1988 OPEL VECTRA ignition

10Pull the weatherstrips from the rear edge
of the window aperture, then unscrew the
now-exposed window rear guide rail securing
screw. Note that the screw is of the Torx type.
11Unscrew the remaining window rear guide
rail securing screw (Torx type), which is
accessible through the inner door skin, then
withdraw the guide rail from the door. The
weatherstrip can be left attached to the guide
rail, in which case position the guide rail to
one side out of the way, taking care not to
damage the vehicle paintwork.
12Reach in through the aperture in the rear
of the door, and unclip the plastic shield from
the lock (see illustration).
13On models with central locking,
disconnect the battery negative lead (if not
already done) and disconnect the wiring plug
from the central locking motor. Note that a
clip must be depressed to release the wiring
plug.
14Unscrew the three Torx bolts securing the
lock assembly to the rear edge of the door.
Then manipulate the lock assembly (complete
with central locking motor, where applicable,
and operating rods), around the window
regulator mechanism and out through the
lower door aperture.
Refitting
15Proceed as described in paragraph 7.
22Door check arm -removal
and refitting
3
Removal
1Open the door fully, then using a punch,
drive the roll pin from the door check arm
pivot.
2Remove the door inner trim panel, as
described in Section 17.
3Working at the front edge of the door,
unscrew the two bolts securing the check arm
to the door, then withdraw the check arm
through the inside of the door.
Refitting
4Refitting is a reversal of removal, but use a
new roll pin to secure the check arm to the
pivot.
23Windscreen and rear
window - removal and refitting
5
1Except for the rear quarter windows, all
fixed glass is bonded in position, using a
special adhesive.
2Special tools, adhesives and expertise are
required for successful removal and refitting
of glass fixed by this method. Such work must
therefore be entrusted to a Vauxhall dealer or
a windscreen specialist.
3The same remarks apply if sealing of the
windscreen or other glass surround is
necessary.
24Rear quarter windows -
removal and refitting
3
Removal
1Remove the upper rear quarter trim panel,
as described in Section 36.
2Have an assistant support the quarter
window from outside the vehicle, then
unscrew the plastic securing nuts, and push
the window from the body (see illustration).
Refitting
3Refitting is a reversal of removal, but ensure
that the seal on the rear of the glass is seated
correctly against the body as the window is
fitted.
25Door window - removal and
refitting
3
Front door
Removal
1Fully lower the window, then remove the
door inner trim panel and the plastic insulating
sheet, as described in Section 17.
2Unscrew the window rear guide rail
securing bolt from the rear edge of the door,
then manipulate the guide rail out through the
lower aperture in the door.
3Pull the weatherstrips from the inside and
outside lower edge of the window aperture.
4Pull the plastic end stop from the window
upper guide rail (see illustration).
5Remove the two screws securing the lower
guide rail to the door, and lower the guide rail
(see illustration).
6Manipulate the window regulator
mechanism as necessary, and tilt the window
glass forwards until it can be withdrawn from
outside the door through the window
aperture.
Refitting
7Refitting is a reversal of removal, but adjust
the angle of the lower guide rail by means of
the two securing screws until smooth
operation of the window is achieved. Refit the
door inner trim panel with reference to
Section 17.
8On models with electric windows, on
completion, the electronic control system
must be programmed as follows.
9Close all the doors, and switch on the
ignition.
10Close each window in turn, using the
relevant switch, and when each window has
fully closed, continue to keep the switch
depressed for at least five seconds.
Rear door
Removal
11Fully lower the window, then remove the
door inner trim panel and the plastic insulating
sheet, as described in Section 17.
