Content .. 5 6 7 8 ..

Opel Corsa / Vauxhall. Manual - part 7

Fuel and exhaust systems - fuel-injected models 4B•7

11.3a Detach the wiring connector from

11.3b Throttle valve potentiometer removal

11.6a Disconnect the wiring connector . . .

the throttle valve potentiometer

11.6b . . . undo the retaining screw . . .

11.6c . . . and remove the injector

11.11a Detach the wiring connector . . .

12 Refit in the reverse order of removal. To

Pressure regulator

described in Section 6.

avoid damaging the injector housing as the

17 Undo the four retaining screws and

16 Prior to removal of the regulator unit, a

motor unit is refitted, press the cone in against

new diaphragm must be obtained as this must

carefully withdraw the regulator unit cover,

its stop and check that the top of the cone to

spring and diaphragm (see illustrations).

be renewed whenever the cover is removed.

the mating flange face is within 28 mm (see

Release the pressure in the fuel system as

18 Refit in the reverse order of removal.

illustration).

Throttle body/injector housing unit

13 Disconnect the wiring connectors from

the throttle body/injector housing.

14 Disconnect the operating rod, then

unscrew and remove the two retaining nuts

from the studs and carefully lift the throttle

body/injector housing from the inlet manifold.

Remove the gasket and clean the mating

surfaces.

15 Refit in the reverse order of removal, but

be sure to fit a new gasket between the

manifold and the throttle body/injector unit.

Tighten the retaining nuts to the specified

11.11b . . . undo the retaining screws . . .

11.11c . . . and remove the idle air stepper

torque setting.

motor

11.12 Idle air stepper motor cone tip-to-

11.17a Undo the retaining screws . . .

11.17b . . . and remove the pressure

flange distance should be as specified

regulator cover, spring and diaphragm

4B•8 Fuel and exhaust systems - fuel-injected models

Ensure that the new diaphragm and its

seatings are clean. Note that no adjustment to

the regulator unit is necessary (or possible).

Inlet manifold pressure sensor

19 This unit is located on the engine side of

the bulkhead. Disconnect the wiring

connector and the vacuum hose, then detach

and remove the unit from the bulkhead.

20 Refit in the reverse order of removal,

ensuring that the vacuum hose and wiring

plug are securely reconnected. Position the

vacuum hose so that it progressively slopes

down between the inlet manifold pressure

12.4 Tightening a throttle valve switch

12.6 Slackening a fuel rail hose clamp

sensor and the throttle housing.

screw

Control unit

Oxygen sensor

withdraw the fuel rail from the injectors (see

illustration). Catch as much fuel as possible.

21 Detach and remove the trim panel from

33 Refer to Section 12, paragraphs 93 to 96.

7 Disconnect the wiring plugs from the

the right-hand footwell to gain access to the

injectors.

control unit.

12 Multi-point fuel injection

8 Unscrew the retaining bolts

(two per

22 Disconnect the wiring multi-plug

system components (1.8 and

injector) and withdraw the injectors from their

connectors, undo the retaining screw then

2.0 litre models) - removal and

holders, being careful not to damage the

release and remove the control unit.

refitting

needle valves (see illustration).

23 The control unit also contains a

9 Refit in the reverse order to removal; renew

programmable memory (PROM) unit in which

the injector sealing rings if their condition is at

the engine/vehicle data and calibration are

1 Disconnect the battery and proceed as

all doubtful.

stored. If this unit is known to be faulty it can

described under the relevant sub-heading.

Later (1990 on) models

be removed from the control unit and

1.8 litre models

10 Refer to paragraphs 5 to 9, noting that the

renewed separately. If the control unit is at

fuel rail is retained by bolts and the injectors

fault, the PROM unit should be removed from

Throttle valve switch

are secured to the fuel rail by clips.

it, the control unit alone renewed and the

2 Disconnect the wiring plug from the switch.

Airflow meter

original PROM unit fitted to the new control

3 Remove the two mounting screws and pull

unit.

11 The airflow meter is located between the

the switch off the throttle valve spindle.

24 To separate the PROM from the control

air cleaner and the throttle valve housing.

4 Refit in the reverse order to removal,

unit, detach and withdraw the cover from the

12 Disconnect the wiring harness plug from

adjusting the switch as follows. Release the

end of the control unit, then press back the

the airflow meter. Release the securing band

switch mounting screws and rotate the switch

retaining clips, unplug and withdraw the

and remove the rubber trunking

(see

in an anti-clockwise direction until resistance

PROM unit from the control unit. When

illustration).

is felt. Tighten the screws (see illustration).

13 Release the spring clips and remove the

removed, no attempt must be made to open

Have an assistant open the throttle valve

airflow meter with the upper part of the air

and/or tamper with the PROM unit. Ensure

slightly by depressing the accelerator pedal. A

cleaner housing.

that its plug contacts are clean and in good

click should be heard from the switch as the

14 Unbolt the airflow meter from the air

condition.

throttle opens; another click should be heard

cleaner housing (see illustration).

25 If renewing the control unit it is important

when the pedal is released..

15 Check the meter flap for free movement,

that the part number/code sticker label is

Fuel injectors

without any jerkiness. If necessary, clean

transferred to the new unit.

away any dirt in the area of the flap using a

26 Refit in the reverse order of the removal

Early (pre 1990) models

clean lint-free rag.

procedure. On completion, switch on the

5 Make sure that the engine is cool, and that

16 Refit in the reverse order to removal.

ignition and check for satisfactory operation.

all sources of external ignition (eg pilot lights)

Control unit

have been extinguished. Disconnect the

Coolant temperature sensor

battery earth lead.

Early (pre 1990) models

27 Partially drain the cooling system to allow

6 Bearing in mind the information given in

17 The control unit is located at the side of

the temperature sensor to be removed

Section

6, release the hose clamps and

the front footwell, on the passenger side.

without excessive coolant loss (Chapter 1).

28 Disconnect the multi-plug from the

temperature sensor, then unscrew the sensor.

Note the position of the sealing ring.

29 Refitting is a reversal of the removal

procedure, using a new sealing ring and

tightening the sensor securely.

Road speed sensor

30 Unclip the road speed sensor multi-plug,

located near the base of the speedometer

cable, and disconnect it. Unscrew and detach

the speedometer cable from the sensor.

31 Unscrew the road speed sensor from its

gearbox location and remove it.

12.8 Undoing a fuel injector retaining bolt

12.12 Disconnecting the airflow meter

32 Refitting is the reverse to removal.

trunking

Fuel and exhaust systems - fuel-injected models 4B•9

12.14 Airflow meter securing bolts

12.36a Removing the control relay and

12.36b Unplugging the control relay

(arrowed)

bracket

18 Remove the footwell trim panel.

temperature gauge sensor, it is known as

37 Refit in the reverse order to removal.

19 Make sure that the ignition is switched off,

temperature sensor ll.

Fuel pressure regulator

then release the multi-plug spring clip and

26 Partially drain the cooling system - about

38 The fuel pressure regulator is located

disconnect the multi-plug.

3 litres should be sufficient.

between injectors 3 and 4 (see illustration).

20 Remove the three securing screws and

27 Disconnect the electrical lead and

39 Disconnect the battery earth lead and

withdraw the control unit.

unscrew the sensor.

take appropriate fire precautions.

21 Refit in the reverse order to removal, but

28 Refit in the reverse order to removal. Use

40 Clamp the fuel hoses to minimise fuel

make sure that the ignition is switched off

a little sealant on the sensor threads, and refill

loss, using self-locking grips with suitably

before reconnecting the multi-plug.

the cooling system on completion.

protected jaws.

Later (1990 on) models

Auxiliary air valve

41 Disconnect the fuel and vacuum hoses

22 Remove the airflow meter as described

29 The auxiliary air valve is bolted to the side

form the pressure regulator and remove it. Be

earlier.

of the camshaft housing.

prepared for fuel spillage.

