Volvo 240 1976-1978, 260 1976-1978 Fuel Injection System Fault tracing

Fault tracing el Fuellnjection System

240/260 1976-1978

Section Group

2 24

el Fuel Injection

System

240/260

Contents

Introduction ..

.

.....

..

......

.

....

.

.

.

.

..

.

...

...

.

.

...

....

.

.

..

Specifications / description ..........

.

.

....

..

•.• .

.

..

.

.•.• .

.

.

.

Special tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . • . . . . . . • . . . . . .

CI System. B21 F. expl o ded view . . . . . . . • . . . . . . .

CI System, B27F, exploded view ...

.. ..

• ....

...

Fault tracing guide (quick reference) ....

.

...

.• . , .

. • . • . . . .

........

. .•. , . ,

Symptoms:

Cold engine difficult to start or no start ...

.

.

.

.•. ,.

.

..

...

...

.

.

.

W<!'m engine difficult to start ......

....

..

....

..

•.

.

....

Cold & warm engine difficult to start ..... , . , ........ , . .

Erratic running engine /cold or during warmup ...

.

.

• .

.

.....

Erratic running warm engine .......................

.

..•.

..

.

..

Errati c running engine cold & warm . . . . . . . . . . . . . . . . . . . . • . . . . . .

Erratic running engine & high fuel consumption .....

.

.•. , .

.

....

Rough id l e .......................................... ,.

..

.

.

.

Low top speed (poor engine performance) ....... , . . . . . . . . . . . . .

High fuel consumption ........................

.

. , .

.

.

.

.

.

.

.

...

Fault Analysis:

Fuel pump operation simple check ..

..

..

..

..

....

.

..

. A 1-A3

Fuel pump inoperative 1976-1977 vehicles ..

..

...

.. A4 A 10

1978vehicles ..........

..

.. All A17

Fuel Supply:

Line pressure too low

Exce ssive line pressure

Bl-B3

B4

Electrical Supply:

Check fuses .......................

.

...... , .

.

.

.

.

.

... .

Check main relay 1976-1977 .

....

..

..

..... , ......... .

C1

C2

Air intake / throttle valve B2 1 F .......

• .

.

.... ,...

.

... 01-02

B27F ............

.

....

..

... 03 06

Air flow sensor B21 F ..............

.

...•.•.

.

........ E 1 E4

B27F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. E5-E8

Cold start injector / thermal time switch ............

..

... F 1 F9

Quick reference for possible problems invol ving cold start injector

Auxiliary air valve ........ .. .. .. .. .. .. .. ... G l-G4

Line and rest pressure ....

..

......

..

.

.

.

........ . . . .. H l-H 13

Controi pressure ..

.

....

.

.......

•.•. , .

.

......

.

.

.

...... 11-111

Injectors & fuel distributor .

..

.

.

.

...

.

.

.

.

.

.

.

.

..

..

.

.

..

.. Jl-Jl0

CO Emissions Check:

B21 F not equipped with Oxygen Sensor Feedback System ...

..

..

... , . • . . .. K 1 K3

B27F not equipped with Oxygen Sensor Feedback System . . . . . . . . • . . . . . . L l L 7

B21 F equipped with

Oxygen Sensor Feedback System .

..

.

.

.

..

.

.

.

.• .

..

.... M 1 M7

B27F equipped with

Oxygen Sensor Feedback System ...

• .

.

.

....

..

. ,..

.

. N l N 11

Additional information:

Eliminating Oxygen Sensor Feedback System. . • . . . . . .. 01 07

Wiring Diagrams:

240 1976 ......

.

..

..

..

..

.

....

..

...

...

.....

...........

...

.

1977 ......

..

.

.

..

...

..

.........

....

......

1978 .

..

..•.

• ....•.•.

• ....•...

.

.

.

.

• ....•.

• ......•.

.

.

.

260 1976 ......

....

..

.

..

..

.

..

...

...

..

..

...

..

.

..

....

..

...

.

1977 ...

.

. ,..

..

......

.

....

.

.

.

.

.

........

...

..

.

.

.

.

.

....

-1978........

..

.......

..

.......

..

.

.

..

.

..

....

..

....

...

12

14

15

16

17

18

19

20

21

22

23

24

26

Page

1

2

7

9

10

1 1

29

30

31

31

32

33

34

35

37

40

41

43

48

52

56

57

60

62

66

68

70

72

74

76

78

el System, Fault Tracing

Introduction -

Introduction

The fault tracing instructions in this manual are presented with the assumption that all mechanical, electrical or emission system faults which may have existed have been eliminated. The following items in the above mentioned areas should have been checked using appropriate methods specified in the associated

Service Manual.

Mechanical

Compression

- Valve clearance

- All vacuum lines and connections

Transmission kickdown cable and throttle valve adjustments

Air cleaner

- Ducts

Intake manifold (leaks)

Electrical

Spark plugs

- Spark plug leads

Distributor cap

Ignition coil

Timing (including advance mechanism)

All electrical connections

Emission Controls

- Crankcase ventilation system (PCV valve)

Exhaust gas recirculation system

- Air injection reactor system

Evaporative controi system

- Lambda-sond system (see op. O 1-<l7)

- Catalytic converter

Specifications

Refer to the "Specifications" Section O (03) in the

Service Manuals for proper clearances and other va lues regarding systems other than the Fuel Injection System .

Common symptoms

Only those symptoms which are most common and easily detected are dealt with in this manual.

Complex symptoms

In the event that several CI System components fail, or more complex symptoms occur, it may be necessary to overhaul the entire system. Perform a complete analysis before proceeding with ex-

tensive repairs.

Overhaul

Performing operations B 1 to

J

1 O will prov ide a continuous fault tracing of the fuel injection system. Refer to the "Repair and Maintenance"

Section 2 (Group 24) in the Service Manuals for complete overhaul instructions.

Additional information

The Oxygen Sensor Feedback System (Lambda

Sond System) is in a way a subsystem within the fuel system.

Information on how to isolate that system is therefore included as operations 01-<l7.

3-step information

Many of the fault-tracing procedures contain an illustration, a brief statement and a more detailed instruction. This 3-step format is designed to provide the mechanic with an overview of the particular fault-tracing operation or procedure.

This, in many cases, is sufficient to enable the experienced mechanic to proceed without additional instruction. Others may need the more detailed instruction to review or learn what is needed to accomplish the operation.

Note: If CI System parts are replaced, the id le speed and CO level must be checked and readjusted as necessary.

TP 12044/1

3000.04.7B

Printed in USA

Group 24

FuelSystem


- Specifications

/

De scription -

Specifications / Description

fuel feed pump filter

Fuel feed pump

The fuel feed pump was introduced during the

1977 model year . It can be retrofitted on earlier year cars , see Service Bulletins No. 12A and 14,

Group 24.

A number of 1976 260 Series Models were equipped with fuel feed pumps.

The fuel feed pump is located in the gas tank (integral with the fuel tank gauge sender) . Fuel is thereby supplied under low pressure to the main fuel pump thus reducing the possibility of vapor lock.

A non-return valve causes fuel to be maintained under low pressure in the hose between the two pumps with the engine not runn ing.

Current consumption: 1-2 amps. accumulator fuel pump

'25904

Fuel pump and accumulator

1976-1977 Modeis: l ocated on a braeket at tached to the outside of the fuel tank.

On 1977 Models the protector plate for the fuel pump was red esigned so that the fuel pump can be removed without loo se ning the fuel pump braeke!.

1978

Modeis: Location for fuel pump and accumulator was changed from the fuel tank to the cross member under the floor of the vehicle

(beneath the rear seat).

260

Series: fuel accumulator capacity increased from

20 cm' to

40 cm ', improving starting capabilities at all temperatures .

The fuel pump is an electric , roller type pump , capable of supplying approx .

1 .

6 liters

(1 .

7 qts) of fuel at 5 kp / cm' (=70 psi) .

Current consumption: max . 8.5 amps.

123 1 0 1

2

Group 24

Fuel System


- Specificat/ons

/

Description -

",JUU

U U U

Fuel filter

This paper element filter is located on the firewall , see illustration.

Replacement intervals: 40,000 km

30 , 000 miles

125910

\l'wmaI"",._

, w mi'"

,olov coId

1, .. \ in)ec1Of

.,ar \ ", MO ' O<

87 "'--t SB--(I

,--

--

;;~~~

----~.,~,,

~=:

oo

:"":