Bodywork and fittings 11•9
25.4 Window upper guide rail plastic end
stop (arrowed)25.5 Window lower guide rail securing
screws (arrowed)
24.2 Upper rear quarter trim panel
removed, exposing rear quarter window
securing nut (arrowed)21.12 Unclip the plastic shield from the
lock
11

4C
Torque wrench settingsNm lbf ft
AIR non-return valve to pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 22
AIR pipe support bracket to manifold . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
AIR pipe to manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
AIR pipe to support bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
AIR pump bracket to protective shield . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
AIR pump to wheel arch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
AIR pump to insulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
AIR valves to bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3
Carbon canister . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3
EGR valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
Heat shield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
Oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 22
Chapter 4 Part C:
Fuel and exhaust systems - exhaust and emissions
AIR cut-off valve - removal, testing and refitting . . . . . . . . . . . . . . . . .7
AIR pipe and non-return valve - removal and refitting . . . . . . . . . . . . .9
AIR pump assembly (Simtec system) - removal and refitting . . . . . . . .6
AIR switchover valve - removal and refitting . . . . . . . . . . . . . . . . . . . .8
Carbon canister - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .11
Catalytic converter - description, general and precautions . . . . . . . .10
EGR module (X 16 SZ models) - removal and refitting . . . . . . . . . . . . .5EGR valve (Multec system models) - testing, removal and refitting . . .3
EGR valve (Simtec system) - testing, removal and refitting . . . . . . . . .4
Emissions control systems - general . . . . . . . . . . . . . . . . . . . . . . . . . .1
Exhaust gas recirculation (EGR) system - general . . . . . . . . . . . . . . . .2
Exhaust manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . .13
Exhaust system - checking, removal and refitting . . . . . . . . . . . . . . .14
Oxygen sensor (catalytic converter models) - removal and refitting .12
4C•1
Specifications Contents
1 Emissions control systems -
general
General
Multec system
1An evaporative emissions control system is
fitted to minimise the escape into the
atmosphere of unburned hydrocarbons.
2The fuel tank filler cap is sealed and a
charcoal canister is mounted under the
right-hand front wing to collect the petrol
vapours generated in the tank when the
vehicle is parked. It stores them until they can
be purged from the canister into the inlet tract
to be burned by the engine during normal
combustion. The canister’s control valve (on
the top of the canister) is opened by a vacuum
pipe from the front of the throttle body on C16
NZ, C16 NZ2 and C18 NZ engines. On X16 SZ
it’s opened by an electronically activated
purge valve, mounted on the camshaft
housing.
Motronic system
3The system is as described in Chapter 4B,
except that the charcoal canister is purged
under the control of the fuel injection/ignition
system module through the fuel tank vent
valve. To ensure that the engine runs correctly
when it is cold and/or idling, and to protect
the catalytic converter from the effects of an
over-rich mixture, the valve is not opened by
the module until the engine is under partial or
full load. The valve solenoid is then modulated
on and off to allow the stored vapour to pass
into the inlet tract.
4Canister removal and refitting is as
described in Section 11.
5On C20 NE engines, the vent valve is
mounted above the injectors for cylinders 2
and 4. To remove it, disconnect the battery
negative lead and the valve wiring plug, then
disconnect the two vent hoses having made
note of their connections. Either remove the
valve from its mounting bracket, or unbolt the
bracket, as required.
6On C20 XE engines, the vent valve is
mounted on the left-hand end of the engine,underneath the end of the fuel injector wiring
harness housing (see illustration). Removal
and refitting is as described in the previous
paragraph.
Simtec system
7For information refer to “General
description”, in Chapter 4B. Note that “AIR”,
is an abbreviation for the secondary Air
Injection Reactor system used on this model.
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321
1.6 Disconnecting the fuel tank vent valve
wiring

2Exhaust gas recirculation
(EGR) system - general
The system reintroduces small amounts of
exhaust gas into the combustion cycle to
reduce the generation of oxides of nitrogen
(NOx).
On C16 NZ, C16 NZ2 and C18 NZ engines,
the volume of exhaust gas reintroduced is
governed by manifold vacuum, through the
EGR valve mounted on the inlet manifold.
When the valve is opened small amounts of
exhaust gas are allowed to enter the inlet
tract, passing through ports in the cylinder
head.
On X16 SZ engines the EGR valve is
operated by an EGR module, mounted on the
left-hand side of the engine compartment
behind the battery. This module amplifies
signals received from the fuel system ECU
and operates the EGR valve electronically
providing precise control of exhaust gas
recirculation under all engine conditions.
3EGR valve (Multec system
models) - testing, removal and
refitting
2
Testing
1On C16 NZ, C16 NZ2 and C18 NZ engines,
it is recommended that the system is checked
annually, by checking the movement of the
valve’s diaphragm carrier plate as follows.
Note that the carrier plate is visible only
through the apertures in the underside of the
valve, so a battery-operated torch and small
mirror may be useful. On X16 SZ engines,
Vauxhall test equipment is necessary to check
the EGR system.
2With the engine fully warmed up to normal
operating temperature and idling, briefly open
and close the throttle. The carrier plate should
move upwards as the manifold vacuum
changes. When the engine is idling smoothly
again, press the carrier plate upwards (do this
very carefully, so that the plate is not distorted or
the diaphragm damaged). The idle speed should
drop significantly (approximately 100 rpm).
