fuel type OPEL VECTRA 1988 Service Repair Manual

4A
General
Fuel tank capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.0 litres
Fuel octane rating:
Leaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 RON (4-star)
Unleaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 RON (Premium)
Carburettor type (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pierburg 2E3
Air cleaner element
Application:
Round type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion W103
Square type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion U512
14 NV engine
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 925 ± 25 rpm
Idle mixture (CO content) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 to 1.5%
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2200 to 2600 rpm
Choke valve gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 to 3.5 mm
Choke pull-down gap:
“Small” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 to 2.1 mm
“Large” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 to 2.9 mm
Idle fuel jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Idle air bleed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Primary Secondary
Venturi diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.0 mm 24.0 mm
Main jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X95 X110
Chapter 4 Part A:
Fuel and exhaust systems - carburettor models
Accelerator pump - testing, removal and refitting . . . . . . . . . . . . . . .18
Air cleaner inlet air temperature control - description and testing . . . .4
Air cleaner - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Automatic choke unit - removal, refitting and adjustment . . . . . . . . .19
Automatic choke vacuum pull-down units - removal, refitting and
adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Carburettor - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Carburettor - removal, overhaul and refitting . . . . . . . . . . . . . . . . . . .13
Carburettor filter - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .21
Fuel level sender unit - removal and refitting . . . . . . . . . . . . . . . . . . . .8
Fuel pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Fuel pump - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Fuel system - precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Fuel tank - removal, examination and refitting . . . . . . . . . . . . . . . . . . .7
Fuel vapour separator (1.6 and 1.8 litre models) - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Idle cut-off solenoid (1.8 litre models) - description and testing . . . .25
Idle speed and mixture - adjustment . . . . . . . . . . . . . . . . . . . . . . . . .14
Idle speed increase valve - testing . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Inlet manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . .26
Needle valve and float - removal, inspection and refitting . . . . . . . . .15
Power valve diaphragm - removal and refitting . . . . . . . . . . . . . . . . .17
Secondary throttle valve vacuum diaphragm - testing, removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Throttle cable - removal, refitting and adjustment . . . . . . . . . . . . . . .11
Throttle pedal - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . .10
Throttle position sensor (automatic transmission models) - removal
and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Throttle valve dashpot (automatic transmission models) -
adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
4A•1
Specifications Contents
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

16 SV engine
Idle speed
Manual transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .925 ±25 rpm
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .825 ±25 rpm (in ‘park’ or ‘neutral’)
Idle mixture (CO content) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.5 to 1.5%
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2000 to 2400 rpm
Choke valve gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5 to 3.5 mm
Choke pull-down gap:
Up to 1990:
“Small” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.3 to 1.7 mm
“Large” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.9 to 2.3 mm
From 1990:
“Small” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5 to 1.7 mm
“Large” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.0 to 2.2 mm
Idle fuel jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Idle air bleed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132.5
PrimarySecondary
Venturi diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20.0 mm24.0 mm
Main jet:
Up to 1990 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .X95X105
From 1990 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .X92.5X105
18 SV engine
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .925 ±25 rpm
Idle mixture (CO content) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.5 to 1.5%
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1900 to 2300 rpm
Choke valve gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5 to 3.5 mm
Choke pull-down gap:
“Small” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.2 ±0.2 mm
“Large” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.3 ±0.2 mm
Idle fuel jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42.5
Idle air bleed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132.5
PrimarySecondary
Main jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107.5125
Torque wrench settingsNmlbf ft
Exhaust manifold nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2216
Exhaust downpipe-to-manifold bolts . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Exhaust fixings except flexible joint bolts . . . . . . . . . . . . . . . . . . . . . . . .2518
Exhaust flexible joint bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129
Fuel pump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1813
Fuel tank mounting strap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
Inlet manifold nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2216
1General description
The fuel system on all carburettor models
comprises a fuel tank, a fuel pump, a vapour
separator (1.6 and 1.8 litre models only), a
downdraught carburettor, and a thermostati-
cally-controlled air cleaner.
The fuel tank is mounted under the rear of
the vehicle, forward of the rear suspension.
The tank is ventilated to the atmosphere, and
has a simple filler pipe and a fuel gauge
sender unit.
The fuel pump is a mechanical diaphragm
type, actuated by a pushrod bearing on the
camshaft.
The fuel vapour separator is used to
stabilise the fuel supply to the carburettor.
Vapour is purged from the carburettor fuel
supply, thus improving hot starting qualities.
The carburettor is a Pierburg 2E3 type, a full
description of which is given in Section 12.The air cleaner has a wax or vacuum-
controlled air inlet supplying a blend of hot
and cold air to suit the prevailing engine
operating conditions. A fuller description is
given in Section 4.
All engines available within the Cavalier
range can be operated on unleaded petrol -
see Chapter 5.
2Fuel system - precautions
1Certain adjustment points in the fuel system
are protected by tamperproof caps, plugs or
seals. In some territories, it is an offence to
drive a vehicle with broken or missing
tamperproof seals. Before disturbing a
tamperproof seal, check that no local or
national laws will be broken by doing so, and
fit a new tamperproof seal after adjustment is
complete, where required by law. Do not
break tamperproof seals on a vehicle that is
still under warranty.2When working on fuel system components,
scrupulous cleanliness must be observed,
and care must be taken not to introduce any
foreign matter into fuel lines or components.
Carburettors in particular are delicate
instruments, and care should be taken not to
disturb any components unnecessarily.
Before attempting work on a carburettor,
ensure that the relevant spares are available.
Full overhaul procedures for carburettors have
not been given in this Chapter. Complete
stripdown of a carburettor is unlikely to cure a
fault that is not immediately obvious, without
introducing new problems. If persistent
problems are met, it is recommended that the
advice of a Vauxhall dealer or carburettor
specialist is sought. Most dealers will be able
to provide carburettor re-setting and servicing
facilities, and if necessary it should be
possible to buy a reconditioned carburettor.
3Refer to Chapter 5, for precautions to be
observed when working on vehicles fitted with
an engine management system.
4A•2Fuel and exhaust systems - carburettor models

