drawn as for tests with the hoses clamped.

Static checks

Throttle position switch terminals

Auxiliary air valve

General description The auxiliary air valve provides a fast idle when the engine is cold, and during the initial warm-up period. As the engine warms

With the ignition off, check for a good earth connection to the remaining terminal on the connector plug. An alternative test can be carried out by independently supplying battery voltage and an earth connection to the valve terminals. The valve should completely close within three to four minutes. If the valve does not close, cleaning with a suitable solvent may effect a cure, otherwise the valve should be renewed.

Disconnect the two air hoses from the valve body, and examine the opening of the valve port, either by using a mirror if necessary, or by removing the valve from the engine. The valve should be open if the engine is cold, and closed if the engine has been running for more than five minutes. A valve that has stuck open or closed may benefit from cleaning with a_ suitable solvent. If a valve still remains closed after cleaning, it will probably need renewing. When a valve remains open, it may be caused either by a broken heater element, or

Airflow meter and air temperature sensor

General description The airflow meter indicates to the ECU the variation in airflow to the engine. Incorporated into the airflow meter is the air temperature sensor, for fine-tuning the mixture strength.

Dynamic checks An indication of poor airflow meter response can be obtained by checking the injection duration. Note the duration at 2000 rpm, and again during snap acceleration. If there is no substantial increase in duration, it usually indicates an airflow meter fault. Alternatively, gain access to the airflow meter flap by disconnecting assembly from air filter. With the electrical connector and remaining intake trunking still connected, run the engine at around 1200 rpm. Note the injection duration or exhaust gas CO reading, and slowly push open the airflow meter flap (also check for a sticking flap). The duration and the CO level should increase, and it is likely that the engine will flood. If the increase in readings does not occur, or the flap is sticking, continue with the following checks. Preferably using the low-voltage facility of an oscilliscope, or a digital voltmeter, check the output voltage from the airflow meter on terminal 7. To gain access to the terminal, roll back the rubber protection

466

Nissan

EFI

/

Condition

Typical voltage

Cranking (throttle closed) Normal idle Fast idle 3000 rpm Snap open throttle

3to4

(V)

4.5to5 51D 6 to 7 Up to 8

If there is no voltage reading, or if the voltage change is erratic, refer to the static checks. Connect the test lead to pin 27, and note the voltage reading with the engine cranking or running. A typical reading is approximately 7 to 10 watts, depending on the ambient air temperature. If the reading is incorrect, refer to the static tests.

PARTIALLY OPEN

Static tests

H.212/4 CLOSED Auxiliary air valve ports

boot from the airflow meter connector, and locate the wire corresponding to terminal 7. With the connector in place, crank, or where possible run, the engine. Connect the oscilloscope or volt test lead to the exposed terminal connection, and note the voltage. With the engine running, slowly open the throttle and note the progressive increase in voltage. A delay in the increase, or no increase at all, usually indicates a sticking flap in the airflow meter. In most cases, this can be cured by cleaning. An erratic change in voltage, or hash on the oscilloscope trace, often indicates a fault in the resistance track, and this is not normally serviceable. Also

check for a voltage increase throttle is snapped open.

when

the

Disconnect the connector plug from the airflow sensor, and check the resistances across the airflow meter terminals, as indicated in the Specifications. Note the resistance values, and compare against those specified. A reasonable tolerance is indicated by the specified values, but a fault is usually indicated by an open- or shortcircuit. When checking between terminals 6 and 7, gain access to the airflow meter flap, and slowly push it open to its limit. The re-

AH. 2/203 AH2/20/

Airflow

meter

Moving airflow meter flap

Nissan

sistance reading will increase and decrease in a series of steps. A fault will normally be indicated by an open-circuit at some stage during the flap movement. Also check for mechanical

resistance

as

the

flap

moved,

especially near the closed position. A sticking flap can often be cured by cleaning, but, if not, the assembly should be renewed. The

air

temperature

sensor

duration on a cold engine should provide a large duration, which should reduce as the engine warms up. If the engine will not start,

the duration can be checked during cranking, but note that the first few moments may provide a higher duration reading than specified.

resistance

reading between terminals 6 and 27 will depend on the ambient air temperature. If a resistance reading within the highest and lowest specified values is obtained, it is unlikely that a fault exists. Checks can, however, be carried out by warming or cooling the air temperature sensor* and noting the resistance changes.

6°98

7 27

Water temperature sensor Plug terminal is blue or white

The water temperature sensor provides a varying voltage signal to the ECU to indicate engine coolant temperature. This enables mixture correction to take place in response to engine temperature changes.

Pull off the sensor connector plug, and measure the resistance across the sensor terminals, comparing the readings with those specified. If the sensor is not removed from the engine, it is advisable to take measurements with the engine cold, and then with it hot, to establish the change in resistance in conjunction with the change in temperature. The sensor can, however, be removed and tested in water at various temperatures. If the sensor resistances are correct, check the connections and the continuity of the wiring from the two sensor plug terminals to the ECU and earth (refer to the wiring diagram).

Dynamic checks

Water temperature simulation test

meter terminals

Water temperature sensor General description

Carry out an injection duration check, and refer to the specified readings. Checking the

a hot-engine

injection duration, which should be close to the specified reading for a warm engine. Switch the ignition off, and remove the wire

or

resistor.

Either

leave

the

Injectors

Static checks

Airflow

This will provide

H. 2/204

During cranking or running, a substantially smaller than specified duration when cold, or a substantially larger duration when hot, indicates a probable sensor or sensor circuit fault, but refer to the water temperature simulation test.

H. 21206

300 ohms.

simulation. Crank, and if possible, start the engine (run at 1500 rpm), and note the

plug terminals unconnected, or preferably, bridge with a resistor of approximately 6 Kohms or more, to simulate a cold engine. (This simulation can cause extreme flooding of the engine, preventing starting.) Repeat the test, which should now provide a noticeably larger duration than for the hot-engine simulation. The duration reading should be close to, or greater than, the specified value for a cold engine. If the engine fails to start due to flooding, this indicates correct ECU response. If, during the simulation tests, there is no noticeable difference in the duration measurements, check the sensor plug and wiring for continuity to the ECU terminal and to earth (refer to the wiring diagram). If there is no wiring fault, suspect the ECU.

If, during the dynamic checks, there is a zero volt reading, carry out the first static check, but also check for a supply voltage to terminal 9 on the airflow meter connector, with the engine cranking or running. Also check for continuity of the wiring from connector plug terminals 6, 7, 8 and 9 to the relevant pins on the ECU (refer to the wiring diagram). The terminals which correspond foo 7 o and 9 are 34, 32, 33.and 35 respectively.

Beso

sensor, and bridge the connector plug terminals with a suitable piece of wire, or preferably, a resistor of approximately 200 to

bridging

* Warning: Do not use a naked flame to warm the air temperature sensor.

Note: F/ectrica/ faults in the airflow meter are not normally serviceable.

467

EFI

With the engine switched off, pull off the connector plug from the water temperature

General description The injectors receive a live feed from the control relay, via a set of ballast or power resistors (one for each injector). The injectors are switched on and off on the earth circuit, via independent connections through the ECU.

Dynamic checks Crank or run the engine, and listen to each injector for a clicking sound as the injector operates (it may be necessary to use a suitable listening device, such as a screwdriver, as a ‘stethoscope’). If it appears that one or more injectors are not functioning, carry out the following checks. Check the injection signal and duration, and if correct, carry out the static injector checks. If there is no injection signal, check for supply voltage from the power resistors, and if necessary from the control relay to the resistors. Refer to the relay checks Section if the relay is not supplying voltage to the resistors, or renew any faulty resistors if necessary. Check the continuity of the wiring from the injector plugs to the ECU multi-plug connector — disconnect all other system connector plugs, and refer to the wiring diagram.

468

Nissan

EFI

locate the terminal on the relay holder that is permanently live. Bridge the live terminal to the fuel pump wire, which will then run the pump. The bridging wire should be fitted with a 20 amp fuse to protect against a possible short-circuit.

Due to the variations that exist in the wiring colours, it will be necessary to check for

continuity

between

the

relay

holder

terminals and the fuel pump, to establish which of the relay terminals connects to the pump. If necessary, it is possible to provide an alternative live feed to the pump, but ensure that a 20 amp fuse is used, and that there is no possibilty of sparks occurring near petrol.

AH. 2/202

Connection to an injector

If the injection signal exists, but the duration appears to be incorrect, or if supply voltage is correct, and there is still no injection signal, refer to the ECU checks for a guide to further tests.

H 21207

Static checks Remove the connector plug from the injector(s), and check the resistance across the two injector terminals, comparing with the reading specified. Also ensure that there is nO continuity between the injector body and the injector terminals. Note: /f there is no fault found during the above checks, but it is apparent that one or more injectors are not functioning correctly, it is probable that fouling exists in the faulty injectors, and a flow rate test may be required — refer to Chapter 2.

Fuel system

pressure and fuel

pump checks Fuel pump relay — bypassing For a number of the following tests, it is necessary to crank the engine in order to allow the pump to run. It is possible to bypass the pump relay, which will allow the pump

to run without cranking.

Locate the control relay, which also acts as the pump

relay.