3If the valve does not respond as described,
it must be cleaned.
Removal
4Pull off the hose from the valve, then unbolt
the valve and remove it (see illustrations).
Clean away all carbon using a wire brush and
a pointed tool, but take care not to damage
the valve seat. Renew the valve gasket to
prevent induction leaks.
Refitting
5Refit the valve and reconnect the hose,
then recheck the system’s performance; if
there is no improvement, the valve must be
renewed.
4EGR valve (Simtec system) -
testing, removal and refitting
3
Note: A new gasket will be required when
refitting the valve.
Removal
1Disconnect the battery negative lead.
2Remove wiring harness and vacuum hose.
3Mark position of the valve, to ensure
correct relocation.
4Undo the 3 bolts, and remove the valve
from the dual spark ignition coil’s coolant
flange.
Refitting
5Clean the sealing surfaces of the valve and
flange.
6Refit the valve with a new gasket and line
up the marks made before removal (see
illustration).
5EGR module (X16 SZ
models) - removal and
refitting
2
Removal
1Disconnect the knock module from its
bracket (refer to Chapter 4B, if necessary),
and place to one side.
2Remove wiring plug from module. Remove
module from bracket.
Refitting
3Refitting is a reversal of removal.
6AIR pump assembly (Simtec
system) - removal and refitting
3
Removal
1Chock the rear wheels, jack up the front of
the vehicle and support it on axle stands
placed under the body side members (see
“Jacking and Vehicle Support”)
2Remove the left hand front wheel and inner
wheel arch lining.
3Loosen the hose clamp and remove the air
duct hose from the pump.
4Disconnect the battery negative lead.
5Undo the securing nuts and remove the
pump assembly from its location. Disconnect
the wiring plug.
6Remove the wiring plug from the pump’s
bracket.
7Mark the position of the pump on it’s
bracket before separating.
8Remove the fixing bolts and disconnect the
pump from it’s insulator.
9The insulator can also be checked by
removing the 3 nuts, securing the protective
shield. Before removing, mark the shield and
insulator. Replace if necessary.
10Check the pump’s air cleaner for damage.
Refitting
11Refitting is a reversal of removal. Ensure
correct alignment of the components.
7AIR cut-off valve - removal,
testing and refitting
3
Removal
1Before removal, mark on the cut-off valve,
the direction of flow towards the non-return
valve (see illustration).
2Disconnect and remove the air duct and
vacuum hoses.
3Undo the switchover valve’s bolts and
move to one side.
4C•2Fuel and exhaust systems - exhaust and emissions
3.4 Disconnecting the vacuum hose from
the exhaust gas recirculation valve
4.6 EGR valve
1 Valve 2 Gasket
3.4B Withdrawing the exhaust gas
recirculation valve

b)Always keep the ignition and fuel systems
well maintained according to the
manufacturers schedule (see “Routine
maintenance” and the relevant Chapter).
In particular, ensure that the air cleaner
filter element, the fuel filter and the spark
plugs are renewed at the correct intervals.
If the inlet air/fuel mixture is allowed to
become too rich due to neglect, the
unburned surplus will enter and burn in
the catalytic converter, overheating the
element and eventually destroying the
converter.
c)If the engine develops a misfire, do not
drive the vehicle at all (or at least as little
as possible) until the fault is cured. The
misfire will allow unburned fuel to enter
the converter, which will result in its
overheating, as noted above.
d)The engine control indicator (the outline
of an engine with a lightning symbol
superimposed), will light when the ignition
is switched on and the engine is started,
then it will go out. While it may light briefly
while the engine is running, it should go
out again immediately and stays unlit. If it
lights and stays on while the engine is
running, seek the advice of a Vauxhall
dealer as soon as possible. A fault has
occurred in the fuel injection/ignition
system that, apart from increasing fuel
consumption and impairing the engine’s
performance, may damage the catalytic
converter.
e)DO NOT push or tow-start the vehicle.
This will soak the catalytic converter in
unburned fuel causing it to overheat when
the engine does start see (b) above.
f)DO NOT switch off the ignition at high
engine speeds. If the ignition is switched
off at anything above idle speed,
unburned fuel will enter the (very hot)
catalytic converter, with the possible risk
of its igniting on the element and
damaging the converter.
g)DO NOT use fuel or engine oil additives.