23 Remove the four screws which secure the

30 Disconnect the wiring plug from the valve.

42 Refit in the reverse order to removal.

cover to the top of the airflow meter (these

31 Release the hose clips and disconnect the

may be hidden by blanking plugs). Remove

2.0 litre models

air hoses from the valve.

the cover and insert, then the control unit.

32 Unbolt and remove the valve.

43 Refer to the information given earlier for

24 Refitting is the reverse of removal.

33 The function of the valve may be checked

the 1.8 litre models, information for additional

Coolant temperature sensor

by looking through the hose connecting

components is as follows

25 The coolant temperature sensor for the

stubs. A clear passage should exist between

Idle speed adjuster

fuel injection system is located near the

the stubs when the valve is cold. As the valve

44 Note the routing and positioning of the air

alternator. Because it is additional to the

is heated

(achieved by connecting its

hoses, then disconnect the multi-plug and the

terminals to a 12 volt battery) the regulator

air hoses from the idle speed adjuster (see

disc should move round and block the hole.

illustrations). On the 16-valve engine the

34 Refit in the reverse order to removal, using

adjuster is located below the inlet manifold;

new hose clips if necessary. An air leak on the

access is not good but is easier from below.

intake side of the valve will raise the idle speed.

45 Refitting is the reverse of the removal

Control relay

procedure.

35 The control relay is located on the front

Control unit

suspension strut turret. Unplugging the relay

46 The control unit is located behind the side

disables the fuel pump - this is necessary

trim panel in the driver’s footwell. To remove

when performing a compression test.

the trim panel, first remove the front two

36 Slacken the securing bolt, remove the

screws from the driver’s ‘kick plate’ and peel

relay and its bracket from the turret, and

back the door surround strip in the area next

withdraw the relay from the plug

(see

to the side trim panel (see illustrations).

12.38 Fuel pressure regulator

illustrations).

12.44a Disconnect the idle speed adjuster

12.44b . . . and the air hoses (arrowed)

12.46a Remove the kick plate screws . . .

multi-plug . . .

4B•10 Fuel and exhaust systems - fuel-injected models

12.46b . . . and peel back the door

12.47 Prise out the clips to release the trim

12.48 Motronic control unit location

surround strip

panel

47 Open the access panel in the side trim.

injectors to the fuel rail by prising them out.

63 Disconnect the multi-plugs from the air

Prise out the plastic retaining clips and

55 Disconnect the brake servo hose from the

mass meter and from the throttle valve switch.

withdraw the side trim panel

(see

throttle body housing.

64 Unbolt the throttle cable bracket and

illustration).

56 Unbolt the fuel supply hose bracket.

move it aside.

48 Remove the retaining screws to release

57 Carefully lift the fuel rail away from the

65 Remove the nuts securing the earth straps

the control unit (see illustration). Release the

manifold and pull out the injectors.

at each end of the fuel rail (see illustration).

multi-plug catch and disconnect the

58 Refitting is the reverse of the removal

66 The injector multi-plugs must now be

multi-plug. Handle the control unit with care if

procedure. If the old injectors are being

disconnected. Each plug is secured by a

it is to be re-used.

refitted, use new sealing rings.

spring clip, which must be levered out with a

49 Refitting is the reverse of the removal

small screwdriver or long-nosed pliers. With

Fuel injectors - Motronic M2.5

procedure.

all the multi-plugs released, cut or undo cable

59 Remove the pre-volume chamber as

Inductive pulse sensor

ties as necessary and move the wiring rail

described earlier.

forwards so that it rests on the camshaft

50 Refer to Chapter 5.

60 Bearing in mind the information in Section

cover (see illustrations).

6, clean around the unions on the fuel rail, then

Fuel injectors - Motronic ML4.1 and

67 Remove the two bolts which secure the

disconnect the supply and return hoses from it

M1.5

fuel rail to the inlet manifold.

(see illustration). Be prepared for fuel spillage.

51 Remove the idle speed adjuster.

68 Pull the rail and injectors away from the

61 Disconnect the two crankcase ventilation

52 Disconnect the wiring plugs from the fuel

manifold.

hoses from the camshaft cover. To improve

injectors.

access, remove the larger of the two hoses

69 Individual injectors may now be removed

53 Unbolt the fuel rail from the inlet manifold,

completely.

from the rail by removing their retaining clips

bearing in mind the information in Section 6.

62 Disconnect the vacuum hose from the fuel

and pulling them from the rail

(see

54 Remove the clips which secure the

pressure regulator.

illustrations).

12.60 Disconnecting the fuel supply line

12.65 One of the earth straps on the fuel

12.66a Removing the spring clip from an

from the fuel rail

rail

injector multi-plug

12.66b Lifting the wiring rail off the

12.69a Remove the retaining clip

12.69b . . . and pull out the injector

injectors

Fuel and exhaust systems - fuel-injected models 4B•11

12.73 Disconnecting the fuel return line

12.74 Disconnecting the vacuum hose

12.77 Removing a pre-volume chamber

from the fuel pressure regulator

screw

70 Refitting is the reverse of the removal

75 Remove the four Torx screws which

83 Refitting is the reverse of the removal

procedure. If the old injectors are being

secure the pressure regulator to the fuel rail. A

procedure. Adjust the switch before tightening

refitted, use new sealing rings.

small E6 Torx spanner will be needed for

the screws as described in paragraph 4 of this

access to the screws. If this is not available

Section.

Throttle valve potentiometer -

the fuel rail will have to be removed so that the

Motronic M1.5

Air mass meter - Motronic M2.5

screws can be undone with a socket or (at a

71 The throttle valve potentiometer is

pinch) self-locking pliers. With the screws

84 Disconnect the multi-plug from the air

removed and refitted in the same way as the

removed, the pressure regulator can be

mass meter (see illustration).

throttle valve switch (which it replaces) on

removed from the rail.

85 Release the hose clips from each end of the

earlier models. There is no need for

76 Refitting is the reverse the removal.

meter and remove it. Do not drop it, it is fragile.

adjustment.

Pre-volume chamber - Motronic M2.5

86 Refitting is the reverse of the removal

procedure.

Fuel pressure regulator - Motronic

77 Remove the four Allen screws which

M1.5 and 2.5

Coolant temperature sensor -

secure the pre-volume chamber to the throttle

Motronic M2.5

72 On Motronic M2.5 systems, remove the

housing (see illustration). On some models

pre-volume chamber.

there is a fifth screw to the left which must

87 Partially drain the cooling system at the

73 Bearing in mind the information in Section 6,

also be removed.

radiator bottom hose to bring the coolant level

disconnect the fuel return union from the

78 Release the hose clip which secures the

below the level of the thermostat housing.

pressure regulator

(see illustration). Be

air mass meter to the pre-volume chamber.

88 Disconnect the multi-plug from the sensor

prepared for fuel spillage.

79 Lift the pre-volume chamber slightly and

on the thermostat housing. The Motronic

74 Disconnect the vacuum hose from the

disconnect the idle speed adjuster hose from

sensor is the larger of the two the smaller one

regulator (see illustration).

the left-hand end (see illustration). Remove

feeds the temperature gauge. Unscrew the

the pre-volume chamber.

sensor and remove it.

80 Refitting is the reverse of the removal

89 Refitting is the reverse of the removal

procedure, but note that it is important that

procedure, noting the following points:

the ring which seals the throttle body to the

a) Use a new sealing ring on the sensor, and

pre-volume chamber is not displaced during

apply a little sealant to its threads.

fitting. Air leaks at this point will weaken the

b) Refill the cooling system as described in

mixture and dirt may enter. Secure the ring to

Chapter 1.

the chamber if necessary with a few dabs of

Knock sensor - Motronic M2.5

sealant (see illustration).