Remove

the relay, and

Bridging a relay with a 20A fuse

Fuel system pressure checks The system should provide fuel to the fuel rail and injectors, at a pressure which is constant in relation to manifold pressure. The system consists of a pump, main filter, fuel rail (to distribute the fuel to the injectors) and injectors, which contain a fine filter. To maintain the pressure, a pressure

regulator is fitted, which allows excess fuel back to the tank. The regulator is connected to the inlet manifold via a vacuum pipe, in order to adjust the fuel pressure in conjunction with changes in the manifold pressure. Warning: Before disconnecting any of the fuel lines, it is advisable to disable the fuel pump and run the engine, to depressurise the fuel system. The fuel pump relay is incorporated in the system relay, preventing the pump supply from being disconnected without disabling the rest of the injection system. It is therefore necessary to indepen-

dently disconnect the fuel pump connections directly at the pump.

electrical

Disable the fuel pump and run the engine until it stops, to depressurise the fuel system. Connect the fuel pressure gauge as indicated in equipment manufacturer's instructions, and connect the gauge either at the fuel inlet connection to the fuel rail, or between the fuel rail and the pressure regulator. Wherever possible, locate a tap between the gauge and the fuel rail. Reconnect the fuel pump, and start the engine (make sure that if a tap is fitted with the gauge, it is in the ‘open’ position). If the engine will not start, crank the engine or bypass the relay, which will allow the pump to operate and provide the required pressure. Note the fuel pressure. Disconnect the vacuum pipe at the fuel pressure regulator, and plug the hole in the pipe. The fuel pressure should increase to the specified value. (During cranking, the engine only produces a low vacuum level, therefore the fuel pressure will be very close to the specified level even if the vacuum pipe remains connected.) Also note that on an engine which is running, the same test can be carried out using a CO reading, which should increase in conjunction with the fuel pressure increases. Note: A/though the system pressure may be correct when the engine is running under workshop test conditions, it does not prove that the pressure and fuel flow are acceptable at high engine speeds and loads. Unless the pressure can be checked with the vehicle on a rolling road, it will be necessary to carry out fuel pump checks to establish whether the pump can supply sufficient fuel at the required pressure when the fuel demand is high. With the engine running, if the fuel pressure is already at the specified level prior to disconnecting the regulator vacuum pipe, the pressure regulator is likely to be faulty, but ensure that manifold vacuum is available from the vacuum pipe, and that there are no leaks. If the fuel pressure is higher than specified, it indicates a faulty pressure regulator, but it is possible for a blockage on the return line from the regulator to cause a high system pressure. Attach an independent pipe to the pressure regulator on the return pipe connection, run the engine, and allow the fuel to drain into a suitable container. If the fuel pressure is now at the specified level, check the vehicle return line for a blockage. If the pressure is still high, renew the regulator.

469 Nissan

EFI

low, it indicates

PRESSURE REGULATOR

that

filter

a pump

blockage

fault. It is unlikely

will

prevent

pressure from reaching the reqvired unless the blockage is very severe.

FUEL RAIL

EXCESS FUEL RETURN

a

the level,

If the maximum pressure is acceptable, it is still advisable to carry out a flow rate check.

Disconneet

the fuel supply line from

the fuel rail, and allow the fuel to drain into a suitable container. The test should ideally be

carried out for a period of at least thirty seconds. It will therefore be advisable to

INJECTOR

bypass

FUEL TANK FUEL PUMP Fuel system

If the fuel pressure is lower than specified, it is possible that the regulator is faulty, but the most likely cause is a faulty fuel pump, or a severe blockage in the fuel filter or supply line. Where possible, with the engine running or cranking, briefly clamp the fuel return line from the regulator. If the pressure now rises substantially, it indicates a regulator fault. If the pressure remains low, carry out fuel pump checks, and also look for a fuel leak between the pump and the regulator.

the

fuel

if necessary.

.

Check for a good earth on the remaining connection at the pump, and rectify if necessary.

relay

to

allow

FUEL RAIL

FUEL SUPPLY

H.21209

Fuel pump and filter checks The fuel pump is able to provide the system with a greater quantity of fuel than is required to run the engine. The excess fuel is passed back to the tank via the fuel pressure regulator. The fuel passes from the pump through a main filter before reaching the fuel rail and injectors. The electrical supply for the pump originates at the relay, and it will only switch on the pump under certain conditions. Crank the engine, and listen for pump operation. If the pump is not running, check for supply voltage to one of the connections at the pump by repeating the cranking test. If the supply voltage is not available, check the wiring through to the relay (refer to the wiring diagram), and carry out relay checks

pump

the

pump to run without cranking the engine (refer to ‘fuel pump relay — bypassing’). Run the pump, and note the fuel quantity delivered, comparing with the specified value. A low output would indicate a probable pump fault, but a check should be made for blockages in the lines and the filter, as detailed in the following paragraph. Disconnect the fuel supply line from the filter, and repeat the fuel flow rate test by running the fuel directly from the pump to the container. If the flow rate is now close to that specified, renew the filter.

Connecting a pressure gauge

If the electrical connections and supply voltage are good, but the pump will not run, it should be renewed. pressure system out carrying When checks, if the pressure is low, or if it is suspected that the pump is failing when the fuel demand is high, it will be necessary to carry out a flow rate and maximum-pressure check. If a pressure gauge and tap can be connected to the system (refer to the first fuel system pressure check), turn the tap to the ‘off’ position, and crank the engine until a maximum pressure reading is reached. The pressure should reach approximately 5 bar (75 Ibf/in?) or more. If the pressure is too

AH.2/204

Pressure regulator

470

Nissan

Cold start injector and thermotime switch General description The cold start injector is used during cranking only, to aid the initial starting phase. During cranking, the cold start injector is switched

on

by a thermotime

switch

(located in the cooling system). The thermotime switch will allow the injector to operate when the water temperature

is below

a

predetermined

value.

During cranking, voltage is also supplied to a heating element in the switch, causing the switch to break the cold start injector earth circuit. The thermotime switch can switch off the injector almost immediately, or after as long as eight to twelve seconds, depending on the initial water temperature. Note: 7he predetermined temperature, and the maximum time taken for the heater to open the contacts, are stamped on the thermotime switch body.

EFI

injector, and crank the engine. Check for battery voltage to one of the two terminals on the plug. If there is no voltage, check through the wiring back to the starter circuit. Disconnect the thermotime switch plug, and check for continuity between the live terminal on the injector plug and one of the two terminals on the thermotime switch plug. Also check for continuity on the remaining injector plug terminal to the remaining thermotime switch terminal. Rectify as necessary. With the plug still disconnected, check the specified resistance across the two injector terminals. A short- or open-circuit indicates a faulty injector. Examine the plastic top of the thermotime switch with the plug disconnected. There should be letters corresponding to the two terminals, typically, ‘G’ and ‘K’ or ‘W’. Check the resistance between ‘K’ or ‘W’ and earth.

terminal ‘K’ or ‘W’ and earth. There should now be an open-circuit reading. If the switch remains closed (zero ohms), renew It.

Remove the injector from the intake manifold, and connect all fuel and electrical connections. Crank the engine (ensure that the temperature is below the predetermined level) and check for a wide conical spray pattern. A poor pattern would indicate the need for injector cleaning or renewal. No injection at all would indicate a faulty injector, but first check for acceptable fuel pressure.

Inertia switch

General description An inertia switch is fitted on some vehicles, which will cut off the electrical supply to the fuel pump, and possibly other components, in the event of an accident.

Static checks If it is apparent that there is no live feed to the pump or other components, locate the inertia switch, and check for continuity between the two terminals. If the switch is open (no continuity), operate the reset button. If the switch is still open, renew it.

A.H.21213 Thermotime

switch

Plug terminal is brown

H.212/12

Cold start injector

Static Checks Prevent the engine starting by using the ‘engine-kill’ facility on the test equipment, or by disabling the fuel pump (refer to the fuel system pressure and pump checks). Ensure that the water temperature is below the predetermined level — if necessary, remove the thermotime switch and place it in cold water. Disconnect the plug from the cold start

The reading should be zero ohms if the temperature is below the predetermined value. If the temperature is above the predetermined value, there should be an open-circuit or infinity reading. If readings are incorrect, replace the thermotime switch. Test the heating element by checking for a resistance between ‘G’ and earth. The exact reading will depend on the type of switch fitted, but if a zero ohm or open-circuit reading Is obtained, renew the switch. Carry out the remaining checks detailed below. Ensure that the temperature is below the predetermined level, reconnect the plug, and crank the engine. The engine should be cranked for a period equivalent to the time value stamped on the switch body. Immediately disconnect the switch plug, and check the resistance between the switch

H.2/216 Typical inertia switch

Relay checks

General description Two relays are used, to provide a switched supply voltage to the injection system and fuel pump. The relays require certain items of electrical information before they will switch on the system components.

Nissan

471

EFI

EE

8

Static checks Note: Refer to the wiring diagram carrying out the following checks.

when

If, during any system component checks, it is found that there is no supply voltage available, refer to the wiring diagram to check where the feed originates, for example, the ECU or fuel pump relay. If the feed originates from the ECU, check the wiring to the relevant ECU terminal. If the wiring is

Main

relay

If there is no voltage available at the fuel pump or the auxiliary air valve, check for

good, but there is no available voltage, check for a live feed to the ECU terminal 27 with the ignition on. If there is no voltage available at terminal 27, check for continuity from terminal 27 to one

of the

control

relay

terminals.

continuity of the wiring from the auxiliary air valve through to one of the relay terminals. If the wiring is good, suspect the pump

wiring is good, suspect the relay, but check for a permanent live feed to one of the terminals, and a second feed to the relay when the ignition is switched on. The remaining terminal should be connected to earth.

is available from terminal 13 to the relay. The

remaining relay terminal should be connected to earth.