These may contain substances harmful to
the catalytic converter.
h)DO NOT continue to use the vehicle if the
engine burns oil to the extent of leaving a
visible trail of blue smoke. The unburned
carbon deposits will clog the converter
passages and reduce its efficiency; in
severe cases the element will overheat.
i)Remember that the catalytic converter
operates at very high temperatures hence
the heat shields on the vehicle’s under-
body and the casing will become hot
enough to ignite combustible materials
that brush against it. DO NOT, therefore,
park the vehicle in dry undergrowth, over
long grass or over piles of dead leaves.
j)Remember that the catalytic converter is
FRAGlLE. Do not strike it with tools during
servicing work. Take great care when
working on the exhaust system. Ensure
that the converter is well clear of any
jacks or other lifting gear used to raise thevehicle. Do not drive the vehicle over
rough ground, road humps, etc., in such a
way as to ground the exhaust system.
k)In some cases, particularly when the
vehicle is new and/or is used for
stop/start driving, a sulphurous smell (like
that of rotten eggs) may be noticed from
the exhaust. This is common to many
catalytic converter-equipped vehicles and
seems to be due to the small amount of
sulphur found in some petrol’s reacting
with hydrogen in the exhaust to produce
hydrogen sulphide (CS) gas. While this
gas is toxic, it is not produced in sufficient
amounts to be a problem. Once the
vehicle has covered a few thousand miles
the problem should disappear. In the
meanwhile a change of driving style or of
the brand of petrol may effect a solution.
l)The catalytic converter, used on a
well-maintained and well-driven vehicle,
should last for between 50 000 and 100
000 miles. From this point on, careful
checks should be made at all specified
service intervals of the CO level to ensure
that the converter is still operating
efficiently. If the converter is no longer
effective it must be renewed.
11Carbon canister - removal
and refitting
3
Removal
1Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands placed under the body side members
(see “Jacking and Vehicle Support”).
2Remove the front right hand wheel and
wheel arch liner.
3Note the hose and pipe connections to the
canister, or label them, to ensure that they are
reconnected to their original unions, then
disconnect them (see illustration). Unscrew
the two nuts securing the canister mounting
bracket to the vehicle body.
Refitting
4Refitting is a reversal of removal, however
ensure correct fitment of hose and pipes.
12Oxygen sensor (catalytic
converter models) - removal
and refitting
3
Note: This sensor is also known as a Lambda
sensor.
Removal
1Disconnect the battery negative lead.
2Disconnect the oxygen sensor wiring plug,
which is located behind the coolant expansion
tank.
3Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands placed under the body side members.
4On DOHC models, remove the engine
undershield, as described in Chapter 11.
5On models fitted with Multec injection
system, the sensor is screwed into the
exhaust manifold. Trace the wiring from the
sensor itself to the connector (either clipped
to the radiator cooling fan shroud or behind
the coolant expansion tank). Release it from
any clips or ties; disconnect the wiring before
unscrewing the sensor.
6On other models, unscrew the oxygen
sensor from the front section of the exhaust
system (see illustration). It is advisable to
wear gloves, as the exhaust system will be
extremely hot.
7Withdraw the oxygen sensor and its wiring,
taking care not to burn the wiring on the
exhaust system. If the sensor is to be re-used,
take care that the sealing ring is not lost, and
that the sensor is not dropped.
Refitting
8If a new sensor is being fitted, it will be
supplied with the threads coated in a special
grease to prevent it seizing in the exhaust
system.
9If the original sensor is being refitted,
ensure that the screw thread is clean. Coat
the thread with a lithium based copper grease
(i.e. Vauxhall Part No. 90295397).
10Refitting is a reversal of removal. Check
the exhaust system for leakage when the
engine is re-started.