":~

~

,

~~~~

(Mr !k:IwHnOOr +

!

ueI<30StribIJtOfI

Relays

On 1976 Modeis, the main relay and the fuel pump relay are located to the left on the front of the firewall , behind the ignition coil.

On 1977 Modeis , the two relays are moved to the inside of the firewall.

B7.

<=

108 7 04

Con trc l pusoun r e g ul at or

O O

Cold n U t

I n jecto< t

B7

3 1 15

.Il..

31b

On 1978 Modeis , the main relay , the fuel pump relay and the switch at the air flow sensor have been replaced by one electronic type relay . It is 10ca ted in the passenger compartment, to the left up behind the firewall.

The electronic fuel pump relay is a standard cut-in type with a pulse sensor that reacts to the signa l s from the electronic m odule in the ignition system .

With the engine running (jgnition system firing ), the pulse sensor allows voltage to pass through from connection 15 and activate the relay .

123605

Group 24

Fuel system

3

el System , Fault Tracing

- Specifications

/

Oe script ion -

~G!

----=::::::\ , ~

1976 1 917 versio n l.......-

- - -

10897 8

B21F and B27F

Lin e pressure : 4.5-5.2 kp / cm 2

64-75 psi

R est pressure:

minimum:

maximum

1.7 kp / cm '

=

24 psi be low inj ector opening press ur e

Line pressure regulator

L ocation: in fuel distributor , see CI Fu el System exp loded views (B21 F) and (B27F).

Line and rest pressure adjustment

Remove or add shims in the lin e pressure regulator.

Ther e are two shi m s avai l able :

0 .1

mm

provides 0 .

06 kp / cm 2 = 0 .

8 psi pressure difference.

0 .

5

mm

provides 0 .

3 kp / cm 2 = 4 .

3 psi pres sure difference .

Use the thicker shims for adjustment where possib l e. When shims are added , the line pressure wi ll increase and the rest pressure wi ll decrease . If sh im s are removed , the lin e pressure will decrease and the rest pressure will increase .

Controi pressure regulator

Regulation in the co ntr o i pressure regulator i s provided by a bim etal spring which i s influenced by:

ambient temperature

a nd a heating coi l wrapped around the bimetal spr in g. The heating coil is ene r gized du rin g starte r motor and eng in e operation.

kp / cm '

4 .

0 , - - , _ , - - - - , _ - , _ , - - - - , _ - , _ , - - - ,

)

3.0

+---+_-+_ +_+---+_

2.0

t-

-+

-f--c:

1.0

I-~--+ -+--I--I--'-+---l---' o

1 9 20 30 40 50 60 70 80 ' C

32 50 68 86 104 122 14 0 158 176 F

1 0874 9

B21F

Controi pressure, engine at normaloperating temperature:

3 .

7

±

0 .

2 kp / cm '

50-55

psi

Contro i pressure , co ld eng in e :

see diagram at left

4

Group 24

Fuel system


Specifications I Description -

B27F

The B27 controi pressure regulator contains a tube with one of the foliowing connections:

- Federal specification vehicles to the rear of the intake manifold which pravides vacuum to the tube. This causes enrichment of the air I fuel mixture at maximum speed .

- California specification vehicles (also Lambda sond equipped) to open air .

125 91 1

kp / cm

2

B 27 F

4.0

,----,--,------r ---,--,---,---,:;~,

3 .

7

~.vl_

--j-

Vacuum hose connectcd

+~ +

Contral pressure, engine at normaloperating temperature:

Tube vented to atmospheric pressure:

3.3

±

0.15 kp / cm'

45-49

psi

Tube connected to vacuum:

3.7

±

0.2 kp/cm'

50-55 psi

Controi pressure , cold engine:

- see diagram at left.

32

70 80' C

68 86 104 122 140 158 176 F

12 0997

High altitude areas

B21F and B27F (1977 year models):

A special controi pressure regulator Volvo P

I N

1219952 is used. It incorporates an altitude compensating device and is ventilated to open air.

(Bosch P

I N 0438140021)

Group 24

Fuel system

5

el Sys t e m , F a ult T raci n g

Spec if ica t ions

/

D esc ripti o n -

Injectors

Th e i nj ec t ors co nt ai n a sp rin g -I oaded disc type va l ve.

Opening pressure :

2.6-3 .

6 kp / cm '

= 37-51 psi

No l eakage pe rm i tt ed b e l ow 2.4 kp / cm ' 34 psi.

125922

Cold start injector

Supp l ies extra f ue l to the engine when starting.

Th e so l enoid ope r a ted va l ve operates each time the star t er is energ i zed and is calibrated to deliver f u e l at the f o li ow i ng rates:

B21F : 0 .

115 liter / min at

4 .

5 kp / cm '

B27F : 0 .

165 liter / min at

4 .

5 kp / cm '

Thermal time switch

Co n tro i s current to the ca Id start in j ector and is inf lu enced by:

t h e te m perat ur e o f th e eng i ne coola n t.

This ca u ses termina ti an of ca Id s t a r t fuel injec tia n at eng i n e t emperatures:

35 " C or higher for B21 F

15 "

C or higher for B27F

a h eating co il act i ng on the bi-meta I switch.

Th is provides for a maxi m u m in j ection t i me of

7.5 seconds at 20 ' C. which decrea ses at h ig h er tempe r atures.

Auxiliary air valve

B yp a sses t h e t h rott l e va l ve and supp l ies additio n al air during warm-up. Contains an a i r valve which i s cont r a li ed by a bi meta li ic spring.

I t is in f l u enced b y air temperature and a heat i ng coi l.

Completely opens at

-30 '

C

Completely closes at

+

70 ' C

Starting at

+

20 " C it will close af ter 5 minutes warm-up_

6

G r oup 2 4

Fu e l system

el Sy s tem , F au /t T

Special T -

2901

5011

5014

5015

5032

Pinchers for fuel line

Pressure gauge

Measuring glasses

Wrench

Nipple , used with 5011

Special Tools

5102

5116

5151

5170

9934

W renc h

Hose , used with 5011

Valve and hose kit

Test relay

Test instrument

2901

Pinchers

for fuel line

5011 Pressure gauge

5014

Measuring glasses

Applied for 821 F

1 08985

5014

Measuring glasses

Applied for 827 F

I I • i ,

123266

5032 +5116 Nipple and hose

Applied for 821 F

,..-~

5116

5011

--.::c

~

J

~-==:

.

'

5032

5032+5116 Nipple and hose

Applied for 827 F

112729

Group

24 .

Fuel system

'17746

7


Special T ools -

5015 Wrench

821 F CO adjustment

5170 Test relav

F or test i ng operation of the electronic fuel pump relav

5102 Wrench

827F

CO adju s tment

5102

' 1 9 834

If test relav is not available , assemble from e x isting part s

1215613

123 1 89

5151

Valve and hose kit

For CO meter

5151

958216

5b

123190

9934 Injector tester

821

8

Group 24

Fuel s y s tem

.~ ti:-

.

....

.

113 7 82

el System, Fault Tra ci ng

E x ploded view ,

8 2 1

F -

el System, 821 F - Exploded

Vie~

FUEL FILTER

START INJECTOR

AUXILIARY AIR VALVE

to the fuel tank

CONTROL PRESSURE

RE';ULAHJ.

SPEC

USA

(high altltude)

\

\

\

\

AIR

\

r-~~------~\

\

\

\

\

FREWENCY

(vehicles equipped w. Oxygen Sensor

Feedback system)

Group 24

Fu e l sys tem

125916

9

CJ System, Fault Tracing

- Exploded, view, 827F -

el System, 827F - ExplodedView

REGULATOR

\ ~

\f;M~

I

~

I

I

I

~~I

III

I r -----

I

I

.

III~

I

I.

~

to the

II t:uel tank

I

FREQUENCY

VALV E

('IIi th Oxygen

Sensor Feedback tem)

125917

10 Group 24

Fuel system


Quick Reference Guide -

Quick reference fault tracing guide

Symptoms

Note :

Numbers in Symptom columns represent order of likely occurance .

Ca u ses othe r than CI fuel :

1 Battery weak

2 1 1 3 2 1 1 1 1 1 1 g n i t i on

10 2 2 4 3 2 2 2 2 2 Compression

! - - f - -

----jf---1 ---r-- f--I - - - - - - - - - - .

-

15

16

7

6

5 6 8

6

8 7

6 3

6 10 Vacuum leaks

Extreme eald

5 B CO

11 4

12 5

I - -

13

14

3

5

8

•

•

2 4 7

5 5

-+--

-1--1--

6 9

Emi ssi on contr o i system s:

EGR •

7

5 6 Oxygen sensor feedba c k s ystem 01-07

-

I -

! - f - - - . - - - -

7 Catalyti c converter *

Evaporati v e contral

*

3

4

3 4

5

3

3

A ir s u pply :

Air intake system

Air induction system

Air flow sensor

•

•

•

Dl-D5

E l EB

4

6

4

Fuel supply :

Fue l pump operation

Main re l ay operation 11976 77 only )

Fuel leakage

A l A 17

C2

Bl

7

3 5

Inj ec tors : ea l d s t art injector , thermat time switch

In j ec t ors

Fl-f9

Jl Jll

3 5

4

4

4

7

Fuel system pressures:

Line and rest pressure s

Controi pressure

Info

Hl-H13

IHll

• Refer to appropriate Servi c e Manual

11

Group 24

Fuel system


-Symptoms-

Symptom - cold engine difficult to start or no start

Probable cause

Remedy

Operate starter and nate engine cranking speed.

If too slow, check conditian of battery and connections .

Battery weak

\ /

Weak or no ignition spark

\ /

Air intake system blocked

\ /

Fuel supply

\ /

Perform simple checks:

Fuel pump operation

Refer to ap. A 1-A3

Air induction system

821F - ap. D1 D2

827F ap. D3-D5

Main relay operation

1976 1977 only.

Refer to ap . C2

Cold start injector

Refer to ap. F 1 -F9

Air flow sensor plate

821 F ap. E 1-E4

827F - ap. E5 ES

Continued next page

Check by holding spark plug wire 5 / 16" to 3 / S"

(S 10 mm) away from engine block while engine is cranked. A strong spark should be noted .

Check air filter. Replace as ne cessary .

See below:

Injector operation

Check that injectors whine with air flow sensor plate lifted (depressed on 827F ) and fuel pump operating .

If all injectors are quiet, check pressures in the fuel system as follows :

Line and rest pressures:

-ap . H1-H13

Controi pressure :

- ap. 11-111

~

12 Group 24

Fuel system


-Symptoms-

Symptom - cold engine difficult to start or no start

eontinued from previous page

, /

Malfunction in system other than el fuel

See below:

Ignition

Check ignition timing

eompression

Check engine compression

~

mission

controi

EGR

Check for stuck EGR va lve or refer to Emiss ion

System Repair and Maintenance Manual ,

TP 11121

Oxygen Sensor Feedback System (Lambda sond)

Eliminate system using op. O 1-07 or refer to

Oxygen Sensor Fe edback System Manual.

Catalytic converter

Check for damage and / or blockage.

Evaporative controi

Check for stuck valves or vacuum leaks. (Refer to

Emission System Repair & Maintenance ManuaL)

Other possible trouble areas ...

Vacuum leaks

In spect all hoses and connections.

\ /

Extreme cold

In sta ll winterizing kit.

el fuel system malfunction

Troubleshoot entire CI fuel syste m.

P erfo rm procedura l operations with in Groups A through J in this manual.

Effe ct repair using the foll owing Repair

&

Maintenance Manuals, as necessary:

B21 F - TP 11121

B27F -

TP 11122

Group

24

Fuel system

13


-Symptoms-

Symptom - warm engine difficult to start

Probable cause

Ignition system

\ / eompression

\ / el fuel system rest pressure and pressure drop

V

EGR system

\ /

~

Oxygen sensor feedback system

(Lambda sond)

V

Remedy

Check ignition timing.

Check engine compression.

Refer to op. H l H 1 3.

Check operation of EGR valve or refer to Emission Repair & Maintenance Manual,

TP

11123.

Eliminate system using op. O l-D7 or refer to

Oxygen Sensor Feedback System Manual.

el fuel system malfunction

Troubleshoot entire CI fuel system.

Perform procedural operations within Groups A through J in this manual.

Effect repair using the following Repair & Maintenance Manuals, as necessary:

821 F -

TP

11121

827F -

TP

11122

~ I

14 Group 24

Fuel system

el System , Fault Tr acing

-Symptoms-

Symptom - cold

& warm engine difficult to start

Probable cause