90 The knock sensor is on the rear of the

Throttle valve switch - Motronic M 2.5

cylinder block. Unless the inlet manifold has

81 Remove the pre-volume chamber and the

been removed, access is easiest from below.

air mass meter.

91 Disconnect the multi-plug (coloured red or

82 Disconnect the multi-plug from the switch

orange) from the knock sensor. Remove the

(see illustration). Remove the two screws

securing screw and the sensor

(see

12.79 Idle speed adjuster hose attachment

and withdraw the switch.

illustration).

to pre-volume chamber

12.80 Pre-volume chamber sealing ring

12.82 Disconnecting the throttle valve

12.84 Disconnecting the multi-plug from

switch multi-plug

the air mass meter

4B•12 Fuel and exhaust systems - fuel-injected models

12.91 Knock sensor multi-plug (arrowed)

12.94 Disconnecting the oxygen sensor

12.95 Removing the oxygen sensor

seen from below

multi-plug

12.98a Canister clamp nut (arrowed)

12.98b Disconnecting a hose from the

12.100 Disconnecting the vent valve

canister

multi-plug

92 Refitting is the reverse of the removal

hoses from it and remove it

(see

e) Auxiliary air valve (see illustration).

procedure, but make sure that the sensor and

illustrations). Treat the canister with the

f) Cam cover earth tags.

its seat are perfectly clean and that the sensor

same precautions as would apply to a fuel

4 Disconnect the distributor vacuum hose

is secured firmly. Failure to observe these

tank - it may be full of vapour.

from the throttle valve housing

(see

points could lead to damage to the engine,

99 Refitting is the reverse of the removal

illustration).

because a poorly mounted sensor will not

procedure.

5 Depressurise the cooling system by

pick up knocking

(pinking) and the

unscrewing the expansion tank cap, taking

Vent valve - 16-valve models with a

appropriate ignition correction will not be

precautions against scalding if the system is

catalytic converter

applied.

hot. Disconnect and plug the coolant hoses

100 Disconnect the multi-plug and the hoses

from the throttle valve housing.

Oxygen sensor - models with a

from the vent valve (see illustration). Unbolt

6 Disconnect the air inlet duct from the

catalytic converter

the valve bracket and remove the valve and

housing.

93 Bring the engine to operating

bracket.

7 Disconnect the brake servo and crankcase

temperature, then switch it off and disconnect

101 Refitting is the reverse of the removal

ventilation hoses from the housing.

the battery.

procedure.

8 Disconnect and plug the fuel hoses from

94 Disconnect the oxygen sensor multi-plug,

the fuel rail stubs. The hoses are different

which is located near the right-hand

13 Inlet manifold - removal and

sizes and one of them carries a white band for

suspension turret (see illustration). Free the

refitting

identification. Be prepared for fuel spillage.

wiring leading to the sensor.

9 Disconnect the accelerator cable from the

95 Working under the vehicle, unscrew the

throttle levers. The cable inner is secured by a

sensor from the exhaust manifold

(see

Removal

illustration).

96 Refitting is the reverse of the removal

1.4 and 1.6 litre models

procedure. Note that the makers specify the

1 Refer to the information given in Section 11,

use of a special anti-seize compound made of

Chapter 4A, for information on the various

graphite and glass beads. New sensors are

electrical components which must be

provided with their threads already coated

disconnected.

with this compound. When refitting a used

1.8 litre models

sensor, obtain some of the special compound

from a Vauxhall dealer.

2 Disconnect the battery earth lead.

3 Disconnect the injection wiring harness

Carbon canister - 16-valve models

plugs and earth connections as follows:

with a catalytic converter

a) Airflow meter plug.

97 Raise the front of the vehicle and remove

b) Coolant temperature sensor (see

the left-hand roadwheel.

illustration).

13.3a Coolant temperature sensor plug

98 Slacken the canister clamp nut. Release

c) Fuel injectors (see illustration).

(arrowed)

the canister from the clamp, disconnect the

d) Throttle valve switch (see illustration).

Fuel and exhaust systems - fuel-injected models 4B•13

13.3b Disconnecting a fuel injector plug

13.3c Unplugging the throttle valve switch

13.3d Unplugging the auxiliary air valve

lead connector

wire clip, and the outer is retained in its

adjuster strap nut and bolt (see Chapter 1).

24 Bearing in mind the information given in

bracket by an E-clip (see illustration).

17 Disconnect the throttle cable from the

Section 6, disconnect the fuel supply and

10 Unscrew the nuts which secure the inlet

throttle housing. Pull the cable out of the

return unions from the fuel rail. Be prepared

manifold to the cylinder head. The lower nuts

retainer and move it aside (see illustration).

for fuel spillage.

are different to reach: a small socket or ring

18 Remove the 9 nuts which secure the

25 Release the fuel supply hose bracket from

spanner will be needed.

manifold to the cylinder head. These are all

the throttle housing.

11 Lift away the manifold and recover the

stiff and some are not easily accessible; a

26 Release the cable tie which secures the

gasket (see illustrations).

socket with a “wobble drive” or universal joint

coolant hoses to the right-hand side of the

will be needed. Once the nuts are removed,

manifold.

2.0 litre 8-valve models

slide the manifold back on its studs to

27 Disconnect the brake servo vacuum hose

12 Refer to the information given above in

improve access to the injector wiring rail.

and the large coolant hose from the base of

paragraphs

2 to

11, noting the hose

19 Disconnect the two breather hoses from

the manifold (see illustrations).

connections shown (see illustration).

the camshaft cover.

28 Unhook the clutch cable from the bracket

2.0 litre 16-valve models

20 Disconnect the injector wiring rail from the

behind the manifold.

13 Disconnect the battery earth (negative)

injectors as described earlier.

29 Disconnect the small coolant hose from

lead.

21 Release the earth straps from each end of

the expansion tank.

14 Drain the cooling system (see Chapter 1).

the fuel rail.

30 Disconnect the air hose which connects

15 Remove the pre-volume chamber, the air

22 If a vent valve is fitted, disconnect the

the idle speed adjuster to the base of the

mass meter and its trunking as described in

multi-plug and the hose from it.

manifold.

Section 12.

23 Disconnect the throttle position switch

31 With the help of an assistant, lift the

16 Remove the alternator drivebelt and the

multi-plug.

manifold to gain access to the idle speed

13.9 Accelerator cable at engine end

13.4 Distributor vacuum hose (A), coolant

13.11a Removing the inlet manifold -

hose (B) and breather (C) on throttle housing

1.8 litre model

13.12 Throttle valve housing - ML4.1

A Hose from idle speed adjuster

B Crankcase ventilation hose

13.11b Inlet manifold showing injectors

C Coolant hose

13.17 Pulling the throttle cable out of the

fuel rail and associated components

D Coolant hose

retainer

4B•14 Fuel and exhaust systems - fuel-injected models

13.27a Disconnect the brake servo

13.27b . . . and the large coolant hose

13.32 Removing the inlet manifold - 2. litre

hose . . .

16-valve model

adjuster and the knock sensor. Disconnect

b) Tighten the manifold nuts to the specified

support bracket (see illustration).

the multiplugs from these components and

torque.

6 Lift away the manifold and recover the

feed the wiring harness back through the

c) Refill and bleed the cooling system as

gasket.

manifold.

described in Chapter 1.

All other models

32 Remove the manifold complete with fuel

7 Refer to Chapter 4A. On models with an

rail and injectors (see illustration). Recover

14 Exhaust manifold - removal

oxygen sensor, disconnect the sensor multi-

the gasket.

and refitting

plug and free the wiring to prevent it being

Refitting

strained whilst the manifold is removed.