4C•4Fuel and exhaust systems - exhaust and emissions
12.6 Oxygen sensor location in front
section of exhaust system - DOHC models
11.3 Charcoal canister
A Vent to atmosphere
B Vapour feed hose from filler pipe
C Vapour exhaust hose to inlet tract
D Control valve vacuum pipe from
throttle body

Rear discs
Type (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Solid
Diameter (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .260 mm
Maximum disc run-out (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1 mm
Minimum pad friction material thickness (including backing plate):
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.0 mm
Minimum disc thickness after machining (all models) * . . . . . . . . . . . . .8.0 mm
* When this dimension is reached, only one further new set of disc pads is permissible, then renew the discs
Minimum handbrake shoe friction material thickness (lining only)
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.0 mm
Rear drums
Internal diameter (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200 mm
Minimum shoe friction material thickness (all models) . . . . . . . . . . . . . .0.5 mm above rivet heads
Brake fluid type/specification:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Lubricants and fluidsin “Weekly checks”
Torque wrench settingsNmlbf ft
ABS hydraulic modulator mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
ABS wheel sensor mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
ABS control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.51
Brake fluid line unions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1612
Caliper and wheel cylinder bleed screws . . . . . . . . . . . . . . . . . . . . . . . .97
Front brake disc securing screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Front brake fluid hose to caliper union . . . . . . . . . . . . . . . . . . . . . . . . . .4030
Front caliper bracket to hub carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . .9570
Front caliper guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3022
Front caliper mounting (solid disc models) . . . . . . . . . . . . . . . . . . . . . . .9570
Front caliper to mounting bracket (vented disc models) . . . . . . . . . . . .3022
Handbrake lever securing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
Master cylinder mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2216
Master cylinder stop screw (ATE type) . . . . . . . . . . . . . . . . . . . . . . . . . .64
Pressure proportioning valve to master cylinder:
ATE type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129
GMF type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4030
Rear brake backplate/stub axle spring:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5037
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle-tighten a further 30º
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle-tighten a further 15º
Rear brake disc securing screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Rear caliper mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8059
Rear drum securing screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Rear wheel cylinder mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97
Vacuum servo support bracket to bulkhead . . . . . . . . . . . . . . . . . . . . .2216
Vacuum servo to support bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
1General description
The foot brake operates on all four wheels.
Solid or ventilated disc brakes are fitted at the
front, and self-adjusting drum or solid disc
brakes are fitted at the rear, depending on
model. Actuation is hydraulic, with vacuum
servo assistance. The handbrake is cable-
operated, and acts on the rear wheels only.
The hydraulic system is split into two
circuits. On non-ABS models, the system is
split diagonally, and on ABS models, the
system is split front and rear. If there is a
hydraulic fluid leak in one circuit, the
remaining circuit will still function, so that
some braking capability remains.
The hydraulic fluid supply to the rear brakes
is regulated so that the front brakes alwayslock first under heavy braking. The fluid
pressure to the rear brakes is controlled by
two valves, one for each brake, which are
either screwed into the master cylinder or
mounted on the rear underbody of the vehicle,
depending on model.
The brake servo is of the direct-acting type,
fitted between the pedal and the master
cylinder. The servo is powered by vacuum
developed in the inlet manifold. Should the
servo fail, the brakes will still operate, but
increased pedal pressure will be required.
2Anti-lock braking system
(ABS) - general
1ABS is available as an option for all models.
When the ignition is switched on, an ‘ABS’
symbol illuminates in the instrument panel for
a short time. 2The system comprises an electronic control
unit, roadwheel sensors, hydraulic modulator,
and the necessary valves and relays. Disc
brakes are fitted to all four wheels. The
purpose of the system is to stop wheel(s)
locking during heavy brake applications. This
is achieved by automatic release of the brake
on the locked wheel, followed by re-
application of the brake. This procedure is
carried out several times a second by the
hydraulic modulator.
3The modulator is controlled by the
electronic control unit, which itself receives
signals from the wheel sensors, which monitor
the locked or unlocked state of the wheels.
The two front brakes are modulated
separately, but the two rear brakes are
modulated together.
4The ABS unit is fitted between the brake
master cylinder and the brakes, the vacuum
servo and master cylinder being of similar
type for both non-ABS and ABS models.
9•2Braking system

5If the ‘ABS’ symbol, in the instrument panel
stays lit after approximately 4 seconds, or if it
comes on sporadically or stays on whilst
driving, there is a fault in the system. Should
this occur, it is recommended that a complete
test is carried out by a Vauxhall dealer, who
will have the necessary specialist diagnostic
equipment. Due to the special equipment
required, it is not practical for the DIY
mechanic to carry out the test procedure.
6To prevent possible damage to the
electronic control unit, always disconnect the
control unit wiring plug before carrying out
electrical welding work.
7It is recommended that the control unit is
removed if the vehicle is being subjected to
high temperatures, like for instance, during
certain paint-drying processes.
8If using steam cleaning equipment, do not
aim the water/steam jet directly at the control
unit.
9Do not disconnect the control unit wiring
plug with the ignition switched on.
10Do not use a battery booster to start the
engine.
11After working on the ABS components,
ensure that all wiring plugs are correctly
reconnected, and have the complete system
tested by a Vauxhall dealer, at the earliest
opportunity.