Ignition system

\ /

Compression

\ /

Air induction system

Air flow sensor

\ /

\ /

CI fuel system line pressure

\ /

Remed y

Che ck ignition timing.

Check eng ine compression.

B21F -op. 01-0 2

B27F op. 03-05

B 21 F op. E l-E4

B27F - op . E5-EB

Ref er to op. H l-H4

.

CO adjustment

B21F

B27F

op. K l K3

- op . L l L7

B21F w / Lambda sond op. Ml M7

B27F w / L ambda sond op. Nl-Nll

Vacuum leaks

V

\ /

Inspect all hoses and connec tio ns.

CI fuel system malfunction

T roubleshoot entire CI fuel syste m .

Perform pro c edural operations within Groups A through

J in this manual.

Eff ect repair using the following Repair & Main tenance Manua l s as ne cessa ry:

B 21 F TP 11121

B27 F TP 111 22

Group

24

Fuel sys tem

15

e l System, F au l t T raci n g

Symptoms -

Symptom - erratic running engine / cold or during warmup

(Start all chec

k

s with engine cold

.

'

Probable cause

Remedy

el fuel system co

n

troi pressure

V

Refer to op . 11 11 1 .

EGR system

Check operation o f E GR valve or refer to E mission Repai r & Maintenance Manual,

TP

11123 .

Ign

it

ion s

y

stem

V

\ /

eompression

Vacuum leaks

\ /

\ /



Check all hoses and connections .


Troub l eshoot entire C I fuel system.

Perform procedu r al operations within Groups A t h roug h

J in this manual.

Effect repair using the following Repair & Main tenance Manuals, as necessa r y:

B2 1 F -

B27F -

TP

11121

TP

1 1 1 22

16 Group 24

Fuel system


-Sympto ms-

Probable cause

Symptom - erratic running, warm engine

Remedy

el fuel system controi pressure

Ignition system

\ /

\ / eompression

\ /

EGR system

\ /


(Lambda sond)

\ /

Vacuum leaks

\ /

Refer to ap. 11 111


Check engine compression

Check operation of EGR valve or refer to Emission Repair

&

Maintenance Manual, TP 11123 .

Eliminate system using op. 01-D7 or refer to





Perform procedural operations within Groups

A through

J in this manual.

Effect repair using the following Repair & Maintenance Manuals, as necessary:

821 F TP 11121

827F - TP 11122

Group

24

Fuel system

17


Symptoms-

18

Symptom - Erratic running, engine cold

& warm

Probable cause

Ignition system

Remedy

Check ignition timing .

-

\ /

Compression

Check engine compression .

\ /


\ /

-

CI fuel system controi pressure

821F op. Dl

827F op . D3

Refer to op. 11-111

\ /


(Lambda sond)

\ /

Eliminate s ystem using op . 01-D7 or refer to


ca adjustment

821F op. Kl K3

827F op. L l-L7

821F w / Lambda sond -op . Ml M7

827F w / Lambda sond - op . N l--N 11

Throttle valve(s)

V

\ /

EGR system

Vacuum leaks

V

V

821 F reler to op. D2

827F reler to op. D4-D5

Check operation 01 EGR valve or reler to Emission Repair & Maintenance Manual , TP 11123 .




Perlorm procedural operations within Groups A through J in this manual.

Effect repair using the lollowing Repair & Maintenance Manuals , as necessary :

821F-TP 11121

827F TP 11122

Group 24

Fuel system

el System, F ault Tr acing

-Sy mptoms -

Symptom - erratic running engine and high fuel consumption

(Start all checks with a cold engine.!

Probable cause Remedy

Ignition system


\ /

Compression

\ /

Cold start injector leaking

\ /

CI

fuel

system controi pressure

\ /


(Lambda sond)

V


Refer to op. F 1-F4.

Refer to op . 11-111.

Eliminate system using op. 01-07 or refer to

Oxygen Sensor Fe edback System Manual.

CO adjustment

B21F -op . K1-K3

B27F op. L 1 L7

B21F w / Lambda sond - op . M1 M7

B27F w / Lambda sond op. N 1 N 11.

V

EGR system

Vacuum leaks

V

V

Check operation of EGR valve or refer to Emission Repair & Maintenance Manual , TP 11123.

Check a ll hoses and connections.

CI

fuel

system malfunction

T roubleshoot entire CI fuel system.

P erform procedural operations with in Groups A through J in this manual.

Eff ect repair using the following Repair & Maintenance Manuals. as necessary :

B21 F TP 1112 1

B27F-TP 11122

Group

24

Fuel system

19

e l System , Faul t Tracing

Symptoms -

20

Probable cause

Symptom - rough idle

R emedy

Ch e ck ignition tim ing.

Ignition system

Compression

V

Check e ngine compressian .

Engine cylinders

\ /

Injectors

\ /

Check ignition spark at each cylinder.

Check injection at each cy li nder , see ap . J l-J 10.

B21F ap. Kl K3

B27F ap . L 1 L7

CO adjustment

Vacuum leaks

\ /

\ /

B21 F w / Lambda sond ap. M 1 M7

B27F w / Lambda sond ap . N l N 11

\ /


B21 F ap . 01

B27F ap . 03

\ /

Air flow sensor and / or fuel distributor

B21 F - refer to ap. E 1-E4

B27F refer to ap . E5-E8

binding or seizing

\ /

-

EGR system

Che c k operation of EGR valve or refer to E mi s s ion Repair & Maintenance Manual , TP 11123.

Check all hoses and connections.


T roubleshoat entire CI fuel s y stem .

Perform procedural operations w ithin Group s A throu g h J in this manual.

Eff ect repair using the following Repair & Main tenance Manuals, as necessary:

-

B21 F - TP 11121

B27F TP 111 22

Group 24

Fuel system

e l System, F ault T racing

-Symp t oms-

Symptom - low top speed (poor engine performance)

P robable cause

Remedy

-

Ignitian system

Check igni ti on t i ming .

Compression

\ /

Throttle valvels)

\ /

C h eck e n g in e compressian.

B 2 1 F refer to ap . D 2.

B2l F refe r to op. D 4D 5.

\ /

Fuel supply (line pressure)

\ /

Refer to ap. H 1 H 4.

CO adjustment

B2 1 F -ap. K 1 -K3

B2l F ap. L 1 L l

B21 F w / L ambda sond op . M 1-Ml

B2lF w / Lambda sond ap . N 1-N 11

Vacuum leaks

V

\ /

Catalytic converter

\ /

Check all hoses a nd connections.

Check for da m age and / or b l ockage.

CI fuel system malfunct

i

on

Throubleshoot entire CI fuel system.

Perform procedural operations within Group s A through J i n th i s manual.

E ffect r epai r us i ng the fo ll owing R epa i r & Main -

tenance Manua l s , as n ecessar y:

B21 F T P 1 1 121

B2l F TP 11122

Group

24

F uel system

2 1

el System, F ault Tracing

Symptoms -

Probab l e cause

Ignition system

V

Compression

Symptom - high fuel consumption

{Start all checks with engine coldJ

R emedy


V

Air cleaner

V

Externai fuel leakage

\ /

I

Cold start injector leaking

\ /


( Lambda sond)

V

CI fuel sys t em controi pressure

\ /

Check engine compressian.

Check for blockage.

Perform v i s ual check, ap. Bl .

Refer to ap. F l-F4 .

Eliminate syste m using ap. O

1-07

or refer to

Oxygen Sensor Feedbac k System Manual.

Refer to ap . 11-111.

CO adjustment

B21F -a p . Kl-K3

B27F ap. L l L7

B21 F w / Lambda sond ap. M l-M7

B27F w / Lambda sond - ap. N l N 11

~

~

•

•

•

•

V

EGR system

Check operation of EGR val v e or refer to Emission Repair & Maintenance Manual. TP 11123 .

Vacuum leaks

\ /

V

Check all ho ses and connections.

•

CI fuel system malfunct i on

Troubl es hoat entire CI fuel sys tem .

Perform procedural operations within Groups A through

J in this manual.

Effect repair using the following Repair & Main tenance Manuals. as necessary :

B2 1 F TP 11121

B27 F TP 11122

22 Group 24

Fuel system

el System , F aul t Tr acing

Fu e l pump-

Fault analysis

Fuel pump operation - simple check

Fi rst check appropriate mechanical, e l ectrical and emission controi system i te ms as indi cated prev i ously before p r oceeding w ith the fo ll owing trouble analysis .

Al

Set ignition switch to ON

.

(Do not attempt to engage starter at this time.!

1978

123267

A2

1976-1971 Vehicles

Remo ve the connector from the air flow sensor to enable fuel pump operation.

123 267

A3

Sb

1978 Vehicles:

Install test relay 5170

.

(This relay simulates e l ectronic module pul ses from the ignition system.)

123266

Listen

Li sten at rear of vehicle for fuel pump motor operation. ( Thi s test shou ld be conducted in a relative l y quiet work a r ea.)

Group

24

Fuel system

23


Fuel pump-

Fuel pump inoperative

First check appropriate mechanical, electrical and emission controi system item s as indicated previously before proceeding with the following trouble analysis.

Reference wiring diagram at rear of this manual.

1976-1977 Vehicles

\(;/

Check fuse No, 7.

(On 1976 vehicles check also fuse No . 5.)

J1~~-

E8~

E 9 3

E:l03

Fuse blown or defective.

I

Fuse not

I defective~

Check circuit for shorts.

Replace blown fuse.

Ell.31

E

1231

______

__

____

~========~

________

~'~ 23~2~75~~\~

A5/

/

---------------------------------

heck for voltage at the fuel pump.

(Measure at the connection in the trunk.)

( ,

I

VOltage~

defective fuel pump,

~

\L )~ ) ~

I

_ _ _ _ _ _ _ _ _ GO

_

12 3276

_

voltage

_ damaged wire between con nection in trunk and pump, or bad ground connection.

Check for voltage at terminal 87 on the pump relay.

Relay with ground lead (black wire)

= pump relay.

123277

I

r

----1 [>

Indicates defective wire or connector between pump relay and fuel pump.

No voltage

I

24 Group 24

Fuel system


Fuel pump-

__________ ________ __________

~\ A7 ~Z----------------------

V

,I'

\

I ,

-'

,

...

--....

,

......

~

123277

Check for voltage at terminal 30 / 51 on the pump relay,

I

VOltage r---{:>lndicates defective w ire between fuse No. 7 and pump relav.

No voltage

Check for volta ge at terminal 86 on the pump relay .

! Voltage !1-----1[:>check the re lav ground connection. If ground is O K re place the pump relav.

No voltage

12 3278

Check for voltage at terminal 30 on the main relay.

! Voltage r---{:>Indicates defective wire between the ma," relav and the pump relay.

No voltage

12 3279

Group

24

Fuel system

25

el System , F au lt Tr acing

F uel pump-

________

__

______

__

____

____

~

Al0

~7

---------------------------

V

Check for voltage at terminal 87a on the main relay.

I

Voltage

~ In dicates

defec t ive main relay.

123279

I NO

vOltage

~

lndicate

s defective wire to terminal 87a.

End of fuel pump fault tracing 197 6 1 977 ve hicles .

1978 Vehicles

--------------------------

---

--~--------------

--

-------------------

E:

1:31

E231

E 3

E

:431-+--t

~5

H;.3t-i-r

E 6

E' 93

E lD :='

E

l13J

E

1231

Check fuses No. 5 and 7 .

Fuse blown or f----j

Check circuit for shorts.

Replace blown fu se .

,

,

Check for voltage at fuel pump.

(Measure at the connection in the trunk.l r.

vvo~lj;ta~g;;:e

;.]I----c:>

Indi cates de f ective fu e l pump . dam aged wire between connections in trunk and pump, or bad ground connection.

No voltage

12328 0

\J

-----------------------------------

26

Group 24

Fuel system

el Sys tem , F ault Tradng

- Fuel pump -

------------

----

----------------

4\~

---------------------------

Check for voltage at terminal 87 on the

(main) relay (yellow wire) .

I

VOltage ~ l ndicate

s defecti v e w ire b e t ween (main ) r e l av and fuel pump.

No voltage

1 2328 1

7


(main) relay (red wire) .

I

No vOltag 9f----t>lnd i cate s defective wire between (main) r e l av a nd fu se

NO.7

.

12 3

282 , , -:,::-,

____________

__

________

__

____________

~A'5/------------------------------

+I ..

~~r---r_-.,


(main) relay (blue/red wire).