Fuel pump relay

!

Live feed to fuel pump, auxiliary air valve Earth connection

Terminal 13 ECU Battery

+ve

(fused 10 amp)

CX Live feed to terminal

©

27 ECU

Earth connection

O Live feed from ignition switch O

H. 2/340

Relay wiring diagram

Battery

relay,

but check for a live feed to one of the terminals when the ignition is switched on. Also check that during cranking, a live feed

If the

+ve

ECU

checks — Nissan

EFI

General It is not possible, without dedicated test equipment, to carry out a direct check on the ECU. It is, however, possible to establish whether or not the ECU is functioning by carrying out the following tests. The tests are divided into two categories — one with the ECU multi-plug connected, and one with the multi-plug disconnected. It should be possible with these tests to establish that all the

ECU multi-plug terminal

Multi-plug connected (Yes/No)

Test to be carried out

2 a 4, 6 y 8 18 26 27, a2 33 34 35

Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes

Check Check Check Check Check Check Check Check Check Check Check Check Check

connection connection connection connection connection connection connection connection connection connection connection connection connection

13 14 15,1 9;20 21 24 25 29 30

No No No No No No No No

Check Check Earth Check Check Check Check Check

connection connection connection connection connection connection connection connection

and and and and and and and and and and and and and

connections to the system components are satisfactory, and that all the relevant signals are being passed from the sensors to the ECU. If the ECU is still not providing the correct output signals to the injectors, then the ECU should be substituted. Warning: Do not disconnect the ECU multi-plug with the ignition switched on.

signal to injector no 1 during cranking, or when running signal to injector no 5 during cranking, or when running signal to injector no 3 during cranking, or when running signal to injector no 2 during cranking, or when running signal to injector no 4 during cranking, or when running signal to injector no 6 during cranking, or when running primary ignition waveform during cranking, or when running voltage to cold start injector during cranking, or when running voltage from main control relay during cranking, or when running voltage from airflow meter terminal 7 during cranking, or when running voltage from airflow meter terminal 8 during cranking, or when running voltage from airflow meter terminal 6 during cranking, or when running voltage from airflow meter terminal 9 during cranking, or when running

to fuel pump relay and voltage to water temperature sensor to to to to to

auxiliary air valve throttle position switch airflow meter terminal 27 throttle position switch throttle position switch

473

Fault diagnosis — Nissan

EFI

Test components in the order given alongside specific faults

£ O

=

is

: E

EO LE 5 = g

c




ro

=

@

22

es

ty ee

2

4

3

&

=

i

~~)

a

$$

»

=

fe)

Tne

ie

a

2

0

==

—_

&

8

ee 5

7

>

3

4

a)

7

4

a

4

i

5

4

6

4

e)

aoe

)

7

6

q

4

5

6

3

4

. 7

he

7

3

6

474 Nissan

EFI

Injection ECU

©

Water temperature

Throttle switch

sensor

Earth connection

Airflow meter

H. 2/34/

Nissan

EFI wiring diagram

Injection ECU

Battery

+ve

(fused)

Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4

Cylinder 5

Cylinder 6

Fuel injector resistors

Injectors

Nissan EFI wiring diagram

4.21342

Apes

475 eet Std |. ly ee

eS a ke

Injection ECU

O Fuel pump

O

relay

Earth connection

O Starter circuit

Auxiliary air valve

Thermotime

switch

Cold start injector

H. 21343

Nissan

EF! wiring diagram

eee [=la [Se 1905

20)

2279

aee

ele 225

23.

24-25)

1

|=[eH

26

ECU

2708

25)

terminals

S30

Sill

a2)

33)

18;

ISTH TI 34595

through

body

476

RENIX INJECTION

Renault 21 & Savanna

Refer also to page 39

RX, TXE, GTX & Ti 86 to 89; 21 Turbo 88 to 89; 25 TX 87 to 89; Espace TXE & 2000-1

88 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

N/A

AT = Auto

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks Resistance characteristics

Basic checks

775 + 50N 800 + 25 N (R21 Turbo)

Idle speed (rpm)

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%) 1 + 0.5 (R21 non Turbo, Espace)

Water temperature sensor:

Ae

(between terminals)

10. (50) 20 (68) 80 (176)

Ita

ohms

Air temperature sensor:

Gacr)

ohms

(between terminals)

OFN32) 20 (68)

260 000 290 000

5000 2500 300

CO at 3000 rpm (%) HC at idle (ppm)

Injection duration checks Refer to Chapter 2 Injection waveform

Auto idle speed control valve

Test terminals 3&4 Sino 445

ohms

4.21200

Bast!

Small duration

Engine cold:

Large duration

ms

%

degrees

H.21203

Paes oolBoe!

0 to 10

2 ao"

Infinity

ZEST

Infinity

So

1387

0 to 10

Similar to, or above, idle values

2S)

4.64

4.16

ms

%

degrees

Thermotime

switch

Test terminals

ohms

Similar to, or above, idle values

28

3.06

PTBe

Ded

3.66

aed

Ze1

7.00

6.30

2.0

S99

9.00

2 a5

ei22

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal 2.2 (3.9) nominal

Airflow meter/MAP

sensor

Test terminals

Refer to test procedures

477

Renault 21 & Savanna

RENIX INJECTION RX, TXE, GTX & Ti 86 to 89; 21 Turbo 88 to 89; 25 TX 87 to 89; Espace TXE & 2000-1

88 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve Idle speed contro! valve Injectors Thermotime switch EGY Water temperature sensor OANDARWBNH™ Air temperature sensor

Pressure regulator Relays

Cold start injector Warm-up regulator Vacuum/pressure switch Fuel filter (near fuel tank) Metering head Injector resistors Load enrichment device Additional idle control valve H.2/096

Not all items fitted to all models

CO (mixture) adjustment 2

CO (mixture) adjuster screw

H.19432

Idle speed adjustment The engine is fitted with an automatic idle speed control, and speed should not require any service adjustment. If there is an idle problem, refer to the throttle position switch and idle speed control test procedures.

CO (mixture) adjustment Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the remote CO adjuster. Remove the tamperproof plug, and adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof plug after adjustment.

478

Renault

RENIX

INJECTION

Refer also to page 39

25 GTX 8&4 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+t = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

800 + 25 N (except early models)

Injectors (ohms)

Cold start injector (ohms) Auxiliary air valve (ohms) CO at idle (%)

1.5 te 2.5

Water temperature sensor:

ohms

5000 2500 300 CO at 3000 rpm (%) eae

opm

Air temperature sensor:

ohms 260 000

Injection duration checks

290 000

Refer to Chapter 2

Injection waveform

Auto idle speed control valve

4.21200

ed

Small duration

Engine cold:

%

3&4

20

a & 5

40

4&5

20

ohms

199

2 & 18*

0 to 10

3 & 18*

Infinity

2

18ST

Infinity

3 & 18Ff

0 to 10

Thermotime switch

Test terminals

ohms

Airflow meter/MAP sensor

Test terminals

ohms

Large duration

ms

_‘[Test terminals

degrees

et

RA

TN

Similar to, or above, idle values 3.5

4.64

4.16

ms

%

degrees

H.21203

Similar to, or above, idle values

2.3

3.06

20S

1000 rpm

22

3.66

3.29

2000 rpm

Ze

7.00

6.30

2.0

299

9.00

> 25

> 22

Snap open throttle

Fuel system checks Fuel pressure - regulator vacuum disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal

2.2 (3.9) nominal

Refer to test procedures

Renault

RENIX INJECTION

25 GTX 84 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve

/njectors Thermotime switch EGY Water temperature sensor AARWBNH™ OANA 10 Air temperature sensor 17 Pressure regulator 72 Relays 73 Cold start injector 14 Warm-up regulator 75 Vacuum/pressure switch 16 Fuel filter (at rear of vehicle) 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H2/08 /

ON INTAKE TRUNKING

H.19432

kK

CO (mixture) adjustment

Idle speed adjustment 1

Idle bypass adjuster screw

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the remote CO adjuster. Remove the

Early | |

models

Run the engine until it is at normal operating temperature. Locate the idle screw ‘1’, and adjust to achieve the specified idle speed.

tamperproof plug, and adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof plug after adjustment.

480

~~

RENIX INJECTION

Renault

Refer also to page 39

25 Turbo 85 to 89; GTA V6 Turbo 86 to 89

SPECIFICATIONS N = Non-adjustable

M

AT = Auto

= Manual

N/A = Not available/applicable

* = Throttle closed

+ = Throttle open

Static checks

Dynamic checks

Resistance characteristics

Basic checks

Injectors (ohms)

700 to 25 N

Idle speed (rpm)

Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Water temperature sensor:

eC:

(between terminals)

10 (50) 20 (68) 80 (176)

IF)

ohms

Air temperature sensor:

°C

(°F)

ohms

(between terminals)

O 20

(32) (68)

260 000 290 000

5000 2500 300

CO at 3000 rpm (%) HC at idle (ppm)

Injection duration checks Refer to Chapter 2 Injection waveform

Auto idle speed control valve

Test terminals 344 onc35 445

ohms H. 2/199 42/200

Large duration

Small duration

Engine cold:

ms

%

degrees

er 18*

Oto 10

se

Infinity

45"

26cF 1ST.