12All models up to 1991 that were fitted with
ABS, used the ABS-2E system. From 1992
onwards an ABS-2EH system was fitted,
which can be identified by the location of the
electronic control module, which is bolted to
the hydraulic modulator.
13The main differences between the two
systems are in the electrical components and
circuits, the most obvious of these being
omission of the surge arrester relay on the
2EH system.
3Hydraulic system - bleeding
2
General
1If any of the hydraulic components in the
braking system have been removed or
disconnected, or if the fluid level in the
reservoir has been allowed to fall appreciably,
it is certain that air will have entered into the
system. The removal of all this air from the
hydraulic system is essential if the brakes are
to function correctly, and the process of
removing it is known as bleeding.
2Where an operation has only affected one
circuit of the hydraulic system (the system issplit diagonally on non-ABS models, and front
and rear on ABS models), then it will only be
necessary to bleed the relevant circuit. If the
master cylinder has been disconnected and
reconnected, or the fluid level has been
allowed to fall appreciably, then the complete
system must be bled.
3One of three methods can be used to bleed
the system, although Vauxhall recommend
the use of a pressure bleeding kit.
Bleeding - two-man method
4Obtain a clean jar, and a length of rubber or
plastic bleed tubing that will fit the bleed
screws tightly. The help of an assistant will be
required.
5Remove the dust cap and clean around the
bleed screw on the relevant caliper of wheel
cylinder (see illustration), then attach the
bleed tube to the screw. If the complete
system is being bled, start at the front of the
vehicle. When bleeding the complete system
on models with ABS, the front brakes must be
bled before the rears.
6Check that the fluid reservoir is topped up,
and then destroy the vacuum in the brake
servo by giving several applications of the
brake pedal.
7Immerse the open end of the bleed tube in
the jar, which should contain two or three
inches of hydraulic fluid. The jar should be
positioned about 300 mm (12.0 in) above the
bleed screw to prevent any possibility of air
entering the system down the threads of the
bleed screw when it is slackened.
8Open the bleed screw half a turn, and have
the assistant depress the brake pedal slowly
to the floor. With the brake pedal still
depressed, retighten the bleed screw, and
then have the assistant quickly release the
pedal. Repeat the procedure.
9Observe the submerged end of the tube in
the jar. When air bubbles cease to appear,
tighten the bleed screw when the pedal is
being held fully down by the assistant.
10Top-up the fluid reservoir. It must be kept
topped up throughout the bleeding
operations. If the connecting holes to the
master cylinder are exposed at any time due
to low fluid level, the air will be drawn into the
system, and the whole bleeding process will
have to start again.
11If the complete system is being bled, the
procedure should be repeated on the
diagonally opposite rear brake. Then on the
front and rear brakes of the other circuit on
non-ABS models, or on the remaining front
brake and then on the rear brakes on ABS
models.
12On completion, remove the bleed tube,
and discard the fluid that has been bled from
the system, unless it is required to make up
the level in the bleed jar. Never re-use old fluid.
13On completion of bleeding, top-up the
fluid level in the reservoir. Check the action ofthe brake pedal, which should be firm, and
free from any “sponginess” that would
indicate that air is still present in the system.
Bleeding - with one-way valve
14There are a number of one-man brake
bleeding kits currently available from motor
accessory shops. It is recommended that one
of these kits should be used whenever
possible, as they greatly simplify the bleeding
operations. They also reduce the risk of
expelled air or fluid being drawn back into the
system.
15Proceed as described in paragraphs 5
and 6.
16Open the bleed screw half a turn, then
depress the brake pedal to the floor, and
slowly release it. The one-way valve in the
bleeder device will prevent expelled air from
returning to the system at the completion of
each stroke. Repeat the operation until clear
hydraulic fluid, free from air bubbles, can be
seen coming through the tube. Tighten the
bleed screw.
17Proceed as described in paragraphs 11
to 13 inclusive.
Bleeding - with pressure
bleeding kit
18These are also available from motor
accessory shops, and are usually operated by
air pressure from the spare tyre.
19By connecting a pressurised container to
the master cylinder fluid reservoir, bleeding is
then carried out by simply opening each bleed
screw in turn and allowing the fluid to run out.
Like turning on a tap, until no air bubbles are
visible in the fluid being expelled.
20Using this method, the large reserve of
fluid provides a safeguard against air being
drawn into the master cylinder during the
bleeding operations.
21This method of bleeding is recommended
by Vauxhall.
22Begin bleeding with reference to
paragraphs 5 and 6, and continue as
described in paragraphs 11 to 13 inclusive.