33 Refitting is the reverse of the removal

Removal

Refitting

procedure, noting the following points:

8 Refitting is the reverse of the removal

a) Use a new manifold gasket (see

2.0 litre 16-valve models

procedure, using a new manifold gasket (see

illustration).

1 Raise and securely support the front of the

illustration).

vehicle (see “Jacking and Vehicle Support”).

2 Disconnect the battery earth

(negative)

15 Exhaust system - inspection,

lead.

3 Remove the manifold heat shield, which is

removal and refitting

secured by three bolts at the top and two of

the manifold nuts at the bottom

(see

1 Refer to Chapter 4A. On models with an

illustration).

oxygen sensor, it will be necessary to

4 Remove the remaining

10 nuts which

disconnect the sensor multi-plug and free the

secure the manifold.

wiring from its retaining clips before removal.

5 On models with an oxygen sensor,

On refitting ensure the sensor wiring is

disconnect the sensor multiplug (near the

correctly routed and in no danger of

right-hand suspension mounting) and free the

contacting the exhaust system.

wiring leading to the sensor.

13.33 Fitting a new inlet manifold gasket

5 Working under the vehicle, unbolt the

manifold-to-exhaust system flexible joint and

14.3 Removing an exhaust manifold heat

14.5 Manifold-to-exhaust system joint and

14.8 Fitting a new exhaust manifold gasket

shield bolt

bracket

5A•1

Chapter 5 Part A:

Starting and charging systems

Contents

Alternator - removal and fitting

General information and precautions

Alternator - testing and overhaul

Ignition switch - removal and refitting

Alternator drivebelt - removal, refitting and tensioning

Oil level sensor (16-valve models) - removal and refitting

Battery - removal and refitting

Oil pressure warning light switch/gauge sender - removal and

Battery - testing and charging

refitting

Battery check

See Chapter 1

Starter motor - removal and refitting

Charging system - testing

Starter motor - testing and overhaul

Electrical fault finding - general information

Starting system - testing

Electrical system check

See Chapter 1

Degrees of difficulty

Easy, suitable for

Fairly easy, suitable

Fairly difficult,

Difficult, suitable for

Very difficult,

novice with little

for beginner with

suitable for competent

experienced DIY

suitable for expert

experience

some experience

DIY mechanic

mechanic

DIY or professional

Specifications

System type

12V negative earth

Battery

Capacity

36 to 66 Ah (depending on model)

Charge condition:

Poor

12.5 volts

Normal

12.6 volts

Good

12.7 volts

Alternator

Type

Bosch or Delco

Output

45, 55 or 65A (depending on model)

Starter motor

Type

Pre-engaged Bosch or Delco

Torque wrench settings

lbf ft

Alternator mounting bracket bolts*

Alternator pivot and adjustment bolts*

Starter motor mounting bolts*:

1.3 litre models

1.6, 1.8 and 2.0 litre models

*Torque wrench settings for the 1.2 litre models not available

The battery is of the low maintenance or

While some repair procedures are given, the

1 General information and

“maintenance-free” (sealed for life) type and is

usual course of action is to renew the

precautions

charged by the alternator, which is belt-driven

component concerned. The owner whose

from the crankshaft pulley.

interest extends beyond mere component

The starter motor is a pre-engaged type

renewal should obtain a copy of the

General information

incorporating an integral solenoid. On starting,

“Automobile Electrical & Electronic Systems

The engine electrical system consists

the solenoid moves the drive pinion into

Manual”, available from the publishers of this

mainly of the charging and starting systems.

engagement with the flywheel ring gear before

manual.

Because of their engine-related functions,

the starter motor is energised. Once the

It is necessary to take extra care when

these components are covered separately

engine has started, a one-way clutch prevents

working on the electrical system to avoid

from the body electrical devices such as the

the motor armature being driven by the engine

damage to semi-conductor devices (diodes

lights, instruments, etc (which are covered in

until the pinion disengages from the flywheel.

and transistors), and to avoid the risk of

Chapter

12). Refer to Part B or C for

personal injury. In addition to the precautions

information on the ignition system.

Precautions

given in the “Safety first!” section of this

The electrical system is of the

12-volt

Further details of the various systems are

manual, observe the following when working

negative earth type.

given in the relevant Sections of this Chapter.

on the system:

5A•2 Starting and charging systems

Always remove rings, watches, etc before

or deterioration of the internal plates.

Standard and low maintenance

working on the electrical system. Even with

3 If the specific gravity variation is 0.040 or

battery - charging

the battery disconnected, capacitive

more, the battery should be renewed. If the

Note: The following is intended as a guide

discharge could occur if a component’s live

cell variation is satisfactory but the battery is

only. Always refer to the manufacturer’s

terminal is earthed through a metal object.

discharged, it should be charged as

recommendations (often printed on a label

This could cause a shock or nasty burn.

described later in this Section.

attached to the battery) before charging a

Do not reverse the battery connections.

Maintenance-free battery -

battery.

Components such as the alternator, electronic

testing

9 Charge the battery at a rate of 3.5 to 4

control units, or any other components having

amps and continue to charge the battery at

semi-conductor circuitry could be irreparably

4 In cases where a

“sealed for life”

this rate until no further rise in specific gravity

damaged.

maintenance-free battery is fitted, topping-up

is noted over a four hour period.

If the engine is being started using jump

and testing of the electrolyte in each cell is not

10 Alternatively, a trickle charger charging at

leads and a slave battery, connect the

possible. The condition of the battery can

the rate of

1.5 amps can safely be used

batteries positive-to-positive and negative-to-

therefore only be tested using a battery

overnight.

negative

(see

“Booster battery

(jump)

condition indicator or a voltmeter.

11 Specially rapid `boost’ charges which are

starting”). This also applies when connecting

5 A Delco type maintenance-free battery is

claimed to restore the power of the battery in

a battery charger.

fitted with a built-in charge condition

1 to 2 hours are not recommended, as they

Never disconnect the battery terminals, the

indicator. The indicator is located in the top of

can cause serious damage to the battery

alternator, any electrical wiring or any test

the battery casing, and indicates the condition

plates through overheating.

instruments when the engine is running.

of the battery from its colour. If the indicator

12 While charging the battery, note that the

Do not allow the engine to turn the

shows green, then the battery is in a good

temperature of the electrolyte should never

alternator when the alternator is disconnected.

state of charge. If the indicator turns darker,

exceed 37.8ºC (100ºF).

Never

“test” for alternator output by

eventually to black, then the battery requires

‘flashing’ the output lead to earth.

charging, as described later in this Section. If

Maintenance-free battery -

Never use an ohmmeter of the type

the indicator shows clear/yellow, then the

charging

incorporating a hand-cranked generator for

electrolyte level in the battery is too low to

Note: The following is intended as a guide

circuit or continuity testing.

allow further use, and the battery should be

only. Always refer to the manufacturer’s

Always ensure that the battery negative

renewed. Do not attempt to charge, load or

recommendations (often printed on a label

lead is disconnected when working on the

jump start a battery when the indicator shows

attached to the battery) before charging a

electrical system.

clear/yellow (see illustration).

battery.

Before using electric-arc

welding

6 If testing the battery using a voltmeter,

13 This battery type takes considerably

equipment on the car, disconnect the battery,

connect the voltmeter across the battery and

longer to fully recharge than the standard

alternator and components such as the fuel

compare the result with those given in the

type, the time taken being dependent on the

injection/ignition electronic control unit to

Specifications under “charge condition”. The

extent of discharge, but it can take anything

protect them from the risk of damage.

test is only accurate if the battery has not

up to three days.

been subjected to any kind of charge for the

14 A constant voltage type charger is

previous six hours. If this is not the case,

2 Electrical fault finding - general

required, to be set, when connected, to 13.9

switch on the headlights for 30 seconds, then

to 14.9 volts with a charger current below 25

information

wait four to five minutes before testing the

amps. Using this method, the battery should

battery after switching off the headlights. All

be usable within three hours, giving a voltage

Refer to Chapter 12.

other electrical circuits must be switched off,

reading of 12.5 volts, but this is for a partially

so check that the doors and tailgate are fully

discharged battery and, as mentioned, full

shut when making the test.

charging can take considerably longer.