Infinity

3 & 18f

Oto 10

Test terminals

ohms

Similar to, or above, idle values

3.5

4.35

2102

ms

%

degrees

Thermotime

switch

Similar to, or above, idle values

oad

207

Te Bz.

1000 rpm

a2.

3.66

2:19

2000 rpm

2.1

7.00

4.20

20

9:99

5.99

eae)

> 9 |e)

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in?)

pipe

Pump delivery - litres/min (pints/min)....

2.5 (36) nominal 2.2 (3.9) nominal

Airflow meter/MAP sensor

Test terminals

Refer to test procedures

RENIX INJECTION

Renault 25 Turbo 85 to 89; GTA V6 Turbo 86 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve /dle speed control valve

/njectors Thermotime switch ECU Water temperature DWOANDAARWBH™

70 77 72 73 714 75 16 17 78 79 20

sensor

Air temperature sensor Pressure regulator Relays Cold start injector Warm-up regulator Vacuum/pressure switch Fuel filter (at rear of vehicle) Metering head Injector resistors Load enrichment device Additional idle control valve

Not all items fitted to all models

Renault 25 V6 shown here 421097

CO (mixture) adjustment 2

CO (mixture) adjuster screw

H.19432

- Idle speed adjustment

The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures.

CO (mixture) adjustment Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the remote CO adjuster. Remove the tamperproof plug, and adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof plug after adjustment.

482

RENIX INJECTION

Volvo

Refer also to page 39

480 ES 87 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

t = Throttle open

Static checks Resistance characteristics

Basic checks

800 + 50

Idle speed (rpm)

Injectors (ohms) Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Water temperature sensor: (between terminals)

ce

(°F)

10 (50) 20 (68) 80 (176)

ohms 5000 2500 300

CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

Oe

(°F)

O (32) 20 (68)

(between terminals)

Injection duration checks

ohms 260 000 290 000

Refer to Chapter 2 Injection waveform

Auto idle speed control valve

344

20

Cho eis)

40

445

20

ohms

H. 21199

4.21200

Small duration

Engine cold:

Test terminals

Ze

Large duration

ms

%

ms

%

0 to 10

Sree Gs

Infinity

2ocron

Infinity

3 & 18t

0 to 10

Test terminals

ohms

Test terminals

ohms

H.21203

degrees

Similar to, or above, idle values 3.5 4.64 4.16

16™

Thermotime switch

degrees

Similar to, or above, idle values 7. |

3.06

PAG wo

Fee

3.66

S20

Zn

7.00

6.30

2.0

9.99

9.00

a7 ike.

a af

Fuel system checks Fuel pressure - regulator vacuum

pipe

disconnected - bar (Ibf/in2)

2.5 (36) nominal

Pump delivery - litres/min (pints/min)....

2 (3.5) nominal

Airflow meter/MAP

sensor

Refer to test procedures

Volvo

RENIX INJECTION

480 ES 87 to 89

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve

/dle speed control valve /njectors Thermotime switch ECU (in RH footwel!) WOANDAAARWBNH™ Water temperature

sensor 70 Air temperature sensor

171 72 73 74 75 76 17 78 19 20

Pressure regulator Relays (under facia) Cold start injector Warm-up regulator Vacuum/pressure switch Fuel filter (near fuel tank) Metering head Injector resistors Load enrichment device Additional idle contro/ valve

Not all items fitted to all models

H2/096.

CO (mixture) adjustment 2

CO

(mixture) adjuster screw

H.19432

- Idle speed adjustment The engine is fitted with an automatic idle speed control, and should not require any service adjustment. If there is an idle speed problem, refer to the throttle position switch and idle speed control test procedures.

CO (mixture) adjustment Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the remote CO adjuster in the air filter. Remove the tamperproof plug and adjust the CO level to that specified. Note that the adjuster is of the electrical type, and no unnecessary force should be used. Fit a new tamperproof cap after adjustment.

Renix Injection Contents

Injection signal and duration ............cceceeeeeees ee 58. ener hrottleibutterflveSettinG) ccc. cegesees tex Stet een Rene Be. 2. Aa ct Sees PALOUILE: DOSIE OD iSWVIECDD cient cancers recat ee PasmiclesthermOStadl se scacccahrrcce eeeeneen- oe 2 citas A a es ee Automation dle: speed COmtOlleeccescceateere reese i BP RSO ASO lee redcctece tienes recente ceacr meagre acne iocas eee Water temperature SENSOF ..........ccccesccccceeeeeeeeeees

Injection signal and duration General Wherever possible, it is advantageous to check for an injection signal and the duration as a first test. In many cases, this will provide a good indication of possible faults in the electrical/electronic

operation

of the

system. Refer to Chapter 2 for instructions on how to check for injection signal and duration.

484 484 485 485 485 486 486

Ail teMmperatureeSENSO leawenaactereneeeeeti tteneccnonnen cheer ree aneaavyoeenaeee LARS CTORS Mee: ee eet SEE ss siindnnea sao nnicriee teenie ncacl ee eam Fuel system pressure and fuel pump CheCKS ...........eeeeeees Crankshaft*position/Speed SeNnSOl c...csch Meecnte..ccce esters

+ve

Terminal 7 ECU Live feed ignition on Battery

+ve

H. 21313

Relay wiring diagram

4

19

Zima

Sees

e

6

5

sous)

240

1x8

40m

Fes

200

10

27

eile

e029

ECU terminals

esSia

MOON

control relay

oeas feed to terminal 1 Fuel pump relay, terminal 19

———©)

1

5 Main

45

ot

Wie

33

34

18

35

ECU checks — Renix Injection General It is not possible, without dedicated test equipment, to carry out a direct check on the ECU. It is, however, possible to establish whether or not the ECU is functioning by carrying out the following tests. The tests are divided into two categories — one with the ECU multi-plug connected, and one with the multi-plug disconnected. It should be possible with these tests to establish that all the

connections to the system components are satisfactory, and that all the relevant signals are being passed from the sensors to the ECU. If the ECU is still not providing the correct output signals to the injectors, then the ECU should be substituted. Warning: Do not disconnect the ECU multi-plug with the ignition switched on.

ECU multi-plug terminal

Multi-plug connected (Yes/No)

Test to be carried

20 and 21 23 24

Yes Yes Yes

Check connection and signal to fuel injectors during cranking, or when running Check connection and signal to idle speed control valve terminal 3 during cranking, or when running Check connection and signal to idle speed control valve terminal 5 during cranking, or when running

1 and 2 4 5 6 4 8 14 45 16 a7? 18 19 25 29 32 33 35

No No No No No No No No No No No No No No No No No

Earth connection Battery positive Check connection Check connection Check connection Check connection Check connection Check connection Check connection Check connection Check connection Check connection Check connection Check for battery Check connection Check connection Check connection

out

to instrument panel to fuel pump relay terminal 2 to main control relay terminal 2 to throttle position switch terminal C to air temperature sensor to water temperature sensor to MAP sensor terminal C to CO adjuster terminal B, and to MAP sensor terminal A to instrument panel and voltage to main control relay terminal 5 to throttle position switch terminal A voltage with ignition on to water and air temperature sensors to MAP sensor terminal B to CO adjuster terminal A

492

Fault diagnosis — Renix Injection Test components in the order given alongside specific faults

regulator Fuel pressure controls speed idle valves Fast or filter fuel and relay Fuel pump pump,supply relays from Powercrankshaft sensor and signal Ignition relay to sensor Injectors duration and signalMAP Injection Air temperature sensor Water temperature sensor switch/sensor position Throttle Engine will not start Poor cold starting Poor hot starting EGSS'Of POWC!

..............

............:.0085

caer. yee ceencsce ane rrcnweiarrenvenire

ldie’tOO Taste ere ceeen idl6:too SIOW

acess

Unstablejidle

oo. i2iecect te tesn recone

Excessive fuel CONSUMDEION

A

1)

fep INS)

..........:.0cceeeee

Flat spot under

acceleration

No

~

eee

ee

Mirus cccececee ene

High CO at idle (adjuster INGIOCTIVE hive ree oe Low CO at idle (adjuster INGTFECTIVG) co cecseexsssecees seve eeee

KR BH O ©

aus

Renix Injection

Injection ECU

Idle speed control valve

Throttle switch

Water

Air

temperature

temperature

sensor

sensor

CO adjuster

©

Terminal 5 Fuel pump relay

©

Earth connection

Manifold pressure sensor H.213]4

Renix Injection wiring diagram

Injection ECU

O Terminal 5 Fuel pump

Cylinder 1

Cylinder 2

Cylinder 4

Cylinder 3

Cylinder 5

Injectors

Renix Injection wiring diagram

Cylinder 6

H.21315

relay

494

Rover

ROVER

820e & Se

SPI (SINGLE

POINT INJECTION)

86 to 89

Refer also to page 39

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

Static checks

Basic checks

+ = Throttle open

©

Resistance characteristics

Idle speed (rpm)

750 + 50NM

Injectors (ohms)

700 + 50 N AT

Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Fore).

Water temperature sensor:

(between terminals)

CO at 3000 rpm (%)

HC at idle (ppm)

Air temperature sensor: (between terminals)

Injection duration checks Refer to Chapter 2

Injection waveform

eareor Small duration

Engine cold:

Throttle position switch/sensor

H21/198 Large duration

ms

%

Test terminals

ohms

S5it 31

15

39

29

tS

35 4 28

15

Shape 7A)

15

[Test terminals

ohms

Refer to test procedures

degrees

Similar to, or above, idle values 3.6

5.83

5.25

ms

%

degrees

Thermotime

switch

Test terminals

Similar to, or above, idle values

PLS

2.24

1.9

SS

219

1.9

6.20

5.54

1.9

9.45

4.50

> 1%

> 15

Snap open throttle i ; ; Dwell readings are invalid on dwell meter

Fuel system checks Fuel pressure - regulator vacuum

disconnected - bar (Ibf/in2)

pipe

Pump delivery - litres/min (pints/min)....