Braking system 9•3
3.5 Removing the dust cap from a rear
caliper bleed screw - models with
ventilated discs
9
If brake fluid is spilt on the
paintwork, the affected area
must be washed down with
cold water immediately.
Brake fluid is an effective paint
stripper!

the earliest opportunity, take the vehicle to a
Vauxhall dealer, and have the complete
system tested, using the dedicated ABS test
equipment.
Rear wheel sensor
Removal
10Disconnect the battery negative lead.
11Where applicable, remove the wheel trim,
then loosen the relevant rear roadwheel bolts
and chock the front wheels. Jack up the rear
of the vehicle, and support on axle stands
(see “Jacking and Vehicle Support”)
positioned under the body side members.
Remove the roadwheel.
12Unclip the sensor wiring connector from
the retaining clip on the rear underbody, then
separate the two halves of the wiring
connector, prising them apart with a
screwdriver if necessary (see illustration).
13Note the routing of the sensor wiring, and,
where applicable, release it from the clips on
the underbody.
14Using a Allen key or hexagon bit, unscrew
the bolt securing the wheel sensor to the
trailing arm (or the mounting bracket on
DOHC models), then carefully lever the sensor
from its location using a screwdriver (see
illustration). Recover the seal ring.
Refitting
15Proceed as described in paragraphs 5 to 9
inclusive.
22ABS electronic control
module - removal and refitting
3
Note: Refer to Section 2 before proceeding
ABS-2E systems
Removal
1Ensure that the ignition is switched off, then
disconnect the battery negative lead.
2The control module is located under a
cover in the passenger sill, to the left-hand
side of the seat.
3Extract the three securing screws, and lift
the cover from the control module. Note that
two of the screws are covered by plastic trim
plugs. 4Lift the control module from its recess, then
release the retaining clip and disconnect the
module wiring plug. Withdraw the module
(see illustrations).
Refitting
5Refitting is a reversal of removal.
6Check that the ABS warning lamp
extinguishes when first starting the engine
after the module has been removed. At the
earliest opportunity, take the vehicle to a
Vauxhall dealer, and have the complete
system tested, using the dedicated ABS test
equipment.
ABS-2EH systems
Removal
7Ensure that the ignition is switched off, then
disconnect the battery negative lead.
8Remove the cover from the hydraulic
modulator.
9Disconnect both the wiring harness and
solenoid valve connectors.
10Relays can only be removed from control
units that have slanted covers (see
illustration). The relays for the solenoid valve
and pump motor, if removable, can now be
removed. If the unit has a flat cover, and is
faulty, the whole unit will have to be replaced.
11Undo fixing bolts and remove the control
unit.
Refitting
12Refitting is a reversal of removal. Refer
also to paragraph 6.
23ABS relays (ABS-2E systems
only) - removal and refitting
2
Note: Refer to Section 2 before proceeding.
For ABS-2EH system relays, refer to
paragraphs 7 to 12, in Section 22.
Solenoid valve and pump motor
relays
Removal
1The solenoid valve and pump motor relays
are mounted on the hydraulic modulator.
2Disconnect the battery negative lead.
3Remove the securing screw and withdraw
the plastic cover from the hydraulic
modulator.
4Pull out the appropriate relay. The small
relay is for the solenoid valve, and the large
relay is for the pump motor.
Refitting
5Refitting is a reversal of removal.
6Check that the ABS warning lamp
extinguishes when first starting the engine
after a relay has been removed. At the earliest
opportunity, take the vehicle to a Vauxhall
dealer, and have the complete system tested,
using the dedicated ABS test equipment.
Surge arrester relay
Removal
7The surge arrester relay is located in the
relay box at the left rear of the engine
compartment.
Braking system 9•17
22.4A Lift out the ABS control module . . .22.10 ABS-2EH control unit
1 Slanted cover type 2 Flat cover type22.4B . . . and release the wiring plug
retaining clip - ABS-2E system
21.14 ABS rear wheel sensor (arrowed) -
DOHC model21.12 ABS rear wheel sensor wiring
connectors (arrowed) on rear underbody -
DOHC model`
9

Idle settings (continued)
Idle mixture (CO content):