I

No vOltage i--!>lndicates defective wire bet ween re lav and fuse No. 5 .

Voltage

123283

Group

24

Fuel system

27

el Sys tem , F ault Tr acing

Fuel pump-

\

(!Z

--------------------------

+

Ground the (main) relay (terminal 31 black wire).

Check if fuel pump opera tes .

Fuel pump oparates

Indicates defective

wire.

ground

123284

Check for pulsating

volta g e

at terminal

31b on the (main) relay (white / red wire).

j VOltage f-j --[::> dicates defeetive rela y. j

No

vOI

~lndieates

wire between (main) relay and ignition eo il , defeetive test relay or ignition system.

12 3285

End of fuel pump fault tracing 1978 vehicles .

28 Group 24

Fuel system

CI System, Fault T racing

Fuel supply -

Fuel supply

Som e 1976 models and all 1977-78 models are equipped with a fuel feed pump (tank pump) . With this arrangement, the line to the fuel pump is kept under approximately 0.2 kp /c m ' (=3 psi) pressure. This will eliminate risk of vapor pockets forming in the fuel line to the main fuel pump.

Line pressure too low

First check appropriate mechanical , electrical and emission con troi system items as indicated previously before proceeding wit h the follo wing trouble analysis.

81 j

. j j

•

Check for leakage between the fuel pump and the fuel distributor (externai leakage).

Also check for leakage at the fuel accumulator .

1978: Remove the fuel tank cap to release any overpressure in the fuel tank. Disconnect the hose

(fuel accumulator-fuel tank) from the fuel accumulator. Check the fuel accumulator for leakage and re-install the hose.

Repair as necessary.

12 3 2 9 0

82

Check fuel feed (tank) pump

Connect an ammeter between the interference suppressor and the tank pump.

Set ignition to ON (activate fuel pump).

(See op. A 1-A3) .

Correct current flow is 1-2 amps.

No current flow:

Check fuse in trunk.

for voltage to the fuel feed pump .

Incorrect current flow :

Check the fuel feed pump and filter. If current flow is below normal , check the fuel laval.

113681

Group

24

Fuel system

29


Fuel s u pp l y -

83

-

I

~' l

+-

~

I

0.8 liter

Check fuel pump capacity

R emove the fuel tank cap to release any over -

pressure.

D isconnect the re turn lin e at the connection in the engine compa rtm e n t. H old the disconnected end of the return line over a measuring gla s s .

Set igniti on to ON (act i vate fuel pu mp) for 30 seconds and then switch OFF aga in.

There s hould be a minimum quantity of 0.8 li ter fuel in the measuring glass.

Incorrect

fuel pump

capacity :

Check f uel filter. If se r viceable , the n test syste m using a new fuel pump.

If

this does not remedy th e problem , c heck fuelline s and

fu e l

flow sensor.

12 3 29 5

Excessive line pressure

Fir st check appropriate mechanical, electrical and emission controi system items as indicated previously before p r oceeding with the followin g trouble analysis.

84

B21 F

Check fuel return line

I gnit i o n swi t c h OFF.

Remove fuel tank cap to release any overpressure from the fuel tank . Dis connect the return line at the fuel distributor.

Apply compresse d air at r educed p re ssure using

an a ir hose.

Clean / replace the fuel r eturn hose , as neces s ary.

Check holl ow screw (banjo bolt) f or b l ockage .

12 5 9 23

30 Group 24

Fuel system


Electri ca l supply -

Electrical supply

Fir st check appropriate mechanical , electrical and emission contro i system items as indicated p r evious l y befor e proceeding with the foll owi ng trouble a n alysis. el

E: ' ~

E: 2

E33

E: 4

[

~!3+1

I-

E6

E 93

E: 103

E ll~

E 12

Check fuses

1976-77 :

Fu se No. 5 , 8 amps.

P rotects the main relay and the fuel pump relay

c ircuit s.

Fuse No . 7 , 16 amps.

Protects the f uel pump, fuel feed pump, controi pressure regulator and the auxiliary a ir va lv e cir-

cuits.

1978 :

Fu se No. 5, 8 amps.

Protect s the electronic fuel pump relay circuit.

Fu se No . 7 , 16 a m ps.

Protect s the fuel pump, fuel feed pump . controi pressure regulator and the auxiliary air va lv e c ircuits.

1 23275

e2

~---

I

.

,

r-----.

,

"'"

Check main relay (1976-1977)

Operate the star te r motor. Check f or voltage at m ain re l ay terminal 30 / 5 1 wit h the star ter motor energized .

If there i s no voltage , check f o r voltage at main rela v terminal 87 with the starter motor energized .

No voltage:

Indicat es that the wire from the s tarter m otor to main re l av termin a l 87 is defective .

Voltage :

Indi ca t es that the main rel av is defective.

125 2 1 9

Group 24

Fu el system

31


Air intake -

Air intake / throttle valve

(B21F)

First check appropriate mechanical , electrical and emission controi system items as indicated previously befare proceeding with the following trouble analysis .

DI

Check air intake system for leakage

Check all hose connections and O rings. There must be no air leakage between the air flow sensor and the engine.

Check that there is no leakage at the injector ho l d ers or at the cold start injector.

Carefully check the rubber be ll ows between the air flow sensor and the intake manifoid.

Repair as necessary.

120756

D2

Throttle valve

Check that the throttle valve is securely attached and correctly installed .

1 25 91 8

32 Group 24

Fu el system


Air intake -

Air intake / throttle valves

(B27F)

First check appropriate mechanical, electrical and emission contro i system items as indicated previously before proceeding with the following trouble analysis.

D3

Check air intake system for air leaks

(visual inspection).

Check:

1 . Auxiliary air valve hose connections.

2. Cold start injector hose connections.

3. CO adjustment plug.

4. Remaining hose connections.

5. For leak s in O rings and gaskets.

04

Remove the front intake manifold to check the throttle valves.

05

Throttle valves.

Check that the throttle valves are securely attach ed, correctly centered and do not bind.

Use new O-rings and gaskets when re installing the front intake manifoid.

Group

24

Fuel system

33

C/

System, F ault Tracing

Air flow sensor -

Air flow sensor

(B21F)

Fir st check appropriate mechanical , e l ectrical and emission controi sys tem it ems as indi cated previous l y before proceeding with the following trouble ana l ysis.

E1

34

o c

C o r rect Wr o n g

I

Check that air flow sensor plate is centered in venturi

.

The air f l ow sensor plate must not touch the venturi at any point or have excessive side clearance.

In c orr ec t po s iti o n :

Check that the lever has no si de play. L oosen the cen ter sc rew and adjust plate posit i on.

108604

E2

Check ai

r

flow sensor plate rest position

.

T he top s i de of the air flo w sensor p l ate should be flush with, or no more than 1 mm 10.04") be l ow , the lo we r edge of the cone.

In c orr e ct p o sition :

Adjust by squeezing together or straightening the wire b r aeket "A" underneath the air flow sensor plate .

108603

E 3

Check that the air flow sensor does not seize or bind.

R aise the ai r f l ow se n sor plate and the n r e l ease it .

T he plate shou l d immed i ate l y return to its initia l position.

NOTE :

The controi pressu r e will cause resistance when the p l ate i s l ifted. Thi s must not be confused with jamming.

1 1 9817

Group 24

Fuel system

E

E

N

L!)

O

9 9

O g


Air flow sensor -

E4

In ca se of incorrect operation.

Remove the air flow s ensor and fuel dis t ributor assembly.

Overhaul / replace a s necessary. See Repair &

Maintenance Servi c e Manual , TP 11121.

1 2 0784

(B27F)

E5

Check that air flow sensor plate is centered in venturi.

The air flow sensor plate must not touch the ven -

turi at any p o int or have excessive s ide clearance.

Incorrect position :

Check that the lever has no side play . Loosen the center screw and adjust plate position.

1 21018 2V

E6

Check air flow sensor plate rest position.

The distance shown should be O-D.5 mm

(O-D.02").

If misaligned, check plate lever for distortion and position of contact pin.

Check that the plate stop does not touch the plate.

Contact pin is adjustable (inward) using a drift and mallet. Light to moderate tapping is sufficient to mo v e pin. Removal of the air flow sensor is ne cessary to drive pin outward.

1 210 18 2X

Group 24

Fuel system

35

el System, Fault Tracing'

- Air f/ow sensor -

E7

Check that the air flow

sensor

does not seize or bind,

Depr ess the sensor plate and release it . The plate should return immediately.

NO TE :

The contro i pressure w ill cause so me resistance when the sensor plate is depressed. Do not con fuse this resistance with seizing .

Possible faults :

Lever seizes in hou sing.

Le ve r pivot seizes in hou sing.

Plunger binds.

E8

In case of incorrect operation:

Remove the air flow sensor and fuel distributor assemb l y.

Overhaul / replace as required. See Repair

Ma i ntenance Service Manual ,

TP

11122.

&

36 Group 24

Fuel system

CI System, Fault Tracing

Cold start injector -

Cold start injector / thermal time switch

First check appropriate mechanical, electrical and emission contral system items as indicated previausly before praceeding with the following trouble analysis.

Fl

Disconnect the white wire fram terminal 1 on the ignition coil (safety measure).

Set ignition switch to ON,

12 3298

F2

Sb

Operate the fuel pump.

1976-1971:

Remove the connector from the air flow sensor to start the fuel pump.

1978:

Install test relay 5170 to start the fuel pump .

1232 92

123 272

F3

Remove cold start injector from intake manifoid,

B21F:

Reconnect the graund wire to one of the retaining screws for the cold start injector to allow cold start injector to function.

Check whether engine is warm (above +35" C =

109 " F) or cold.

Warm engine:

proceed to ap. F8.

eold engine:

proceed to next operation.

Group

24

Fuel system

37

CI System , F ault Tracing

Cold s t art irljector -

38 Group 24

Fuel system

F4

Check for cold start injector leakage,

A fuelleak may cause erratie running and high fuel eonsumption.

The eold start inieetor must not l eak more than 1 drop / minute, ot herwise it shou ld be replaced.

1 203 7 5

F5

Cold engine

Check that the eo ld start injeetor injects fuel when the starter motor is energized.

At ambient temperature of 20" C

(-4"

F lor co lder, the co ld start injector should inject for about

7.5 seconds. The injection period gradually de c r eases as the temperature rises , and stops a l to gether at temperatures above + 35" C (109 " Flor af ter engine ha s been cranked a fe w t imes in suc -

cession.

1 2 0373

1 20374

F6

Fuel not injected. engine cold :

Check for vo ltage at the eold start injector when the starter motor is energized.

Voltage :

Indi cates defeetive eo ld star t injector .

NOTE :

If engine has been cranked several times in s u ccessio n t he thermal time swit c h will cut out and a no voltage condition will appear.

No voltage:

Proceed to ne x t op.


- Cold start injector -

Fl

12 3 273

No voltage in op. F6:

Check for voltage between the connector and the chassis with the starter motor energized.

1 976 1978 = blue / yellow cable - chassis.

Voltage:

Indicates thermal time switch cutout or defective thermal time switch. Check also for defective wire between thermal time switch and cold start injector.

No voltage:

Indicates defective wire between starter motor and cold start injector.

F8

Warm engine

Check if the cold start injector injects fuel when the starter motor is energized.

Th e injec t or must not inject fuel when the engine is warm l above + 35 ' C

=

112 '

F).

If fuel is injected with warm engine, there may be two causes:

1. Thermal time switch defective.

2. Cold start injector defective.

To establish correct cause , proceed to next o p.

1 20375

F9

Cold start fuel injected, engine warm:

Remove the connector from the cold start injector to eliminate influence from the thermal time switch. If there is injection when the starter motor is energized , the cold start injector is defective.

No injection at this time indicates a defective ther mal time switch.

1 2327 4

Group

24

Fuel system

39

1..

1 JY;:' L t::III, rdUIt IldL " IIIY

eold s t art injector -

Quick reference for possible problems involving cold start injector

Cold engine

Condition :

Cold start injector does not inject fuel when the starter motor is energized:

Act i on :

Check for vo ltage to the co ld s tart injector.

Vo ltag e:

I ndicates a defective co ld start injector.

N o vo l tage :

Ind icates defective thermal time switch o r electrical w ire s.

Conditi o n :

The cold start injectors operate but the e n g in e does not s tart.

Ch ec k:

- Fu el system for leakage .

Auxiliary air v a l ve.

Contral pressure.

Engine at normaloperating temperature (warm)

V

1

Cond i t i on :

Th e co ld s tart inj ec tor opera tes when engine t e mperature is above 35 " C (lOg" F ) :

Ac t ion :

Di sconnect the w ire connec tor at the co ld start inj ec tor .

Inje c tor still inj ec t s: rep l ace it.

Inje ct ion stops: indicates defective thermal tim e sw it c h .

Condi t ion :

Cold sta rt in jector does not operate and engine does not s t a rt.

C h eck:

Leaking fu e l system.

Inj ec tors l eak i ng.

I ncorrect line pressure.

Incorre ct rest pressure.

Incorrect CO adjustment.

40 Group 24

Fu e l system


Auxiliary air valve -

Auxiliary air valve

First check appropriate mechanical . electrical and emission controi system item s as indicated previously before proceeding with the follo w ing trouble analy s is .

GI

12 0 76 2

Check auxiliary air valve.

The auxiliary air valve should be partly open at room temperature . fully open at -30 ' C( = -22 ' Fl and fully closed at +70 ' C

(=

158

0 minutes of engine operation.

Fl . or af ter 5

NOTE:

Af ter heating up . it may take an hour for the auxiliary air valve to return to a position which corres ponds to the ambient temperature.

For B27 F: Use mirror and light to check.

1 20388

G2

Check operation of bi-metallic spring

(with engine off).

For this check , the wires at the auxiliary air valve should be connected , ignition ON and the fuel pump running (see op. A 1 A31. (The au x iliary air valve and controi pressure regulator are also energized .

l

The valve should be fully closed af ter approximately 5 minutes of operation .

If not, tap lightly on the valve as engine vibrations normally contribute to closing.

119818

\

Group 24

Fuel system

41


A uxiliary air valve -

/

G3

If the auxiliary air valve still does not close:

Check for voltage.

Remove the wire connector and check for voltage across the connector terminals.

No voltage:

Indicate s defective wire or voltage supply.

1 198 19

G4

Voltage a cross the wire terminals , auxiliary air valve not operating :

Check resistance of auxiliary air valve.

B21 F: approximately 49 ohms

B21F : approximately 21 ohms

No reading, or incorrect reading , indicates the auxiliary air valve is defective.

120763

42

Group 24

Fuel system

I


- Line and rest pressure -

Line and rest pressure

First check appropriate mechanical , electrical and emission controi system items as indicated previously before proceeding with the following trouble analysis.

Prepare for test

H1

Connect pressure gauge 5011 between controi pressure regulator and fuel distributor .

1 17 7 4 6

H2

Disconnect the white wire from terminal 1 on the ignition coil (safety measure).

Set ignition switch to ON .

1 23298

H3

S b


1976-1917:


1978:

Install test relay 5170 to operate the fuel pump.

1 2329 2

Group

24

Fuel system

43


Line and rest pressure -

450-530 kPa

(4.5-5 .

3 kp / cm')

Check line pressure

170 kPa

(1.7 kp / cm 2

)

H4

Check line pressure

Set the valve on tool 5011 in position 1 (toward the fuel distributorl.

Line pres s ure should be:

4.5-5.3 kp / cm 2 = 64-75 psi.

1 20384

Incorrect readings

Excessive pressure:

Check that the fuel return line from the fuel distributor to the tank is not restricted , see ap. B4.

Line pressure too low:

Refer to ap . B 1 "Fuel Supply " .

Check rest pressure

H5

Check the rest pressure

Place the valve on tool 5011 to position 2 (right angle to the hoses) and set ignition switch to OFF .

Nate the rest pressure when the reading has stabilized .

The rest pressure should be: min. 1.7 kp / cm 2

=

24 psi.

, I

1 2 07 6 4

H6

Check the rest pressure for a 1 minute period,

It must not drop.

No drop - proceed to ap. H9.

44 Group 24

Fuel system

I I I 1 1

20min.

100kPa

(1

kp/cm')

1111 1



Hl

Pressure drop:

Check the rest pressure during a 20 minute period.

Af ter 20 minutes there sh ou Id be a remaining pressure of: min. 1 kp / cm 2 = 14 psi

120393

Ha

Pressure drops too low:

Check the rest pressure with the valve on tool

5011

in position 1.

The controi pressure regulator must be warm.

Repeat op. D5 (run fuel pump) to build up pressure in the system.

Set the valve on too I 5011 to position 1 (toward the fuel distributor) and note the pressure.

H9

Check the rest pressure with the valve on tool

5011

in position 3.

If necessary. run the fuel pump again to build up pressure in the system.

Set the valve on too I 5011 to position 3 (towards the controi pressure regulator) and note the pres-

sure.

12 5 9 21

Alternative readings

Consistent but incorrect rest pressure in position 1 and 3.

Proceed to op. H 12.

Rest pressure drops or is incorrect in position 3.

First check that the controi pressure regulator is warm . Test using a new controi pressure regula tor.

Rest pressure drops in position 1.

Proceed to op. H 10.

Group 24

Fuel system

45



450-530

kPa

(4 .

5-5 .

3 kp / cm')

'-'1

46 Group 24

Fuel system

1978

H10

Check for leakage between fuel pump and fuel distributor (externaI leakageJ .

Set the valve on too I 5011 to position 1 ( tow a rd the fuel distributor).

Check for leakage (also at the fuel accumulator) .

1978

modeis: Remove the tank cap to release any overpressure in the fuel tank. Disconnect the hose from the fuel tank at the fuel accumulator.

Check the fuel accumulator for leakage and reinstall the ho s e.

12 3290

' 23291

H11

Check the line pressure regulator for leakage,

Run the fuel pump to build up pressure in the system.

Remove the fuel tank cap to release any overpressure in the fuel tank.

Separate the return line ijunction at filter) and hold the end of the hose upward.

If fuel runs out of the hose, it indi c ates that the line pressure regulator is leaking. Replace the O-ring in the line pre s sure regulator. If thi s does not remedy the problem , replace the fuel distributor.

If the line pressure regulator is not leaking , the fuel pump check valve must be defective and should be replaced. This can be checked by blocking the flexible pickup line.

H12

Check and adjust line and rest pressures .

Line pressure:

Set the valve on tool 5011 to position 1 (toward the fuel distributor) .

Operate the fuel pump.

Read line pressure. It should be:

4.5-5.3 kp / cm '

=

64 75 psi.

12038 4

1 0 897 8


Line and rest pressure -

H13

Adjusting line and rest pressures.

Adjustment is made by adding or removing shims in the line pressure regulator.

Both the line and sh ut-off pressures are equally affected when adjusting. Both pressures increase if additional shims are installed and reduce if shims are removed.

Shims are available in two thicknesses:

0.1 mm (0 .

004 ")

= prov ides a pressure change of

6 kPa (0.06 kp / cm '

0 .

85 ps;)

0.5 mm (0.020'")

= provides a pressure change of

30 kPa

(0 .

3 kp / cm'

=

4 .

3 ps;)

The thicker shims should be used first when adjusting.

The thinner shims should be used when the line pressure is 490 kPa (4.9 kp / cm '

=

70 psi) or more, and the shut-off pressure is lower than

170 kPa (1.7 kp / cm '

=

24 ps;).

Group

24

Fuel system

47

CI System , Fault Tracing

Controi pressure -

Controi pressure

First check appropriate mechanical. electrical and emission contral system items as indicated previously befora proceeding with the following trouble analysis.

Prepare for test

11

Connect pressure gauge

5011

between contral pressure regulator and fuel distributor.

5116

--,~

5032

1 1 77 4 6

12

Disconnect the white wire from terminal 1 on the ignition coil (safety measure).

Set ignition switch to ON.

123298

13

Cold engine.

Disconnect the connector from the controi pres sure regulator.

Omit this op . if the test concerns engine with warm start problems.

1232 · 97

48

Group

24

Fuel system


Controi pressure -

14


1976-1971:

Remove the connector from t he air flow sensor to start the fuel pump.

1978 :

In s tall test relay 5170 to start the fuel pump .

123292

Check controi pressure.

15

Set the valve on tool 5011 to position 2 (at right angle to the hoses!.

Read the controi pressure.

120385

16

1.0

\-----1----+----+----1-,----1

o

32

50

68

C

104 F

Cold start problems.

The controi pressure regulator should be at a m bient temperature .

Proper controi pressure for different ambient temperatures can be obtained from the char!.

Pressure

too low:

Test using new controi pressure regulator .

Excessive pressure:

1. Set ignition switch to OFF.

2 . Remove the cap from the fuel tank to release any over pressure.

3 . Check if the return line from the controi pres sure regulator is blocked (refer to op . 64) .

4 . If the line is not blocked replace controi pre ssure regulator and re-check pressure .

Group 24

Fuel system

49


- ControI pressure -

17

Warm start problems.

NaTE:

With ca Id controi pressure regulator (engine), the fuel pump must run for 5 minutes before this check is accomplished.

During this time, the controi pressure regulator will heat up because of internai current flow.

Correct contral pressures:

821 F and 827F:

3.7 ± , D.2

kp / cm'

(3.5-3.9 kp/cm'

=

50-55 psi).

123302

Incorrect readings.

Excessive pressure.

Check that the return line from the contral pressure regulator is not restricted (see ap. 84).

Pressure too low:

See ap. 19-111.

kp/cm '

4.0