3 Battery - testing and charging

7 If the voltage reading is less than 12.2 volts,

15 If the battery is to be charged from a fully

then the battery is discharged, whilst a

discharged state (condition reading less than

reading of

12.2 to

12.4 volts indicates a

12.2 volts), have it recharged by your Vauxhall

Standard and low maintenance

partially discharged condition.

dealer or local automotive electrician, as the

battery - testing

8 If the battery is to be charged, remove it

charge rate is higher and constant supervision

from the vehicle (Section 4) and charge it as

1 If the vehicle covers a small annual mileage

during charging is necessary.

described later in this Section.

it is worthwhile checking the specific gravity

of the electrolyte every three months to

determine the state of charge of the battery.

Use a hydrometer to make the check and

compare the results with the following table.

Note that the specific gravity readings assume

an electrolyte temperature of 15ºC (60ºF); for

every 10ºC (48ºF) below 15ºC (60ºF) subtract

0.007. For every 10ºC (48ºF) above 15ºC

(60ºF) add 0.007.

Ambient temperature, 25ºC (77ºF)

above

below

Fully-charged

1.21 to 1.23

1.27 to 1.29

70% charged

1.17 to 1.19

1.23 to 1.25

Fully-discharged

1.05 to 1.07

1.11 to 1.13

2 If the battery condition is suspect, first

check the specific gravity of electrolyte in

each cell. A variation of

0.040 or more

between any cells indicates loss of electrolyte

3.5 Battery condition indicator on maintenance-free type battery

Starting and charging systems 5A•3

brushes at a reasonable cost. However, check

on the cost of repairs before proceeding as it

4 Battery - removal and refitting

may prove more economical to obtain a new

or exchange alternator.

Removal

1 The battery is located on the left-hand side

9 Starting system - testing

of the engine bay.

2 Slacken the clamp nut and bolt on the

Note: Refer to the precautions given in

negative (-) terminal clamp (see illustration).

“Safety first!” and in Section 1 of this Chapter

Lift the clamp off the terminal post. If the

before starting work.

clamp is stuck to the post, beware of using

1 If the starter motor fails to operate when the

force to free it as the post may be broken.

4.2 Disconnect the battery negative

ignition key is turned to the appropriate

Warm water will usually do the trick.

terminal first

position, the following possible causes may

3 Similarly disconnect the positive (+) terminal;

be to blame.

this may be protected by a plastic cover.

7 If the regulated voltage is not as stated, the

a) The battery is faulty.

4 Undo the clamp bolt at the base of the

fault may be due to worn brushes, weak brush

b) The electrical connections between the

battery and lift out the battery. Be careful, it is

springs, a faulty voltage regulator, a faulty

switch, solenoid, battery and starter

heavy. Keep it upright and do not drop it.

diode, a severed phase winding or worn or

motor are somewhere failing to pass the

damaged slip rings. The alternator should be

Refitting

necessary current from the battery

renewed or taken to an auto-electrician for

through the starter to earth.

5 Refit in the reverse order to removal,

testing and repair.

c) The solenoid is faulty.

connecting the earth (negative) lead last. Use

d) The starter motor is mechanically or

a little proprietary anti-corrosion compound,

6 Alternator drivebelt - removal,

electrically defective.

or petroleum jelly, on the terminal posts. Do

refitting and tensioning

2 To check the battery, switch on the

not overtighten the clamp bolt or the terminal

headlights. If they dim after a few seconds,

clamps.

Refer to the procedure given for the

this indicates that the battery is discharged -

auxiliary drivebelt(s) in Chapter 1.

recharge (see Section 3) or renew the battery.

If the headlights glow brightly, operate the

5 Charging system - testing

ignition switch and observe the lights. If they

7 Alternator - removal and

dim, then this indicates that current is

Note: Refer to the warnings given in “Safety

refitting

reaching the starter motor, therefore the fault

first!” and in Section 1 of this Chapter before

must lie in the starter motor. If the lights

starting work.

continue to glow brightly (and no clicking

Removal

1 If the ignition warning light fails to illuminate

sound can be heard from the starter motor

1 Disconnect the battery earth

(negative)

when the ignition is switched on, first check

solenoid), this indicates that there is a fault in

the alternator wiring connections for security.

lead.

the circuit or solenoid

- see following

2 Make a note of the electrical connections at

If satisfactory, check that the warning light

paragraphs. If the starter motor turns slowly

bulb has not blown, and that the bulbholder is

the rear of the alternator, then disconnect the

when operated, but the battery is in good

multi-plug, spade terminals or other

secure in its location in the instrument panel.

condition, then this indicates that either the

connectors as appropriate.

If the light still fails to illuminate, check the

starter motor is faulty, or there is considerable

3 Remove the alternator strap bolts, noting

continuity of the warning light feed wire from

resistance somewhere in the circuit.

the short earth lead which links the alternator

the alternator to the bulbholder. If all is

3 If a fault in the circuit is suspected,

to the engine. Slacken the pivot bolt, swing

satisfactory, the alternator is at fault and

disconnect the battery leads (including the

the alternator towards the engine and remove

should be renewed or taken to an auto-

earth connection to the body), the

the drivebelt.

electrician for testing and repair.

starter/solenoid

wiring

and

the

4 Remove the pivot bolt and lift off the

2 If the ignition warning light illuminates when

engine/transmission earth strap. Thoroughly

alternator. On one car examined, the pivot

the engine is running, stop the engine and

clean the connections, and reconnect the

bolt had been inserted from the ‘wrong’ side

check that the drivebelt is correctly tensioned

leads and wiring, then use a voltmeter or test

so that it could not be withdrawn far enough

(see Chapter

1) and that the alternator

lamp to check that full battery voltage is

to release the alternator: in this case it is

connections are secure. If all is so far

available at the battery positive lead

necessary to unbolt the alternator mounting

satisfactory, have the alternator checked by

connection to the solenoid, and that the earth

from the block.

an auto-electrician for testing and repair.

is sound. Smear petroleum jelly around the

5 Take care not to knock or drop the

3 If the alternator output is suspect even

battery terminals to prevent corrosion

alternator.

though the warning light functions correctly, the

corroded connections are amongst the most

regulated voltage may be checked as follows.

Refitting

frequent causes of electrical system faults.

4 Connect a voltmeter across the battery

4 If the battery and all connections are in

6 Refit in the reverse order to removal; tension

terminals and start the engine.

good condition, check the circuit by

the drivebelt as described in Chapter 1.

5 Increase the engine speed until the

disconnecting the wire from the solenoid

voltmeter reading remains steady; the reading

blade terminal. Connect a voltmeter or test

should be approximately 12 to 13 volts, and

lamp between the wire end and a good earth

8 Alternator - testing and overhaul

no more than 14 volts.

(such as the battery negative terminal), and

6 Switch on as many electrical accessories

check that the wire is live when the ignition

(eg, the headlights, heated rear window and

If the alternator is thought to be suspect, it

switch is turned to the `start’ position. If it is,

heater blower) as possible, and check that the

should be removed from the vehicle and taken

then the circuit is sound - if not the circuit

alternator maintains the regulated voltage at

to an auto-electrician for testing. Most auto-

wiring can be checked as described in

around 13 to 14 volts.

electricians will be able to supply and fit

Chapter 12.

5A•4 Starting and charging systems

5 The solenoid contacts can be checked by

2.0 litre 16-valve models

2 Disconnect the battery negative lead and

connecting a voltmeter or test lamp between

8 Remove the starter motor-to-transmission

disconnect the wiring from the switch/sender

the battery positive feed connection on the

bolts which are accessible from above.