20 NE and 20 SEH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.0 max.
20 XEJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.7 to 1.2%
All other models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.3 % (at 2800 to 3200 rpm)
Fuel Pressure (regulator vacuum hose connected)
Multec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.76 bar
Motronic 4.1:
Feed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.3 to 2.7 bar
Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.3 to 1.5 bar
Motronic 1.5:
Feed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.8 to 2.2 bar
Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.3 to 1.5 bar
Motronic 2.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.0 to 2.2 bar
Motronic 2.8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.2 to 2.7 bar
Simtec 56.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .not available
Torque wrench settingsNmlbf ft
All specifications as for carburettor models except for the following:
Bracket, tank vent valve to coolant flange . . . . . . . . . . . . . . . . . . . . . . .86
Fuel distributor pipe to inlet manifold . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Fuel flow damper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
Fuel injector retainer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Fuel pressure regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.52
Fuel pump clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Idle air control stepper motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.52
Knock sensor (X16 SZ) to block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1310
Oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3022
Throttle body mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
Throttle body upper-to-lower section . . . . . . . . . . . . . . . . . . . . . . . . . . .64.5
Throttle potentiometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21.5
Throttle valve housing to inlet manifold . . . . . . . . . . . . . . . . . . . . . . . . .97
1General description
General
1All engines available within the Cavalier
range can be operated on unleaded petrol.
Refer to Chapter 5 for further details. Note
that models fitted with a catalytic converter
must only be operated on unleaded petrol,
and leaded petrol must not be used. Models
with catalytic converter can be identified by
the engine code, which is prefixed by the
letter ‘C’ or ‘X’.
Multec system
Note: There is no provision for the adjustment
or alteration of the idle speed; if checking the
idle speed, remember that it may vary
constantly under ECU control.
2The Multec system is essentially a simple
method of air/fuel metering, replacing the
carburettor with a single injector mounted in a
throttle body. This type of system is therefore
also known as Throttle Body Injection (TBi),
Central Fuel Injection (CFi) or single-(or
mono-) point injection. The whole system is
best explained if considered as three
sub-systems, these being fuel delivery, air
metering and electrical control.
3The fuel delivery system incorporates the
fuel tank (with the electric fuel pumpimmersed inside it), the fuel filter, the fuel
injector and pressure regulator (mounted in
the throttle body), and the hoses and pipes
connecting them. When the ignition is
switched on (or when the engine is cranking,
on X16 SZ engines) the pump is supplied with
voltage, by way of the pump relay and fuse
11, under the control of the Electronic Control
Unit (ECU). The pump feeds through the fuel
filter to the injector. Fuel pressure is controlled
by the pressure regulator, which lifts to allow
excess fuel to return to the tank.
4The air metering system includes the inlet air
temperature control system and the air
cleaner, but its main components are in the
throttle body assembly. This incorporates the
injector, which sprays fuel onto the back of the
throttle valve, the throttle potentiometer. This
is linked to the throttle valve spindle and sends
the ECU information on the rate of throttle
opening by transmitting a varying voltage. The
idle air control stepper motor is controlled by
the ECU to maintain the idle speed.
5The electrical side of the fuel injection
system consists of the ECU and all the
sensors that provide it with information, plus
the actuators by which it controls the whole
system’s operation. The basic method of
operation is as follows; note that the ignition
system is controlled by the same ECU.
6The manifold absolute pressure sensor is
connected by a hose to the inlet manifold.
Variations in manifold pressure are converted
into graduated electrical signals that are usedby the ECU to determine the load on the
engine. The throttle valve potentiometer is
explained above.
7Information on engine speed and
crankshaft position comes from the distributor
on C16 NZ engines and from the crankshaft
speed/position sensor on C16 NZ2, X16 SZ
and C18 NZ engines.
8An odometer frequency sensor provides the
ECU with information on the vehicle’s road
speed, and the coolant temperature sensor
provides it with the engine temperature. A
knock sensor located in the cylinder block
between cylinders 2 and 3 on the X16 SZ
engine provides additional information to the
ECU by detecting pre-ignition (detonation)
during the combustion process.
9All these signals are compared by the ECU
with set values pre-programmed (mapped)
into its memory. Considering this information,
the ECU selects the response appropriate to
those values. It controls the ignition amplifier
module by varying the ignition timing as
required. The fuel injector is controlled by
varying its pulse width the time the injector is
held open, to provide a richer or weaker
mixture, as appropriate. The idle air control
stepper motor controls the idle speed. The
fuel pump relay controls the fuel delivery and
the oxygen sensor, accordingly. The mixture,
idle speed and ignition timing are constantly
varied by the ECU to provide the best settings
for cranking, starting and engine warm-up
(with either a hot or cold engine), idling,
4B•2Fuel and exhaust systems - fuel injection models