~~~-~-~~~-

3.7

,--I--4--l--I--+ --{,L'--

3 .

0

I--l~

2.0

1-1----,l"-

1.0 1--!~::.J-_ I---I_-1-_-I _-1_I---.J

O 10 20 30 40 50 60 70 80 ' C

~ W ~ % 1~

lU

1~ 1~ lMF

18

B27F only:

Vacuum controi test, engine running.

NOTE:

On 1977 model vehicles manufactured to "California" specifications, the vacuum hose should be vented to open air. Use portion of chart for "vacuum hose disconnected".

Check controi pressure with engine running with and without vacuum.

For in-between temperatures, obtain correct pressure in the chart.

With engine at normaloperating temperature, the controi pressure should drop fram 3.7 ± 0.2 kp/cm' to 3.3±0.2 kp/cm'

=

44-50 psi.

If the controi pressure is incorrect or changes to incorrect pressure, this indicates a defective control pressure regulator.

50

Group 24

FtJel system


- Controi pressure -

Controi pressure too low,

19

Check for voltage to the controi pressure regulator.

Measure the voltage between two pins on the

connector.

Voltage: proceed to op. 111.

No voltage: proceed to op. 110.

110

Check for voltage between the connector and the chassis,

1976-1978

= blue wire chassis.

Voltage:

Indicates defective ground wire to the chassis.

No voltage :

Indicates defective wire between the pump relay and the controi pressure regulator.

111

Check electrical resistance in the controi pressure regulator,

Resistance: B21 F

=

20-30 ohms

B27F

=

20-24 ohms.

Correct resistance :

This indicates that there is poor continuity in the

connector.

Incorrect resistance:

Replace the controi pressure regulator .

. 233 01

Group

24

Fuel system

51


Injectors , fuel distributor -

Injectors and fuel distributor

First check appropriate mechanical, electrical and emission controi sy s tem items as indicated previau s ly before proceeding with the following trouble analysis.

J1

Disconnect the white wire from t e rminal 1 on the ignition coil (safety measure).

Set ignition switch to ON.

B21F

B27F

1 2329 8

J2


1976-1977:

Remo v e the connector from the air flow sensor to operate the fuel pump .

1978:

Install test relay 5170 to operate the fuel pump .

1 23292

J3

Check injector operation:

Fuel pump operating.

NOTE:

Limit this test to short duration to prevent e x ces sive fuel from being injected inta the engine .

Force open the air flow sensor plate. The injectors should whine .

- The air flow sensor plate on the B21 F can be lifted using a pair of pliers or the too I used for adjusting CD.

B27 F uses downdraft system and the air flow sensor plate can be depressed using finger pressure.

The injectors are quiet:

Check all pressures of the Fuel System, see ap.

H 1-H 13 and 11-111 .

52 Group 24

Fuel system

Not mora than one drop in

15 seconds.

.. t



J4

When the air flow se nsor is allowed to close , the whine from the injectors s hould stop .

If they continue to whine , the controi plunger in the fuel distributor may have jammed.

123269

J5

Stop the fuel pump from operating and remove the injectors from the cylinder head.

125913

J6

Check the injectors for leakage .

Opera te the fuel pump a few seconds, then s top.

Check for leaks at rest pressure. Lift the air flow sensor plate to open fuel distributor slots. Ea ch injector must not leak more than one drop in 1 5 seconds.

If one injector leaks , see "Testing and Cleaning Injectors" in Service Manual TP 11121 (B21 Flor

TP 11122 (B27Fl .

If all injectors leak , the rest pressure may be too high .

Group 24

Fuel system

53

el System , Fault Tracing ,

Injectors , fuel di s tributor -

J7

Check fuel distributor for internalleaks.

Operate the fuel pump .

A s light s eepage may be ob s erved at injector tips but no drop s should form.

If injector leaks (drops form ed) , the fault may be :

1. Air flow sensor plate misadjusted (incorrect height) . Refer to op. E 1-E4 (821 F) or op .

E5-E8 (827F). in this manual.

2 . Fuel distributor plunger seizes. See op . J 1 O.

3 . Internalleaks in fuel distributor ' (faulty seals i in fuel distributor). The fuel distributor must not be disassembled. Complete replacement is required .

4 . Stop the fuel pump .

Ja

Connect the measuring tool (contains individual measuring glasses).

Measuring too I (9995014) hoses must be extended to prevent crimps.

54 Group 24

Fuel system

1 19 82 0

\



J9

Check injector deviation (test only in case of obvious engine malfunctionl.

Note: To obtain correct reading , all hoses should be empty or full at start of test.

With fuel pump running , lift the air flow sensor plate halfway. Hold it there until one of the meas uring glasses has been filled to 100 cm '. Read the other measuring glasses. Maximum deviation

20 % .

In

case of malfunction:

If injector deviation exceeds 20

%, repeat the test to confirm .