(see illustration).

starter side of the solenoid, and earth. When

9 Raise and support the front of the vehicle

3 Unscrew the switch/sender and recover the

the ignition switch is turned to the `start’

(see “Jacking and Vehicle Support”). Remove

sealing washer. Be prepared for oil spillage,

position, there should be a reading or lighted

the inlet manifold bracing strap.

and if the switch is to be left removed from the

bulb, as applicable. If there is no reading or

10 Disconnect the main feed and command

engine for any length of time, plug the hole.

lighted bulb, the solenoid is faulty and should

leads from the starter motor.

11 Remove the remaining starter motor

Refitting

be renewed.

mounting bolts, not forgetting the bracket at

6 If the circuit and solenoid are proved

4 Examine the sealing washer for signs of

the brushgear end of the motor. Remove the

sound, the fault must lie in the starter motor.

damage or deterioration and if necessary

motor from below.

In this event, it may be possible to have the

renew.

starter motor overhauled by a specialist, but

Refitting

5 Refit the switch/sender, complete with

check on the cost of spares before

washer, and tighten it securely. Reconnect the

12 Refitting is the reverse of the removal

proceeding, as it may prove more economical

wiring.

procedure.

to obtain a new or exchange motor.

6 Check and, if necessary, top-up the engine

oil as described in Chapter 1.

11 Starter motor - testing and

10 Starter motor - removal and

overhaul

refitting

14 Oil level sensor (16-valve

If the starter motor is thought to be suspect,

models) - removal and refitting

it should be removed from the vehicle and

Removal

taken to an auto-electrician for testing. Most

1 Disconnect the battery earth lead.

Removal

auto-electricians will be able to supply and fit

1.2 litre models

brushes at a reasonable cost. However, check

1 Raise and support the front of the vehicle

on the cost of repairs before proceeding as it

(see “Jacking and Vehicle Support”).

2 Disconnect the battery positive leads;

may prove more economical to obtain a new

2 Disconnect the battery earth

(negative)

separate the starter motor lead from the other.

or exchange motor.

lead.

Also disconnect the positive lead from the

3 Drain the engine oil, saving it if it is fit for

alternator.

re-use.

3 Separate the gearshift linkage to improve

12 Ignition switch - removal and

4 Follow the sensor wiring back to its

access. Unbolt and remove the starter motor

refitting

connection with the main wiring harness and

from above, disconnecting the solenoid

disconnect it.

(Early type sensors have a

command lead.

Refer to Chapter 10.

wiring plug secured with two screws, which

4 If a new starter motor is being fitted,

can be disconnected at the sensor.)

transfer the electrical lead to it.

13 Oil pressure warning light

5 Remove the four screws which secure the

1.4, 1.6, 1.8 and 2.0 litre 8-valve

switch/gauge sender -

sensor to the sump. Remove the sensor and

models

removal and refitting

recover the seal.

5 Raise and support the front of the vehicle

Refitting

(see “Jacking and Vehicle Support”).

6 Note the electrical connections to the

Removal

6 Refitting is the reverse of the removal

starter solenoid, then disconnect them.

1 The switch/gauge sender is screwed into

procedure. Use a new seal. Refill the engine

7 Unbolt the starter motor and remove it from

the cylinder block or oil filter carrier

with oil on completion.

below (see illustration).

(depending on model).

10.7 Starter motor mounting bolts

13.2 Oil pressure sender wires (arrowed)

(arrowed) - engine removed for clarity

5B•1

Chapter 5 Part B:

Contact breaker ignition system

Contents

Condenser - testing, removal and refitting

General information

Contact breaker points - gap and dwell angle adjustment

Ignition HT coil - removal, testing and refitting

Contact breaker points - removal and refitting

Ignition system - testing

Distributor - overhaul

Ignition system check

See Chapter 1

Distributor - removal and refitting

Ignition timing - adjustment

Degrees of difficulty

Easy, suitable for

Fairly easy, suitable

Fairly difficult,

Difficult, suitable for

Very difficult,

novice with little

for beginner with

suitable for competent

experienced DIY

suitable for expert

experience

some experience

DIY mechanic

mechanic

DIY or professional

Specifications

General

Type

Distributor with mechanical contact breaker points

Firing order

1-3-4-2 (No 1 at crankshaft pulley end of engine)

Distributor

Rotational direction of rotor

Anti-clockwise (viewed from cap)

Contact breaker points gap

0.4 mm

Dwell angle

47 to 53º

Timing*

10º BTDC (crankshaft pulley notch and timing cover rib in alignment)

*Refer to text for information on usage of unleaded petrol

Ignition coil

Primary winding resistance (approximate)

1.2 to 1.6 ohm

Secondary winding resistance (approximate)

7k ohms

Torque wrench settings

lbf ft

Spark plugs

4 The high tension circuit consists of the high

7 The ignition advance is controlled both

tension or secondary coil winding, the heavy

mechanically and by a vacuum-operated

1 General information

ignition lead from the centre of the coil to the

system. The mechanical governor comprises

centre of the distributor cap, the rotor arm,

two weights, which move out from the

1 In order that the engine can run correctly it

and the spark plug leads and spark plugs.

distributor shaft as the engine speed rises due

is necessary for an electrical spark to ignite

5 The system functions in the following

to centrifugal force. As they move outwards

the fuel/air mixture in the combustion

manner. Low tension voltage is changed in

they rotate the cam relative to the distributor

chamber at exactly the right moment in

the coil into high tension voltage by the

shaft, and so advance the spark. The weights

relation to engine speed and load. The ignition

opening and closing of the contact breaker

are held in position by two light springs and it

system is based on feeding low tension

points in the low tension circuit. High tension

is the tension of the springs which is largely

voltage from the battery to the coil where it is

voltage is then fed via the carbon brush in the

responsible for correct spark advancement.

converted to high tension voltage. The high

centre of the distributor cap to the rotor arm

8 The vacuum control consists of a

tension voltage is powerful enough to jump

of the distributor cap, and each time it comes

diaphragm, one side of which is connected

the spark plug gap in the cylinders many

in line with one of the four metal segments in

via a small bore tube to the carburettor, and

times a second under high compression,

the cap, which are connected to the spark

the other side to the contact breaker plate.

providing that the system is in good condition

plug leads, the opening and closing of the

Depression in the inlet manifold and

and that all adjustments are correct.

contact breaker points causes the high

carburettor, which varies with engine speed

2 The ignition system is divided into two

tension voltage to build up, jump the gap from

and throttle opening, causes the diaphragm to

circuits, low tension and high tension.

the rotor arm to the appropriate metal

move, so moving the contact breaker plate,

3 The low tension circuit (sometimes known

segment and so via the spark plug lead to the

as the primary) consists of the battery, lead to

spark plug, where it finally jumps the spark

and advancing or retarding the spark.

the ignition switch, lead from the ignition

plug gap before going to earth.

9 A resistance wire in the low tension feed to

switch to the low tension or primary coil

6 The ignition is advanced and retarded

the coil keeps the coil voltage down to 6V

windings, and the lead from the low tension

automatically, to ensure that the spark occurs

during normal running. This wire is bypassed

coil windings to the contact breaker points

at just the right instant for the particular load

when the starter motor is operating, to

and condenser in the distributor.

at the prevailing engine speed.

compensate for reduced battery voltage.