1 (14.5) nominal 1.4 (2.5) nominal

Airflow meter/MAP sensor

Test terminals

ohms

Refer to test procedures

ROVER

Rover

SPI (SINGLE

POINT INJECTION)

820e & Se 86 to 8&9

1231-46

5 46

10am? Airflow sensor MAP sensor Throttle position switch/sensor

(also on throttle peda!) Auxiliary air valve /dle speed control valve [Injectors Thermotime switch ECU Water temperature sensor ONM™s OANDANA 70 Air temperature sensor 77 Pressure regulator 72 Relays 13 Cold start injector 74. Warm-up regulator 15 Vacuum/pressure switch 76 Fuel filter 17 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

Idle speed adjustment 1

Idle bypass adjuster screw

H.19294

Idle speed adjustment The engine is fitted with an automatic idle speed control, eliminating the need to adjust the idle as a service procedure. A basic setting is achieved by adjusting the throttle linkage, but refer to the idle speed control valve test procedure. “aie CO (mixture) adjustment The CO setting is non-adjustable, and is carried out by the ECU. Correct CO setting is usually carried out using a manufacturer's test box, but an alternative method is available.

Ensure the engine is at normal operating temperature by checking that the cooling fan has operated. Allow the engine to idle, and when the cooling fan has stopped, switch the engine off. With the ignition in the ‘on’ position, depress the throttle five times to at least a quarter of its travel and allow to return. Note that, the coolant temperature warning light will flash. When the light has stopped flashing, start the engine without touching the throttle, and allow the engine to idle until the coolant light again starts to flash. This may take more than two minutes. The CO reading can now be checked.

Rover SPI (single point injection) Contents

Injection signal and duration...

eeee ees ay Been ee sea Bas eee ee. see eee te 2 See Se © anes Water temperature SENSOF .........ccccccceececeeveseeeeeeeees ee @ Beene AiG TEMPCrAtUTESSENSOMIS ccc ctsapucnccanmpesugsroossanenens Fiteeeeeneeeeceeeeeees SMFORIEES WITCH ich.ceo.

H.2/209

Connecting a pressure gauge If the fuel pressure is higher than specified, it indicates a faulty pressure regulator, but it is possible for a blockage on the return line from the regulator to cause a high system pressure. Attach an independent pipe to the pressure regulator on the return pipe connection, run the engine, and allow the fuel to drain into a suitable container. If the fuel pressure is now at the specified level, check the vehicle return line for a blockage. If the pressure is still high, renew the regulator. If the fuel pressure is lower than specified, it is possible that the regulator is faulty, but the most likely cause is a faulty fuel pump, or a severe blockage in the fuel filter or supply line. Where possible, with the engine running or cranking, briefly clamp the fuel return line

from the regulator. If the pressure now rises substantially, it indicates a regulator fault. If the pressure remains low, carry out fuel pump checks, and also look for a fuel leak between the pump and the regulator.

Fuel pump and filter checks The fuel pump is able to provide the system with a greater quantity of fuel than is required to run the engine. The excess fuel is passed back to the tank via the fuel pressure regulator. The fuel passes from the pump through a main filter before reaching the fuel rail and injectors. The electrical supply for the pump originates at the relay, and it will only switch on the pump under certain conditions. Crank the engine, and listen for pump operation. If the pump is not running, check

513 Subaru

for supply voltage to one of the connections at the pump by repeating the cranking test. If the supply voltage is not available, check the wiring through to the relay (refer to the wiring diagram), and carry out relay checks if necessary. Check for a good earth on the remaining connection at the pump, and rectify if necessary. If the electrical connections and supply voltage are good, but the pump will not run, it should be renewed. When carrying out system _ pressure checks, if the pressure is low, or if it Is suspected that the pump is failing when the fuel demand is high, it will be necessary to carry out a flow rate and maximum-pressure check. lf a pressure gauge and tap can be connected to the system (refer to the first fuel system pressure check), turn the tap to the ‘off’ position, and crank the engine until a maximum pressure reading is reached. The pressure should reach approximately 5 bar (75 Ibf/in?) or more. If the pressure is too low, it indicates a pump fault. It is unlikely that a filter blockage will prevent the pressure from reaching the required level, unless the blockage is very severe. If the maximum pressure is acceptable, it is still advisable to carry out a flow rate check. Disconnect the fuel supply line from the fuel rail, and allow the fuel to drain into a suitable container. The test should ideally be

EPI

Relay checks General description Two relays are used, to provide a switched supply voltage to the injection system and

fuel pump. The relays require certain items of electrical information before they will switch on the system components.

Static checks Note: Refer to the wiring diagram carrying out the following checks.

relay

If, during any system component checks, it is found that there is no supply voltage available from the control relay, check for continuity from the component to the control relay. Rectify if necessary. If there is no voltage available at the fuel pump, check for continuity to the fuel pump relay, and rectify the wiring if necessary. In either case, remove the relay from the holder, and check for a live feed with the ignition on, or a permanent live feed on the control relay. Bridge the live terminal and the system the to connected terminal component. If the component now functions, suspect the relay, but refer to the wiring diagram and carry out wiring checks.

AH.2/204

Pressure regulator carried out for a period of at least thirty seconds. It will therefore be advisable to bypass the fuel pump relay to allow the pump to run without cranking the engine (refer to ‘fuel pump relay — bypassing’). Run the pump, and note the fuel quantity delivered, comparing with the specified value. A low output would indicate a probable pump fault, but a check should be made for blockages in the lines and the filter, as detailed in the following paragraph. Disconnect the fuel supply line from the filter, and repeat the fuel flow rate test by running the fuel directly from the pump to the container. If the flow rate is now close to that specified, renew the filter.

fe Main control

Note: When bridging the two relay terminals, fit a 20 amp fuse in the bridging wire, short-circuit or a possible to prevent damage.

Fuel pump relay

Live feed to fuel pump, auxiliary air valve Terminal

6 ECU

Live feed from ignition switch (fused 15 amp) Battery +ve (fusible link) O

Live feed to terminal

O

Earth connection

27/35

ECU

Live feed from ignition switch via diode and 15 amp fuse O Battery +ve (fusible link)

H. 2/417

Relay wiring diagram

when

ECU

checks — Subaru

EPI

General It is not possible, without dedicated test equipment, to carry out a direct check on the ECU. It is, however, possible to establish whether or not the ECU is functioning by carrying out the following tests. - The tests are divided into two categories — one with the ECU multi-plug connected, and one with the multi-plug disconnected. It should be possible with these tests to establish that all the

connections to the system components are satisfactory, and that all the relevant signals are being passed from the sensors to the ECU. If the ECU is still not providing the correct output signals to the injectors, then the ECU should be substituted. Warning: Do not disconnect the ECU multi-plug with the ignition switched on.

ECU multi-plug terminal

Multi-plug connected (Yes/No)

Test to be carried out

19 24 27 and 35 37 and 43

Yes Yes Yes Yes

ignition on and voltage and for live and primary

49 50 51 a2

Yes Yes Yes Yes

Check for live feed Check connection Check connection, Check connection running Check connection Check connection Check connection Check connection

is 6 2 10 25 26 28 32 38 39 56, 62

No No No No No No No No No No No No

Check Check Check Earth Check Check Earth Check Check Check Earth Check

to airflow meter terminal 3 to fuel pump relay to water temperature sensor

and 20

and 30 and 33

57, 60, 61

connection connection connection connection connection connection connection connection connection connection connection connection,

and and and and

signal signal signal signal

(via 15A fuse) to starter circuit (live feed during cranking, or when running) feed, from main relay during cranking, or when running ignition signal from ignition coil terminal 1 during cranking, or when

to to to to

no no no no

1 2 3 4

cylinder cylinder cylinder cylinder

fuel fuel fuel fuel

injector injector injector injector

during during during during

cranking, cranking, cranking, cranking,

or or or or

when when when when

running running running running

to throttle position switch to airflow meter terminal 6 to check connector to airflow meter terminal 1 to main relay and for live feed, from fuel injector resistors and main relay, terminal 2

515

Fault diagnosis — Subaru Test components

EPI

in the order given alongside specific faults

re)

5

es

9 ©es

one a

= Oo

me

= ®

ue)

”

o

9

64

Pe oc

ao.)

(CD

=

E

®

ae ce oO

=fe)

®=

ba

$_took (Cmte o

toy

oes

®

oe

=

10

D

o

c

s

ee

3 2)

“f

7) re

=

2.

©

©

o

oe ¥

to

eSok

8re 8

Z

4

3

5

&

pce

=

6S

=

s:

=

eee

See

23.et i3-3-—e— he, o

=

een ae

3

oD ®

7

6

Vf

...........:eeeee

7

5

Z

.........::.:c.eeees

i!

5

ve

.......c:eceeeeeeeeeenees

ij

2

6

6:

5

4

Sits chee nde. cierenits

7

a

Oe

Ss

5

4

Poor cold starting Poor hot starting

phi ees} «0.036442.