If test results are confirmed:

Swap two injector hoses at the distributor (exchange hoses of one incorrect and one correct opera ting injectorl and repeat the test.

If same injector persists faulty , injector or injector fuel supply line is defective. See "Testing and

Cleaning Injectors " in Service Manual TP 11121

(821 Flor TP 11122 (B27FI.

If fault changes to the other injector , the fuel dis tributor is defective.

1 19822

J10

Service the fuel distributor.

Procedures:

Remo ve fuel di s tributor . Check O-ring .

- Remove plunger. Check for scratches or deposits. Deposits may be removed , u si ng finger nail , NO TOOLS .

Check for seizure by turning plunger and at the same time mo ve the plunger in and out. If se iz ing occurs, replace the fuel distributor assembly.

- In stall O-ring and fuel distributor assembly.

NOTE :

Do not overtighten fuel distributor retaining

screws.

For complete overhaul see "Air-Fuel Controi

Unit " in Service Manual TP 11121 (B21 Flor

TP 11122 ( B27FI .

1 08970

Group 24

Fuel system

55

CI System , F au lt Tr acing

ca check -

CO emissions check

821 F NOT equipped with oxygen sensor feedback system

Kl

Adjust

id le speed Itemporary settingI

Connect in s truments for mea s uring engine rpm

and ca .

Start engine .

NaTE.

En gine should be at normaloperating temp e ra ture.

Adjust idle speed as follows

:

1'9822

900 rpm

821 F Manual

800 rpm

821 FAutomatic

K2

Check

CD reading before catalytic converter

Attach ca gauge at fitting on header pipe just before catalytic converter.

Check ca .

If necessary adjust ca to 1 .

0 %

±

0.3

%.

NaTE :

Engine should b e at normaloperating tempera tu r e.

K3

Check CD reading

af ter

catalytic converter

ca reading shou ld be

~ .

5

%.

NaTE :

If engine is not at operating temperature , this r ead ing connot be obtained .

Set

id le speed (final settingI 900 rpm.

56

Grou p 24

Fuel system

\

CI System F ault Tr aci n g

CO

check-

B27F NOT equipped with oxygen sensor feedback system

5102

; '

I

L1

Adjust idle speed

Connect instruments for m easuring engine rpm and ca.

Start engine.

NaTE:

Engin e s hould be at normaloperating temperature .

Adjust idle speed .

900 rpm

12 6 442

'1797 9

Check CD

L 2

Set va

l ve

to position 2 (center position) .

In t hi s position ex h aust gases are admitted from both engine banks = total reading. ca should be 1.

0

±

0.3 % (0 .

7-1 .

3 %).

Na TE:

When reading , the plug in the ca adjustment hole

(on top of fuel distributor) must be insta ll ed , o r the hole blocked.

From now on , air filter and hoses must be attached, otherwise emissions will be affected.

Adjust CD

L3

Valve in position 2.

Remove

p lug and copper was h er for ca adjustment. U se inhex wrench 5102 to adjust ca.

En gine id l e rpm should be 900.

NaTE :

Af r eac h adjustment, w r ench 5102 must be r e -

m

oved and the hole covered to p r event a lean mixture w hile the ca reading is made.

Counterclockwise adjustment r educes ca, clock wise adjustment increases ca.

Reinstall plug and copper washer.

L4

Check CD balance, left cylinder bank

.

Set

va l

ve to position 1 (toward l e f t cylinder bank) and read ca.

It shou ld be 1.0 ± 0.3

% f o r left bank.

NaTE:

E xcessive HC read i ng might indicate misfiring.

Group

24

Fu el system

57


- ca

check-

L5

Check CD balance, right cylinder bank

Set valve to position 3 (toward right cylinder bank) and read ca.

It should be 1.0

±

0.3

% for right bank.

------=:

N O T E:

Excessive HC reading might indicate misfiring.

i,

-,

11 8816

Right bank

Left bank

"882 1

Setting CD balance

L6

Air adjusting screw (3) permits a certain quantity of air to by pass the throttle va lve at id le. This air quantity is split between the cylinder banks and is balanced by screws (1) and (2). Screw

(1) for right cylinder bank and screw (2) for left cylinder bank.

A decrease in air flow by screw (2) will mean an increase in air flow to screw (1) and vice versa .

If

the ca balance reading is incorrect, adjust by turning one screw up or the other down. ca reading should be equal for both banks and correct for the total system.

NaTE: left side intake manifold goes to right bank, and right side to left bank.

------------==--------------Exarnples-----------------------------

L6a

Exarnple 1 : CD lower on left cylinder bank

NaTE:

Lett side intake manifold goes to right bank, and right side goes to left bank.

Valve in position 3 (toward right bank).

Adjust screws (1) up or (2) down until correct reading of 1.0

±

0.3

% is obtained.

Idle speed 900 rpm.

, 1B820

L6b

Check CD balance

Turn valve to position 1 (toward left bank) and check that same ca readings are obtained for left and right banks.

1 1 8817

58

Group 24

Fuel system

,


- ca check -

L6c

Example 2 : ca higher on left bank

Valve in position 3 (toward right bank).

Adjust screw (1) down or screw (2) up until correct reading of 1.0

±

0.3% is obtained.

Idle speed 900 rpm.

1 18820

L6d

Check ca balance

T urn valve to position 1 (toward left bank) and check that same CO readings are obtained for left and right banks , total system must have correct reading with valve in position 2, center position.

'188 17

L7

Make final ca adjustment

Val ve in position 2 (for total CD).

Adjust CD to 1.0

±

0.3 % .

.

Engine speed 900 rpm.

..

118818

Group

24

Fuel system

59


- ca check-

B21 F equipped with oxygen sensor feedback system

MI

Disconnect sensor wire

60

Group 24

Fuel system

M2

Attach

ca

meter

Attach at fitting before catalytic converter on ex haust pipe.

119811

Adjust idle (temporary setting)

900 rpm

821 F with manual transmission.

800 rpm

821 F with automatic tran smission.

M3

I


- CO

check-

M4

Check

CD

If necessary adjust to :

2.0

+0.5%

=

-1

.

0%

1

.

0-2.5

%

Reconnect sensor wire

Read CD meter. CD shou ld drop below 1 %.

M5

M6

Set id le speed (final settingI

900 rpm

'1 9811

M7

Stop engine

Di sconnect instruments and CD gauge.

CAUTION:

Connecting nipples for CD gauge are VERY HOT.

Reinstall exhaust pipe plugs.

Group

24

Fuel system

61

CI System, F au lt Tracing

- CO

check-

B27F equipped with oxygen sensor feedback system

NI

Disconnect sensor wire

12 44 3 9

N2

Adjust idle speed

Connect instruments for measuring engine rpm and ca.

Start engine.

NaTE:

Engine shou ld be at normaloperating tempera ture.

Adjust idle speed.

900 rpm

1 26 4 42

N3

Check CD

Set valve to position 2 (center position).

In this position exhaust gases are admitted from both engines banks = total reading . ca should be 1.0

±

0.3 % (0.

7-1.3 %).

NaTE :

When reading, the plug in the ca adjustment hole

(on top of fuel distributor) must be installed , or the hole blocked.

From now on, air filter and hoses must be at tached, otherwise emissions will be affected .

' 17 97 9

62 Group 24

Fuel system

5102

iJ

I

Right bank

Left bank


CO

check-

, ,7 4 77

N4

Adjust

ca

Valve in position 2 .

Remove plug and copper washer from CO adjustment. Use inhex wrench 5 102 to adjust CO .

Engine id le rpm should be 900.

NOTE:

Af adjustment , wrench 5102 must be removed and the hole covered to prevent a lean mixture while the CO reading is made.

Counterclockwise adjustment reduces CO, clockwise adjustment increases CO.

Re-install plug and copper washer.

N5

Check

ca

balance, lett cylinder bank

Set valve to position 1 (toward left cylinder bank) and read CO.

It should be 1 .

0

±

0 .

3

% for left bank .

NOTE:

E x cessive HC reading might indicate misfiring.

1 18 817

N6

Check

ca

balance, right cylinder bank

Set valve to position 3 (toward right cylinder bank) and read CO .

It should be 1 .

0

±

0 .

3

% for right bank .

NOTE:

Excessive HC reading might indicate misfiring.

1 1 8 8 21

Setting

ca

balance

N7

Air adjusting screw (3) permits a certain quantity of air to bypass the throttle valve at idle . This air quantity is split between the cylinder banks and is balanced by screws ( 1) and (2) . Screw ( 1 right cylinder bank and screw (2) for left cylinder bank .

A de c rease in air flow by screw (2) will mean an in c rease in air flow to screw (1) and vi c e versa. If the CO balance reading is incorrect, adjust by turning one screw up or the other down.

CO reading should be equal for bot h banks and correct for the total system.

NOTE: left side intake manifold goes to right bank and right side to left bank .

Group

24

Fuel system

63

CI System, Fault Tr acing

- CO

check-

- - - - - - --= :::- - - - - - - E xa mple s

- - - - - - - - - - - - - - - -

Nl a

Example 1: bank. ca lower on left cylinder

NaTE:

Left side intake manifold goes to right bank , and right side goes to left bank.

Va l ve in position 3 (toward right bank).

Adjust screws (1) up or (2) down until correct reading of 1.0

±

0.3

% is obtained.

Idle speed 900 rpm .

118820

Nlb


T urn valve to position 1 (toward left bank) and c heck that same ca readings are obtained for left and right banks.

"8817

Nlc

Example 2: ca higher on left bank

Valve in position 3 (toward right bank) .

Adjust screw (1) down or screw (2) up until correct reading of 1.0

±

0.3 % is obtained.

Idle speed 900 rpm .

Nld


Turn va l ve to position 1 (toward left bank) and check that same ca readings are obtained for left and right banks, total system must have correct reading with va lve in position 2, center position.

118817

- - - - - - - - - - - - - - - - E n d o f e x a m p k s - - - - - - - - - - - - - - - -

64 Group 24

Fuel sys tem

CI Sy s tem , Fault Tra ci ng

ca c heck-

N8

Make final ca adjustment

Valve in position 2 (fo r total COl.