5B•2 Contact breaker ignition system

distributor cap is cracked, the rotor arm is

17 If there is still no spark, examine the

faulty or the carbon brush in the top of the

distributor cap carefully for tracking. This can

2 Ignition system - testing

distributor cap is not making good contact

be recognised by a very thin black line running

with the spring on the rotor arm.

between two or more electrodes, or between

8 If there are no sparks from the end of the

an electrode and some other part of the

1 By far the majority of breakdown and

running troubles are caused by faults in the

lead from the coil, check the connections at

distributor. These lines are paths which now

the coil end of the lead. If it is in order start

conduct electricity across the cap thus letting

ignition system either in the low tension or

high tension circuits.

checking the low tension circuit. Possibly, the

it run to earth. The only answer is a new

points are in bad condition. Clean and reset

distributor cap.

2 There are two main symptoms indicating

faults. Either the engine will not start or fire, or

them as described in this Chapter, Section 3.

18 Apart from the ignition timing being

9 Use a 12V voltmeter or a 12V bulb and two

incorrect, other causes of misfiring have

the engine is difficult to start and misfires. If it

is a regular misfire, (ie the engine is running on

lengths of wire. With the ignition switched on

already been dealt with under the Selection

and the points open, test between the low

dealing with the failure of the engine to start.

only two or three cylinders), the fault is almost

sure to be in the secondary or high tension

tension wire to the coil and earth. No reading

To recap, these are that:

circuit. If the misfiring is intermittent the fault

indicates a break in the supply from the

a) The coil may be faulty giving an

could be in either the high or low tension

ignition switch. Check the connections at the

intermittent misfire.

circuits. If the car stops suddenly, or will not

switch to see if any are loose. Refit them and

b) There may be a damaged wire or loose

start at all, it is likely that the fault is in the low

the engine should run. A reading shows a

connection in the low tension circuit.

tension circuit. Loss of power and

faulty coil or condenser, or broken lead

c) The condenser may be faulty.

between the coil and the distributor.

d) There may be a mechanical fault in the

overheating, apart from faulty carburation

settings, are normally due to faults in the

10 Take the condenser wire off the points

distributor (broken driving spindle or

assembly and with the points open test

contact breaker spring).

distributor or to incorrect ignition timing.

between the moving point and earth. If there

19 If the ignition timing is too far retarded, it

Engine fails to start

is now a reading then the fault is in the

should be noted that the engine will tend to

3 If the engine fails to start and the car was

condenser. Fit a new one and the fault is

overheat, and there will be a quite noticeable

running normally when it was last used, first

cleared.

drop in power. If the engine is overheating and

check that there is fuel in the petrol tank. If the

11 With no reading from the moving point to

the power is down, and the ignition timing is

engine turns over normally on the starter

earth, take a reading between earth and the

correct, then the carburettor should be

motor and the battery is evidently well

distributor terminal of the coil A reading here

checked, as it is likely that this is where the

charged, then the fault may be in either the

shows a broken wire which will need to be

fault lies.

high or low tension circuits. First check the HT

replaced between the coil and the distributor.

circuit.

No reading confirms that the coil has failed

3 Contact breaker points - gap

4 One of the commonest reasons for bad

and must be renewed, after which the engine

and dwell angle adjustment

starting is wet or damp spark plug leads and

will run once more. Remember to refit the

distributor. Remove the distributor cap. If

condenser wire to the points assembly. For

condensation is visible internally dry the cap

these tests it is sufficient to separate the

1 To adjust the contact breaker points so that

with a rag and also wipe over the leads. Refit

points with a piece of dry paper while testing

the correct gap is obtained, first undo the two

the cap. If the engine fails to start due to either

with the points open.

distributor cap retaining screws, lift off the

damp HT leads or distributor cap, a moisture

cap and withdraw the rotor arm from the

Engine misfires

distributor shaft. At this stage it is a good idea

dispersant can be very effective. To prevent

the problem recurring, a proprietry damp start

12 If the engine misfires regularly, run it at a

to clean the inside and outside of the cap and

product can be used to provide a sealing

fast idling speed. Pull off each of the plug

inspect its condition. It is unlikely that the four

coat, so excluding any further moisture from

caps in turn and listen to the note of the

segments inside the cap will be badly burned

the ignition system. In extreme difficulty, a

engine. Hold the plug cap in a dry cloth or

or corroded, but if they are the cap must be

proprietry cold start product will help to start a

with a rubber glove as additional protection

renewed. If only a small deposit is on the

car when only a very poor spark occurs.

against a shock from the HT supply.

segments, it may be scraped away using a

5 If the engine still fails to start, check that

13 No difference in engine running will be

small screwdriver.

voltage is reaching the plugs by disconnecting

noticed when the lead from the defective

2 Push in the carbon brush located in the

each plug lead in turn at the spark plug end,

circuit is removed. Removing the lead from

centre of the cap several times to ensure that

and holding the end of the cable with rubber or

one of the good cylinders will accentuate the

it moves freely. The brush should protrude by

an insulated tool about 6 mm away from the

misfire.

at least 6 mm.

cylinder block. Spin the engine on the starter

14 Remove the plug lead from the plug which

3 Gently prise the contact breaker points

motor. Note Do not operate the starter system

is not firing and hold it about 6 mm away from

open to examine the condition of their faces. If

with the plug leads disconnected in any other

the block. Restart the engine. If the sparking is

they are rough, pitted or dirty it will be

way to that described, or damage to system

fairly strong and regular, the fault must lie in

necessary to remove them to enable new

components may result.

the spark plug.

points to be fitted.

6 Sparking between the end of the cable and

15 The plug may be loose, the insulation may

4 Assuming that the points are in a

the block should be fairly strong with a regular

be cracked, or the points may have burnt

satisfactory condition, or that they have been

blue spark. If voltage is reaching the plugs,

away giving too wide a gap for the spark to

renewed, the gap between the two faces

then remove them and clean and regap them.

jump. Worse still, one of the points may have

should be measured using feeler blades as

The engine should now start.

broken off. Either renew the plug, or clean it,

follows.

7 If there is no spark at the plug leads, take

reset the gap, and then test it.

5 Pull off the plug leads, after marking them

off the HT lead from the centre of the

16 If there is no spark at the end of the plug

to ensure correct refitment, and then remove

distributor cap and hold it to the block as

lead, or if it is weak and intermittent, check

the spark plugs.

before. Spin the engine on the starter once

the ignition lead from the distributor to the

6 With the transmission in gear and the

more. A rapid succession of blue sparks

plug. If the insulation is cracked or perished,

handbrake released, slowly pull the car

between the end of the lead and the block

renew the lead. Check the connections at the

forward, while at the same time watching the

indicates that the coil is in order and that the

distributor cap.

distributor, until the heel of the contact

Contact breaker ignition system 5B•3

of one type of meter is outlined as follows.

Refitting

12 To set the dwell angle, remove the

5 Locate the new contact set on the

distributor cap and rotor arm and connect one

baseplate and refit the retaining screw.

lead of the dwell meter to the ‘+’ terminal (15)

6 Move the contact breaker spring blade away

on the coil and the other lead to the ‘-’

from the insulator, fit the low tension and

terminal (1 ) on the coil.

condenser leads and allow the spring blade to

13 Whilst an assistant turns on the ignition

slip back into place. Make sure that the leads

and operates the starter, observe the reading

and the blade locate squarely in the insulator.

on the dwell meter scale. With the engine

7 Check and adjust the contact breaker

turning on the starter the reading should be as

points gap or dwell angle, as described in

stated in the Specifications.

Section

3, then refit the rotor arm and

Note: Fluctuation of the dwell meter needle

distributor cap.

indicates that the engine is not turning over

3.6 Checking the contact breaker points

fast enough to give a steady reading. If this is

gap using a feeler blade

the case, remove the spark plugs and repeat

5 Condenser - testing, removal

the checks.

and refitting

breaker arm is on the peak of one of the four

14 If the dwell angle is too small, the contact

cam lobes. A feeler blade equal to the contact

breaker point gap is too wide, and if the dwell

breaker points gap, as given in the

Testing

angle is excessive the gap is too small.