Unstable idle

.......c.-esccenteensenses

2

4

2

7

a

2

7

7

4

‘S;

High CO at idle (adjuster INGFFECTIVE) ...--cnecennersrensorennne

7

4

4

7

5

ye.

tensa mde eye ) u..0ch-ckd

3 3

1

..........ccseeneenees

Low CO at idle (adjuster

4

8;

deems ci cesestacden-da-tpes

Idle too SIOW

INGEFOCTIVE)

= &

>: | 2-50,

Gr

|

>

& oO

..............

Engine will not start

Excessive fuel CONSUMPTION

te

”

> o

> o

©:

+

se

FIG LOO TASU.

1°) a)

oD

‘=

§ ©

1OP

ts

=

=KY

Op

Co

BCCOIGIALION:

9 ao) oh

Oo Sexe

ot iSvante

Flat spot under

—

=

Cc

Loss Of POWEY

~ =

oO

e742c

iorn

ry

ieew

=

(eo)

3

5

4

7

6

4

5

3

©

6

nat

Subaru

EPI

Injection ECU

O

Auxiliary air valve

Water temperature

Throttle switch

Airflow meter

sensor

Subaru

Earth connection

H

2/418

EPI wiring diagram

Injection

ECU

O

Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4

Fuel injector resistors

Injectors

H. 2/419

Subaru 2.34

5 6 7 8B 9

=[=T=T={[=1=T=T=

EPI wiring diagram

10|21 2223 24 25 26 27 28|37 3839 4 41 42[—[= il

=[=l=[= [== I= [= 11

12 13 14 15

16 17 18

19 20

ECU

terminals

(Coie

e

Main relay

‘ ’

,

4

-

ie

518

Suzuki

SUZUKI

EPI

Refer also to page 39

Swift GTi 86 to 89

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

800 + 50

Injectors (ohms)

Cold start injector (ohms) Auxiliary air valve (ohms) CO at idle (%)

;

Water temperature sensor:

Refer to test procedures °C

(°F)

10 (50) 20 (68) 80 (176)

ohms

5000 2500 320

CO at 3000 rpm (%) HE at idle (ppm)

Air temperature sensor:

Injection duration checks

Airflow meter)

SGant.b)

(Combined with Refer to Chapter 2

Injection waveform

bane

_‘[Test terminals

Throttle position switch/sensor

La

|Test terminals

switch

Test terminals

H. 2/199

Small duration

Engine cold:

Auto idle speed control valve

-

Large duration

ms

%

ohms

010 10 os Infinity

degrees

Similar to, or above, idle values Be

4.96

4.48

ms

%

degrees

Thermotime

Similar to, or above, idle values

2.4

32

2.88

255

3.83

3.44

2.2

Troe

6.59

el

10.50

9.45

> 20

Polis)

Fuel system checks Fuel pressure - regulator vacuum

pipe

disconnected - bar (Ibf/in2)

2.5 to 2.7 (36 to 39)

Pump delivery - litres/min (pints/min)....

1.4 to 1.8 (2.5 to 3.2)

Airflow meter/MAP sensor

Test terminals

ohms

Refer to test procedures

SUZUKI

Suzuki

EPI

Swift GTi 86 to 89

Airflow sensor MAP sensor Throttle position switch/sensor: Auxiliary air valve /dle speed control valve Injectors Thermotime switch ECU (under LH facia) Water temperature sensor AAWNH™ MOANA 10 Air temperature sensor 77 Pressure regulator 12 Relays 13 Cold start injector 14. Warm-up regulator 15 Vacuum/pressure switch 16 Fuel filter 17 Metering head 78 Injector resistors 19 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

#f2//07

> (2)

H.19686

CO (mixture) adjustment

Idle speed adjustment

1

Idle bypass adjuster screw

run it for Ensure the engine is at normal operating temperature, and the idle ng approximately twenty seconds at 2000 rpm before adjusti and body, throttle the on ‘1’ speed. Locate the idle bypass adjuster to adjuster the in Screw fitted). (where remove the tamperproof plug speed. the increase to adjuster the unscrew or speed, idle decrease the Fit a new tamperproof plug where appropriate.

H.19687

2

CO (mixture) adjuster screw

run it at Ensure the engine is at normal operating temperature, and engine the With . approximately 2000 rpm for around twenty seconds ECU. the on ‘2’ adjuster CO at the correct idle speed, locate the that to level CO the adjust and plug, roof Remove the tamperp and no type, al electric the of is adjuster the that Note d. specifie after unnecessary force should be used. Fit a new tamperproof plug adjustment.

Suzuki

EPI

Contents

Injection signal and duration ............cceceeees pean 1G, Scenes Fhrottle btitterfly settingpsyitise anata des.s32..:. Re. 8 Ree ees MMPOtLles POSITIONERS IS Olan tenrcee tenes cetete cone: Seo: RRR Ee AAUXUlanVacdlIaiVia VC retin cane eres oe aS, em XI GTLONVESCISOlnsceessent eet tanec cea tages etc

Injection signal and duration General Wherever possible, it is advantageous to check for an injection signal and the duration as a first test. In many cases, this will provide a good indication of possible faults in the electrical/electronic operation of the system. Refer to Chapter 2 for instructions on how to check for injection signal and duration.

H. 2/200 Injection waveform

520 520 520 521

Water temperature S@NSOM cspisec.tb-

listen for pump

operation. If the pump is not running, check for supply voltage to one of the connections at the pump by repeating the cranking test. If the supply voltage is not available, check the

H.2/209

Connnecting

a pressure gauge

524

Suzuki

If, during any system

Relay checks General description Two relays are used, to provide a switched supply voltage to the injection system and

fuel pump. The relays require certain items of electrical information before they will switch

on the system components.

Static checks Note: Refer to the wiring diagram carrying out the following checks.

Fuel

pump relay

EPI

component

checks,

it is found that there is no supply voltage available from the control relay, check for continuity from the component to the control relay. Rectify if necessary. If there is no voltage available at the fuel pump, check for continuity to the fuel pump relay, and rectify the wiring if necessary. In either case, remove the relay from the holder, and check for a live feed with the

ignition on, or a permanent live feed on the control relay. Bridge the live terminal and the

terminal

connected

to

the

system

component. If the component now functions, suspect the relay, but refer to the wiring diagram and carry out wiring checks. Note: When bridging the two relay terminals, fit a 20 amp fuse in the bridging wire, to prevent a _ possible short-circuit or damage.

when

Main

control

relay

(C) Live feed to Terminals

A & C ECU

(.) Live feed to Terminal 2Q/3B ECU, Terminal

86 Fuel pump,

idle-up valve

©) Terminal 20 ECU () Live feed with ignition on () Fused

link via

battery

+ve

() Fused link via battery +ve () Live feed to fuel pump (.) Terminal

2H ECU

© Terminal 87 Main control relay C) Fused

link via battery +ve

AH. 2/400

Relay wiring diagram

a

ECU

checks — Suzuki

EPI

General It is not possible, without dedicated test equipment, to carry out a direct check on the ECU. It is, however, possible to establish whether or not the ECU is functioning by carrying out the following tests.

The tests are divided

into two categories — one with the ECU

multi-plug connected, and one with the multi-plug disconnected. It should be possible with these tests to establish that all the

~

connections to the system components are satisfactory, and that all the relevant signals are being passed from the sensors to the ECU. If the ECU is still not providing the correct output signals to the injectors, then the ECU should be substituted. Warning: Do not disconnect the ECU multi-plug with the ignition switched on.

ECU multi-plug terminal

Multi-plug connected (Yes/No)

Test to be carried out

5 ao. # mau, ZN, 2P and 2R F W 20 and 3B 3A m7 oe, 3G and 3l BL, SF, 3H and 3J

Yes

Check for battery feed from main control relay terminal 87a during cranking, or when running

Yes Yes Yes Yes Yes

Earth Check Check Check Check

Yes

Check for battery feed to fuel injectors 1, 2, 3 and 4 respectively during cranking, or when running

Yes

Check for injection signal to fuel injectors 1, 2, 3 and 4 respectively during cranking, or when running

No No No No No No No No No No No No No No No

Check Check Check Check Check Check Check Check Check Check Check Check Check Check Check

eT

E, |, and K G H J M O Q R T 4s 2E 2H 2 2J 20

connection for battery for primary for battery for battery

connection connection connection connection connection connection connection connection connection connection connection connection connection connection connection

feed (via fuse) from battery positive during cranking, or when running ignition signal during cranking, or when running feed from main control relay terminal 87 during cranking, or when running feed during cranking, or when running

to to to to to to to to to to to to to to to

airflow meter throttle position sensor terminal throttle position sensor terminal diode pack for heater water temperature sensor oxygen sensor (if fitted) throttle position sensor terminal throttle position sensor terminal diagnostic connector ‘check engine’ lamp idle-up valve fuel pump relay terminal 85 ignition advance valve EGR valve (if fitted) main control relay terminal 85

A C

B D

526

Fault diagnosis — Suzuki

EPI

Test components in the order given alongside specific faults

55

0

= (e)

th

Fp

res s

One Cee

Ole

ee Obes

5

eo)

s

=

Be

aS Foe

c

pee

uty

ECE

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8&

® as

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rer

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2.

es

oie ee wtse rater

c

oe 0

=

heede oe >

>

£

5

&

rA

re

tzineaecs

®

Svfini EL993 SrBe ovataeae euopeas 8 ong

Ignition signal relay to Fuel regulator pressure Injectors

..............