Adjust ca to

1.0

±

0.3 % .

Engine speed 900 rpm .

Stop engine

N9

Reconnect sensor wire

Read ca meter. ca s h o uld drop below 1

%.

NIO

Set idle speed (final setting)

900 rpm

126 44 2

NII

Stop engine

Di sco nn ec t instruments and ca gauge.

CAUTION:

Connecting nipples for ca gauge are VERY HOT .

Rein stall exhaust pipe plugs.

118819

Group

24

Fuel system

65


- Lambda sond-

Additional Information

Oxygen Sensor Feedback System

A malfunction of this system may appear as:

- Oifficult starting with engine at normal operating temperature

- Erratic idle

- Poor engine performance , especially in lower speed ranges

- Poor gas mileage

The following procedure can be used as a simple check of the oxygen sensor feedback system.

123291

01

Set ignition switch to ON

Do not start engine.

NOTE:

This check must be made in an area free from noise which could prevent hearing the buzzing sound from the frequency valve.

02

Operate the fuel pump

1976-1977:


1978:

Install test relay fuel pump.

5170 to start the

1 23 7 92

03

Check for buzzing sound from frequency valve

If no buzzing sound occurs, or if there is strong reason to believe that this system is defective, proceed to the following steps.

If buzzing sound occurs, disconnect test relay

(1978 modeis) or install connector previously removed (1976-1977 models).

1 20 988

66 Group 24

Fuel system

120962


- Lambda sond -

04

Connect dwell meter

Use dwell meter to check duty cycle (ratio open / close) of frequency valve .

NOTE: The dwell meter should be of high quaiity with a scale reading of at least 70 " .

Example: Sun instruments, recent models.

Connect the meter between the pick -up connector and ground (see illustration).

05

Disconnect sensor

Remove wire to Lambda-sond sensor in exhaust manifoid.

1 20963

06

Check dwell meter reading (duty cycle)

Set meter as you would for 4 cylinder engine.

Reading should be:

821 F: 49-59"

827F: 40-50 " at engine temperature of

+

15 " C (60 " F) or above.

7 1-8 1" - at temperatures below

+

15 " C

(60 " F).

A thermal switch senses the cool an t temperature and closes at temperatures below

+

15 " C . (This provides for the change in frequency valve duty cycle).

120964

If the reac!ings are not correct , troubleshoot the oxygen sensor feedback system using the associated fault tracing manual.

Group 24

Fuel system

67


Wiring Diagram , 240/1976-

el Fuellnjection System

240/1976

~~,"Å'Ut!:14 ~

..

."

\

~

"Z"I!!_~

Starter

18

rr===--.J

Main motor re\ay i

The rm a\ time switch

Air If uel co n tral unil

Gald start injector

Starting engine

Engine running

ck/b

Fuse No, 5

Instruments

Turn signals

Indicator lights

Relay, fuel injection system

Fuse No, 7

Clock

Fuel pump

Engine stalled (ignition on, but engine not running)

68

Auxiliary air valve

6lue uellokJ

Connector at ignition lock

el Fuel Injection System

240/1976

el System, Fault T

Wiring Diagram, 240 / 1976 -

~'----ump re ay .

Fuel pump

Starter motor

-----

Fuse box eold start injector Controi pressure regulator

Air / fuel controi unit

69

el System , Fault rracing

Wiring Diagram , 240 / 1977-


240/1977

Fue l fe ed pump

blaclcf8 hJacJ.:.J6

Fuse

No

.

5

Instruments

T urn signals

In di c ator lights

Relay , fuel injection sy s tem

(Seat belt warning)

Fuse

No. 7

Clock

Fuel pump

Cold start injector

T h e rma\ time switch

Air f ue l con tr oi uni !

Starting engine

Engine running Engine stalled (ignition on, but engine not running)

70

e l System, F a ul t Tr acing

- Wiring D iag r a m , 240 /

1 977 -

el Fuel Injection- System 240/ 1977

Fuel f eed pump

bl

~'J1

/,lue hlu.e

Connector

-------

'fii'_._--_._,_._.I

F ue l p ump

blue:y elZolJ

Con n ector at ignition lock

Auxilia r y air va l ve

F use box

I

\

Sta r te r motor

&lue -

JlIlllow

Co l d sta r t injec t or

------

Main relay. P ump R e l ay.

I..

omr ' ml pressure regulator

h/ack.

Air / fu el co n troi u n it

71

el S ys t em, F a ult Tra c ing

- Wiri n g D ia gr a m , 24 01

1978 -

el Fuellnjection System

240/1978

F us e bOJ(

Cont r o i pressure lO

Slarter mo t or

T hermal li me switch

:f

~

.6-:;'0&1-"1

~

1S i

3I b

El e ctronic fua l pum p r e l a y

CoJd start inj e c lor

Aux il ia r y a i r ... sl v e

Ignilion coil

IS 31b

Jt--t?1F

~~~u"", .q: = J

Igni t ion disl r i b utor

Fuse No. 5

In s trume n t s

T urn s ig n al s

Ind ica t o r l i ght s

R e la y , f ue l i n jec t io n sy st e m

Fuse No

.

7

F u e l p u m p , fu e l fee d p u mp

Starting engine Engine running Engine stalled (ignition on, but engine not running)

72


240/1978


- Wiring Diagram , 240 /

1978 -

,hlue-y e llolJ

•

Thermal time s""itch" feed pump

Ignition coil

Starter motor

Fuel pump

air

i i

Ca Id start injector

Controi pressure regulator.

Fuse bo x

73


- Wiring Diagram , 260 / 1976-


260/1976

ålue14

" . . . 1

Fuse box

Con tr ei pressu r e regula t or

Fuse No

,

5

Instruments

T urn signals

Indicator lights

Relay , fuel injection system

(S e at belt warning l

Fuse No, 7

Clock

Fuel pump

S t arter moto r

Therma l time switch

Ce l d star t inJecto r

Starting engine

Ai r fue l contral uni!

Engine running

Auxil i ary ai r valve

Engine stalled (ignition on

,

but engine not runningl

74



el Fuellnjection System 260/1976

Cold start injector Main relav.

Pump relav.

Auxiliarv air valve


Starter motor

r--

,....-----........,

...

-._-------

Fuse box

Contral pressure regulator.

Thermal time switch

Air / fuel controi unit

75



el Fuellnjection

System

260/1977

,.

Fu se bo x

Co nt r ol p rf l'ss u r e regu l ato r

lue/4 ~

'\j

~

~

Starter m o tor

'"

i

Main re l ay

~

...

l •

Fuel feed pump

Q c..f/ 8

bIQcA:./~

Fuse No. 5

Instruments

Turn signals

Indicator lights

Relay, fuel injection system

(Seat belt warning)

Fuse No. 7

Clock

Fuel pump

.w

\

Fuse

C o l d s lart ini ector

Therma \ time switch

Ai r fuel contra! uni!

Starting engine Engine running Engine stalled (ignition on , but engine not runningl

76

el

System , Fault Tracing

- Wiring Diagram , 26011977-

el Fuellnjection System 260/ 1977

Cold start injector

Main relay. Pump relay .

Fuse

Starter motor

Fuel pump

Fuel feed pump

Connector at ignition lock time switch Air / fuel

77


- Wiring Diagram, 260 / 1978-


260/1978

t:::)jb2ue14

Controi pressure regulator

Fuel pump

Fuse No. 5

Instruments

T urn signals

Indicator lights

Relay. fuel injection system

Electrically operated side

mirro rs

1l ==;ilF#l~ ~1 '""

'Jiblaek 18

Fusa

Starter motor

.'il_

~

Thermal t i m e switch

Cold start in Jector

I gnition

1L=

=,j

"

t:~;;,,~=d;J

di slri bu tc r

"

I gnition elec t ron ic module

Starting engine Engine running Engine stalled (ignition

on,

but engine not running)

9 9

~

78

el System , Fault T racing

- Wiring Diagram, 260 / 1978 -

Cold start injector

Electronic fuel pump relay

Starter motor

Fus e

..

~::~blue

.:>

.

~

hlue-YellolJ


Fuel feed pump

Ignition coil l l

pre ss ur e

regulator.

Fuse bo x

Auxiliary air valve

Thermal time switch

Ignition distributer

79

~

I

•

•

VOLVO SUPPORTS VOLUNTARY

MECHANIC CERTIFICATION

BY THE N.I

.

A .

S .

E .

( U .

SA O nly )

Volvo 240 1976-1978, 260 1976-1978 Fuel Injection System Fault tracing

Assistant Bot

Fault tracing el Fuellnjection System

Section Group

el Fuel Injection

System

Contents

Introduction ..

......

....

.

.

....

Symptoms:

Fault Analysis:

Fuel Supply:

Electrical Supply:

CO Emissions Check:

Additional information:

Wiring Diagrams:

1

Introduction

Mechanical

Electrical

Emission Controls

Specifications

Common symptoms

Complex symptoms

Overhaul

Additional information

3-step information

Specifications / Description

Fuel feed pump

Fuel pump and accumulator

",JUU

Fuel filter

--

----~.,~,,

oo

":~

,

Relays

t-

-f--c:

B27F

B 27 F

±

±

Special Tools

el System, 821 F - Exploded

r-~~------~\

el System, 827F - ExplodedView

Quick reference fault tracing guide

Symptom - cold engine difficult to start or no start

Battery weak

Weak or no ignition spark

Air intake system blocked

Fuel supply

Fuel pump operation

Air induction system

Main relay operation

Cold start injector

Air flow sensor plate

Continued next page

Injector operation

Symptom - cold engine difficult to start or no start

eontinued from previous page

Malfunction in system other than el fuel

Ignition

eompression

mission

controi

Other possible trouble areas ...

Vacuum leaks

Extreme cold

el fuel system malfunction

Symptom - warm engine difficult to start

Symptom - cold

& warm engine difficult to start

Symptom - erratic running engine / cold or during warmup