Specifications, should now just fit between

15 Adjust the contact breaker points gap,

1 The purpose of the condenser is to prevent

the contact faces (see illustration). Make

using the method described in paragraph 7,

excessive arcing of the contact breaker

sure that the feeler blade is clean - if the

until the correct dwell angle is obtained.

points, and to ensure that a rapid collapse of

contact faces are contaminated with oil or

16 When the dwell angle is satisfactory,

the magnetic field, created in the coil and

grease, the LT current will be greatly reduced

disconnect the meter and refit the rotor arm,

necessary if a healthy spark is to be produced

and malfunction will result.

distributor cap and, if removed, the spark

at the plugs, is allowed to occur.

7 If the gap varies from this amount, slacken

plugs and leads.

2 The condenser is fitted in parallel with the

the contact breaker plate retaining screw and

17 Check the ignition timing, as described in

contact breaker points. If it becomes faulty it

move the breaker plate in or out to achieve

Section 8.

will cause ignition failure, as the points will be

the desired gap. The plate can be easily

prevented from cleanly interrupting the low

moved with a screwdriver inserted between

tension circuit

the notch in the breaker plate and the two

4 Contact breaker points -

3 If the engine becomes very difficult to start,

adjacent pips in the distributor baseplate.

removal and refitting

or begins to miss after several miles of

8 When the gap is correct, tighten the

running, and the contact breaker points show

retaining screw and then recheck the gap.

1 When significant pitting or burning of the

signs of excessive burning, then the condition

9 Refit the rotor arm, distributor cap, spark

contact faces has occurred, the contact set

of the condenser must be suspect. A further

plugs and leads.

should be renewed. It is not an expensive item

test can be made by separating the points by

10 If a dwell meter is available, a far more

and is worth renewing as a preventive

hand, with the ignition switched on. If this is

accurate method of setting the contact

measure at alternate service intervals, even if

accomplished by an excessively strong flash,

breaker points gap is by measuring and

apparently still in good condition.

it indicates that the condenser has failed.

setting the distributor dwell angle.

4 Without special test equipment, the only

11 The dwell angle is the number of degrees

Removal

reliable way to diagnose condenser trouble is

of distributor cam rotation during which the

2 Undo the two distributor cap retaining

to renew the suspect unit and note if there is

contact breaker points are closed, ie the

screws, lift off the cap and withdraw the rotor

any improvement in performance. It is not an

period from when the points close after being

arm from the distributor shaft

(see

expensive component and it is worth

opened by one cam lobe until they are

illustration).

considering periodic renewal on a preventive

opened again by the next cam lobe. The

3 Move the contact breaker arm spring blade

basis, to avoid the inconvenience entailed by

advantages of setting the points by this

away from the plastic insulator and slip the

failure in use.

method are that any wear of the distributor

low tension and condenser lead terminals off

shaft or cam lobes is taken into account, and

the insulator (see illustration).

Removal

also the inaccuracies of using a feeler blade

4 Undo the retaining screw securing the

5 To remove the condenser from its location

are eliminated. In general, a dwell meter

contact breaker plate to the distributor

in the distributor, undo the distributor cap

should be used in accordance with the

baseplate and lift off the contact set (see

retaining screws, lift off the cap and withdraw

manufacturer’s instructions. However, the use

illustration).

the rotor arm from the distributor shaft.

4.2 Removing the rotor arm

4.3 Slip the low tension and condenser

4.4 Undoing the points retaining screw

leads out of the insulator

5B•4 Contact breaker ignition system

6.3 Ignition timing marks (arrowed) in

6.8 Correct position of oil pump driveshaft

alignment

6.7 Distributor rotor position prior to refitting

prior to fitting distributor

A LT lead grommet B No1 reference mark

6 Move the contact breaker arm spring blade

12 Refer to Section 8 and adjust the ignition

away from the plastic insulator and withdraw

the distributor shaft is in the correct position

timing.

the condenser lead.

after fitting, ie with the rotor arm pointing

7 Undo the screw securing the condenser to

towards the notch in the rim of the distributor

the distributor baseplate and lift the

body, set the shaft so that the rotor arm is

7 Distributor - overhaul

condenser off.

pointing towards the low tension lead

grommet in the side of the distributor body

Refitting

1 Remove the distributor from the engine, as

(see illustration), prior to fitting. As the skew

8 Refitting is the reverse sequence to

described in the previous Section, and then

gears mesh, the shaft will turn back to the

removal, but make sure that the condenser

correct position.

prepare a clean uncluttered working area.

and low tension leads are securely located in

2 Remove the rotor arm, ease the contact

8 It is also necessary to position the oil pump

the insulator behind the contact breaker arm

driveshaft so that it engages with the slot in

breaker arm spring blade away from the

spring blade.

plastic insulator and slip the low tension and

the distributor shaft as the distributor is

condenser leads off the insulator.

inserted. The shaft should be positioned so

3 Withdraw the low tension lead grommet

that it is at approximately

90º to the

6 Distributor - removal and

from the slot in the side of the distributor body

crankshaft centreline (see illustration).

refitting

(see illustration) and remove the lead.

9 Make sure that the O-ring seal is in position

4 Undo the retaining screw and lift off the

at the base of the distributor and, with the

contact set.

Removal

shafts set as previously described, insert the

5 Undo the retaining screw and lift off the

distributor into its location. It may take two or

1 Pull off the spark plug leads, after marking

condenser (see illustration).

three attempts to engage the oil pump

them to ensure correct refitment, and remove

6 On the side of the distributor body, undo

driveshaft, and finish with the rotor arm

the spark plugs.

the two vacuum unit securing screws.

pointing to the notch. If necessary move the

2 Undo the distributor cap retaining screws,

Withdraw the vacuum unit and at the same

distributor shaft very slightly one way or the

lift off the cap and place it to one side.

time disengage the operating arm from the

other, until the correct position is achieved.

3 With the transmission in gear and the

peg on the side of the baseplate

(see

10 With the distributor in place, turn the

handbrake released, pull the car forward until,

illustrations).

with a finger over the plug hole, compression

distributor body clockwise a few degrees so

7 Undo the two baseplate securing screws,

can be felt in No 1 cylinder (the cylinder

that the contact breaker points are closed,

noting the earth tag under one screw and the

nearest the crankshaft pulley). Continue

and then slowly turn it anti-clockwise until

spade terminal under the other

(see

moving the car forwards until the notch on the

they just open with the rotor arm once more

illustration). Withdraw the baseplate

crankshaft pulley is in line with the raised

pointing towards the notch in the distributor

assembly from the distributor body.

mark on the timing cover (see illustration).

body rim. Hold the distributor in this position

The distributor rotor arm should now be

and refit the clamp plate and clamp bolt.

8 This is the practical limit of dismantling of

pointing to the notch on the rim on the

Tighten the bolt securely.

these distributors, as none of the components

distributor body.

below the baseplate are renewable as

11 Reconnect the low tension lead and the

4 Disconnect the distributor low tension lead

separate items. If, however, it is necessary to

vacuum advance pipe. Refit the spark plugs,

at the harness connector and detach the

remove the centrifugal advance springs and

distributor cap and leads.

vacuum advance pipe from the distributor

vacuum unit.

5 Undo the distributor clamp retaining bolt,

lift off the clamp plate and withdraw the

distributor from its location.

Refitting

6 Before refitting the distributor, check that

the engine has not been inadvertently turned

whilst the distributor was removed; if it has,

return it to the original position, as described

in paragraph 3.

7 As the distributor is refitted, the distributor

shaft will rotate anti-clockwise slightly due to

the meshing action of the skew gears on the

7.3 Removing the LT lead

7.5 Undoing the condenser retaining screw

distributor shaft and camshaft. To ensure that

Content .. 5 6 7 8 ..