7

6

Vi

1e%)

..................

7

5

2

.................0

7

is)

2

if

2

Omer

5

KR OO ® ©

7

2

6

ie

A

Engine will not start.

fii. cccnucscten cee

Flat spot under acceleration .........cccccecseceeeees tee

ee

ee

Idle too SIOW

......ccccecececeseeeeeees

Unstable idle

..............ccccceseeees

Excessive fuel CONSUMPTION,

1S}

ae

rp

out

fale COO fast)...

&

2

=

LOSS OT POWGP

3

=

.

eT © ®

Poor hot starting

o

t=

a) ne)

Poor cold starting

oO

~ —

2250-0-. eee

High CO at idle (adjuster inetfective); ..2..255 ee

3)

Oe

A

3 8)

1

4

Z

7

3

w

wh

7

2

3

7

4

2

fr

eaneGOe

nen

5

Low CO at idle (adjuster

ineffective) 0:42.

4

es

A

Suzuki

nes

EPI

. Tbaleboe T lsh ECU

connection ©) Terminal 87 Main control relay

Da a’

oe

| ee

| enka

2401 AH

Di

=

connection

6

AR

Wie

Water

sensor

valve

valve

temperature sensor

Suzuki

Cylinder

Airflow meter

EPI wiring diagram

2

Cylinder

1

Throttle sensor

Cylinder 4

3

Cylinder

AH 2/402 Fuel

Suzuki

BSD

er

he

bene

See

RT

injectors

EPI wiring diagram

NO

Pen

ROB

=[-J-[-I-I- IgISI= T= I=

DR

As.

etter -j|-[-)

ECU

terminals

.

528

Toyota

TOYOTA

EFI

Refer also to page 39

Camry 2.0 GLi 84 to 87

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)...........

750° + 50

Injectors’ (OnMS) maps Jaan stan. Cold start injector (ohms) .......

1.5) tors 2 to 4

Auxiliary air valve (ohms)........ COMBRIGIEH IO) 10 ova sa eee

1.0 + 0.5

CO at 3000 rpm (%).......

< 0.5

ee

a

ADDU en

oe cacy

Water temperature sensor:

°C

(°F)

ohms

80 (176) Air temperature sensor:

°C

ohms

5500

OR(32)

(THA & E2 in

Injection duration checks

(°F)

Airflow meter)

20 (68)

2500

Refer to Chapter 2 Injection waveform

4, 2/200

H. 2/199

Small duration

ms tore:

re hatoderiaat =.soutien

ee ee

die. ...2. oe eee,

carseat ae

peered ie ge

Throttle position switch/sensor

|Test terminals

ohms

(Diet Vise

0 to 10

TL & PSW*

Infinity

ee a

eee

%

IDL

degrees

4.99

4.49

Tet

Infinity

TL & PSWt

0 to 10

Test terminals

ohms

STJ & Switch body

ms

% degrees se C Similar to, or above, idle values

20

ees)

El a ECT

0 to 10

E2 & VB

260 to 520

VS & VC

260 to 1040

meee

Fuel system checks Fuel pressure - regulator vacuum

a

Similar to, or above, idle values

RE

Engine warm: : Cranking we a 2 eae

casted

Test terminals

Large duration

Engine cold: Cranking snc

Auto idle speed control valve

CJ 42/320

pipe

disconnected - bar (Ibf/in2) ..............

2.3 to 2.7 (33 to 39)

Pump delivery - litres/min (pints/min)....

1.5 to 2 (2.6 to 3.5)

Toyota

TOYOTA

EFI

Camry 2.0 GLi 84 to 87

Airflow sensor MAP sensor Throttle position switch/sensor Auxiliary air valve [dle speed control valve Injectors Thermotime switch ECU (under facia) Water temperature sensor WOANDAAARWBH™ 10 Air temperature sensor 771 Pressure regulator 72 Relays 13 Cold start injector 714 Warm-up regulator 75 Vacuum/pressure switch 76 Fuel filter 17 Metering head 78 Injector resistors 79 Load enrichment device 20 Additional idle control valve Not all items fitted to all models

H.2/049

H.20379

CO (mixture) adjustment

Idle speed adjustment 7

Idle bypass adjuster screw

Ensure the engine is at normal operating temperature, and run it for - approximately twenty seconds at 2000 rpm before adjusting the idle speed. Locate the idle bypass adjuster ‘1° on the throttle body, and remove the tamperproof plug (where fitted). Screw in the adjuster to decrease the idle speed, or unscrew the adjuster to increase the speed. Fit a new tamperproof plug where appropriate.

2

CO (mixture) adjuster screw

Ensure the engine is at normal operating temperature, and run it at approximately 2000 rpm for around twenty seconds. With the engine at the correct idle speed, locate the CO adjuster ‘2’ on the airflow meter, and remove the tamperproof plug (where fitted). Using either an Allen key or screwdriver, screw in the adjuster to increase the CO, or unscrew the adjuster to reduce the CO level. Set the CO reading to that specified, and fit a new tamperproof plug.

530

Toyota Crown

TOYOTA

EFI

Refer also to page 39

Super 80 to 84; Celica Supra 82 to 86

SPECIFICATIONS N = Non-adjustable

M = Manual

AT = Auto

N/A

= Not available/applicable

* = Throttle closed

Dynamic checks

+ = Throttle open

Static checks

Basic checks

Resistance characteristics

Idle speed (rpm)

SOU

50

Injectors (ohms)

800 (Crown)

Cold start injector (ohms) Auxiliary air valve (ohms)

CO at idle (%)

Water temperature sensor: 2.0 + 0.5 (Crown)

80 (176) CO at 3000 rpm (%) HC at idle (ppm)

Air temperature sensor:

(THA & E2 in Airfl

(°F)

one

ow meter)

Injection duration checks

°C

20

(68)

Refer to Chapter 2

Injection waveform

4. 2/200

_—‘[Test terminals

Throttle position switch/sensor

|Test terminals

ohms

IDL & TL*

0 to 10

TL & PSV

Infinity

IDE-E, TET

Infinity

TL & PSWt

0 to 10

Test terminals

ohms

H. 2/199

Small duration

Engine cold:

Auto idle speed control valve

Large duration

ms

%

degrees

Similar to, or above, idle values 4 5.33 3.19 ms

%

STJ & Switch body

degrees

Similar to, or above, idle values

Fuel pressure - regulator vacuum

Oto 10

Zo

3.093

1:99

2.4

4.00

2.40

253

7.66

4.59

Test terminals

ohms

22.

11.00

6.66

Ea Gor.

Infinity

> 20

> 12

E1 & FCt

0 to 10

E2 & VB

260 to 520

VS & VC

260 to 1040

Fuel system checks disconnected - bar (Ibf/in2)

Fuel system pressure checks The system should provide fuel to the fuel rail and injectors, at a pressure which is constant in relation to the manifold pressure. The system consists of a pump, main filter, fuel rail (to distribute the fuel to the

H.2/209 Connecting

a pressure gauge

Toyota

Note the fuel pressure. Disconnect the vacuum pipe connecting the fuel pressure regulator to the inlet manifold, and plug the hole to the manifold. The fuel pressure should increase to the specified value. (During cranking, the engine only produces a low vacuum level, therefore the fuel pressure will be very close to the specified level even if the vacuum pipe remains connected.) Also note that on an engine which is running, the same test can be carried out using a CO reading, which should increase in conjunction with the fuel pressure increases.

return line for a blockage. If the pressure is still high, renew the regulator. If the fuel pressure is lower than specified, it is possible that the regulator is faulty, but the most likely cause is a faulty fuel pump, or a severe blockage in the fuel filter or supply line. Where possible, with the engine running or cranking, briefly clamp the fuel return line from the regulator. If the pressure now rises substantially, it indicates a regulator fault. If the pressure remains low, carry out fuel pump checks, and also look for a fuel leak between the pump and the regulator.

Note: A/though the system pressure may be correct when the engine is running under workshop test conditions, it does not prove that the pressure and fuel flow are acceptable at high engine speeds and loads. Unless the pressure can be checked with the vehicle on a rolling road, it will be necessary to carry out fuel pump checks, to establish whether the pump can supply safficient fuel at the required pressure when the fuel demand ts high.

The fuel pump is able to provide the system with a greater quantity of fuel than is required to run the engine. The excess fuel is passed back to the tank via the fuel pressure regulator. The fuel passes from the pump through a main filter before reaching the fuel rail and injectors. The electrical supply for the pump originates at the pump relay, and when the ignition switch is in the cranking position, the relay will provide an electrical supply to the pump. When the engine starts, the airflow meter flap moves due to airflow through to the engine. A set of contacts is closed (by the flap movement), completing a second relay circuit which keeps the relay contacts closed, thus maintaining pump operation. Crank the engine, and listen for pump operation, or alternatively push open the airflow meter flap with the ignition switched on. If the pump is not running, check for battery voltage to one of the connections at the pump by repeating the test. If the supply voltage is not available, check the wiring through to the relay terminal FP (refer to the wiring diagram), and carry out pump _ relay checks if necessary. Check for a good earth on the remaining connection at the pump, and rectify if necessary. If the electrical connections and supply voltage are satisfactory but the pump will not run, it should be renewed. When carrying out system pressure checks, if the pressure is low, or if it is suspected that the pump is failing when the fuel demand is high, it will be necessary to carry out a flow rate and maximum pressure check. A pressure gauge and tap should be connected to the fuel supply line, with either a tap after the gauge, or the outlet from the gauge blanked off (for this test it is not necessary for the fuel to flow past the gauge into the fuel system). Crank the engine, or bypass the pump relay, until a maximum pressure reading is reached. The pressure

Gin|

942.000)

AH.2/204

Pressure regulator

With the engine running, if the fuel pressure is already at the specified level prior to disconnecting the regulator vacuum pipe, the pressure regulator is likely to be faulty, but ensure that manifold vacuum is available from the vacuum pipe, and that there are no leaks. If the fuel pressure is higher than specified, it indicates a faulty pressure regulator, but it is possible for a blockage on the return line from the regulator to cause a high system pressure. _ Attach an independent pipe to the pressure regulator on the return pipe connection, run the engine, and allow the fuel to drain into a suitable container. If the fuel pressure is at the specified level, check the vehicle

Fuel pump

537

EFI

and filter checks

should

reach

approximately

6

bar

(85

Ibf/in?) or more. If the pressure is too low, it indicates a pump fault. It is unlikely that a filter blockage will prevent the pressure from

reaching the required level, unless the blockage is very severe. If the maximum pressure is acceptable, it is still advisable to carry out a flow rate check. Disconnect the fuel supply line from the fuel rail, and allow the fuel to drain into a suitable container. The test should ideally be carried out for a period of at least thirty seconds, It will therefore be advisable to bypass the fuel pump relay to allow the pump to run without cranking the engine (refer to ‘fuel pump relay — bypassing’). Run the pump, and note the fuel quantity delivered, comparing with the specified value. A low output would indicate a probable pump fault, but a check should be

made for blockages in the lines and the filter, as detailed in the following paragraph. Disconnect the fuel supply line from the filter, and repeat the fuel flow rate test by running the fuel directly from the pump to the container. If the flow rate is now close to that specified, the filter should be renewed. If the flow rate is still too low, renew the pump.

Cold start injector and thermotime switch General description The cold start injector is used during cranking only, to aid the initial starting phase. During cranking, the cold start injector is switched on by a thermotime switch (located in the cooling system). The thermotime switch will allow the injector to operate when the water temperature is below a pre-determined value. During cranking, voltage is also supplied to a heating element in the switch, causing the switch to break the cold start injector earth circuit. The thermotime switch can switch off the injector almost immediately, or after as long as eight to twelve seconds, depending on the initial water temperature. Note: 7he pre-determined temperature, and the maximum time taken for the heater to open the contacts, are usually stamped on the thermotime switch body.

Static checks Prevent the engine starting by using the ‘engine-kill’ facility on the test equipment, or by disabling the fuel pump (refer to the fuel system pressure and pump checks). Ensure that the water temperature is below the predetermined level — if necessary, remove the thermotime switch and place in cold water.

538

Toyota

EFI

cranked for a period equivalent to the time value stamped on the switch body. Im-

mediately disconnect the switch plug, and check the resistance between the switch terminal ‘STJ’ and earth. There should now be an open-circuit reading. If the switch remains closed (zero ohms), renew It. Remove the injector from the intake manifold, and connect all the fuel and electrical connections. Crank the engine (ensure that the temperature is below the predetermined level), and check for a wide conical spray pattern. A poor pattern would indicate the need for injector cleaning or renewal. No injection at all would indicate a faulty injector, but first check for acceptable fuel pressure.

H.212/2

Cold start injector

that the temperature

Pump relay If it is suspected that the pump relay is not operating, remove the relay from its holder, and bridge the relay holder terminals corresponding to B and FP. If there is now a live feed to the components, it is likely that the relay is at fault, but carry out the following checks. Check for a live feed to relay holder terminal STA during cranking. Check that the airflow meter switch is opening (opencircuit on airflow meter terminals E1 and FC) when the flap is pushed open, and also check that there is a good connection from relay terminal FC to airflow meter terminal FC. Check for an earth connection at relay holder terminal E1. If the connections are all satisfactory, renew the relay.

Control! relay

Disconnect the plug from the cold start injector, and crank the engine. Check for battery voltage to one of the two terminals on the plug (terminal ‘STA’). If there is no voltage, check through the wiring back to the ignition switch (start position). . Disconnect the thermotime switch plug, and check for continuity between the live terminal on the injector plug (‘STA’) and one of the two terminals on the thermotime switch plug (‘STA’). Also check for continuity on the remaining injector plug terminal (‘STJ’) to the remaining thermotime switch terminal (‘STJ’). Rectify as necessary. With the plug still disconnected, check the specified resistance across the two injector terminals. A short- or open-circuit indicates a faulty injector. Examine the plastic top of the thermotime switch with the plug disconnected. There should be letters corresponding to the two terminals, typically ‘STA’ and ‘STJ’. Check the resistance between ‘STJ’ and earth. The reading should be zero ohms if the temperature is below the predetermined value. If the temperature is above the predetermined value, there should be an open-circuit or infinity reading. If readings are incorrect, renew the thermotime switch. Test the heating element by checking for a resistance between STA and earth. The exact reading will depend on the type of switch fitted, but if a zero ohm or opencircuit reading is obtained, renew the switch. Carry out the remaining checks detailed below. Ensure

pump relay terminal B with the ignition on. If the control relay is supplying the voltage, continue with the pump relay checks, but if there is no voltage, check the control relay.

is below

the

predetermined level, reconnect the plug and crank the engine. The engine should be

If it is suspected that the control relay is not functioning, carry out the following checks. Check for a live feed with the ignition on to relay holder terminal 1. The feed originates from the ignition switch, via a 7.5 amp fuse. Check for a good earth connection to relay holder terminal 2. Check that a permanent live feed is available to the holder terminal 3. The supply is direct from the battery, vioia a 15 amp fuse. If all connections are satisfactory, renew the relay. If there are any doubts, with the relay removed from the holder, connect relay terminal 1 to battery positive, and terminal 2 to earth. The relay contacts should now close, and this can be checked by testing for continuity between terminals 3 and 4. If the contacts do not close, renew the relay.

ie Thermotime switch Plug terminal is brown

Relay checks General description Two relays are used, to provide a switched supply voltage to the injection system and fuel pump. The relays require certain items of electrical information before they will switch on the system components. Note that the control relay supplies a live feed to the ECU and the pump relay. The pump relay, when switched on, supplies a live feed to pump, auxiliary air valve and idle speed control valve, where fitted. The pump relay is also connected to a safety switch on the airflow meter (when fitted). This will prevent the relay operating if there is no air being drawn through the ariflow meter. Note: Refer to the wiring diagram carrying out the following checks.

when

If, during any system checks, it is found that there is no supply voltage available from the pump relay terminal FP, check for voltage from control relay terminal 4 to

Inertia switch

Me

gWS: Vv

WS th

4 ,

‘s SS IQ RN

H.2/216 Typical inertia switch

Toyota

EFI

Static checks

An inertia switch is fitted on some vehicles, which will cut off the electrical supply to the fuel pump, and possibly other components, in the event of an accident.

If it is apparent that there is no live feed to the pump or other components, locate the inertia switch, and check for continuity between the two terminals. If the switch is Fuel pump

Main control relay

continuity),

(no

open

General description

relay

Es 3

1

2

4

O) Live feed to fuel pump,

auxiliary air valve

Q Terminal FC Airflow meter O Earth connection Live feed from starter circuit CO) Live feed from terminal 4 Main Live feed from terminal

control relay

B ECU, terminal

B Fuel

pump relay O Earth connection () Live feed from O

H2/32!

Relay wiring diagram

operate

the

reset

button. If the switch is still open, renew it.

ignition switch

Live feed from battery

+ve

(fused 7.5 amp)

(fused 15 amp)

ECU checks — Toyota EFI General It is not possible, without dedicated test equipment, to carry out a direct check on the ECU. It is, however, possible to establish whether or not the ECU is functioning by carrying out the following tests. The tests are divided into two categories — one with the ECU multi-plug connected, and one with the multi-plug disconnected. It should be possible with these tests to establish that all the

connections to the system components are satisfactory, and that all the relevant signals are being passed from the sensors to the ECU. If the ECU is still not providing the correct output signals to the injectors, then the ECU should be substituted. Warning: Do not disconnect the ECU multi-plug with the ignition switched on.

ECU multi-plug

Multi-plug connected

terminal

(Yes/No)

STA THA VS

Yes Yes Yes

IG 10 and 20

Yes Yes

NSW BATT +B and

Yes Yes Yes

Check Check Check Check Check Check Check Check

VB

No

Check connection

VC ETreZ, EOQImEOZ,

No

Check connection to airflow meter terminal VC

E21

No

Earth connection

IDL and PSW THW

No No

Check connection to throttle position switch Check connection and voltage to water temperature sensor

T and VF

No

Check

G

No

Check connection to engine check warning lamp

+Bl

Test to be carried out

connection connection connection connection connection connection connection connection

connection

to starter circuit, and for live feed during cranking, or when running and voltage from airflow meter terminal THA during cranking, or when running and voltage to airflow meter terminal VS during cranking, or when running and signal from ignition coil terminal 1 during cranking, or when running and signal to fuel injectors during cranking, or when running and voltage from starter circuit during cranking, or when running and voltage from battery positive during cranking, or when running (fused 15A) and voltage from main relay terminal 4 during cranking, or when running to airflow meter terminal VB

to check connector

541

Fault diagnosis — Toyota

EFI

Test components in the order given alongside specific faults

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