3Air cleaner - removal and
refitting
2
Removal
1Remove the air cleaner element, as
described in Chapter 1.
2Release the crankcase ventilation hose
from the plastic clip on the left-hand side of
the air cleaner body.
3Disconnect the inlet duct from the hot air
hose on the exhaust manifold (see
illustration), and lift the air cleaner body from
the carburettor.
4With the body tilted to the rear, disconnect
the crankcase ventilation hose from the stub
on the underside of the body (see
illustration).Where applicable, disconnect
the vacuum hose from the air temperature
control flap thermostat.
5Remove the seal from under the air cleaner
body.
Refitting
6Check the hot air hose for condition, and
renew it if necessary.
7Fit a new air cleaner body-to-carburettor
seal.
8Connect the crankcase ventilation hose to
the stub on the underside of the body, and
connect the vacuum hose for the air
temperature control flap.
9Locate the body on the carburettor, and at
the same time locate the inlet duct on the hot
air hose on the exhaust manifold.
10Engage the crankshaft ventilation hose in
the plastic clip.
11Refit the air cleaner element, referring to
Chapter 1 if necessary.
4Air cleaner inlet air
temperature control -
description and testing
3
Description
1The air cleaner is thermostatically-
controlled, to provide air at the most suitable
temperature for combustion with minimum
exhaust emission levels.
2The optimum air temperature is achieved
by drawing in cold air from an inlet at the front
of the vehicle, and blending it with hot airdrawn from a shroud on the exhaust manifold.
The proportion of hot and cold air is varied by
the position of a flap valve in the air cleaner
inlet spout, which is controlled by either a
vacuum diaphragm or wax-type unit. The
vacuum diaphragm type is regulated by a heat
sensor located within the air cleaner body
(see illustration).
Testing
3To check the operation of the air
temperature control, the engine must be cold.
First check the position of the flap valve. On
the vacuum type, remove the air cleaner cover
and check that the flap is open to admit only
cold air from outside the car. Then start the
engine and check that the flap now moves to
admit only hot air from the exhaust manifold.
On the wax type, the flap should already be
positioned to admit only hot air from the
exhaust manifold.
4Temporarily refit the cover on the vacuum
type.
5Run the engine until it reaches its normal
operating temperature.
6On the vacuum type, remove the air cleaner
cover and check that the flap is now
positioned to admit only cold air from outside
the car. In cold weather it should be a mixture
of hot and cold air. Refit the cover after
making the check. On the wax type, use a
mirror to check that the flap is positioned in
the same way as given for the vacuum type.
7If the flap does not function correctly, the
air cleaner casing must be renewed. Note that
the vacuum type thermostat can be renewed
separately if necessary.
5Fuel pump - testing
2
Note: Refer to Section 2 before proceeding
1Disconnect the ignition coil LT lead.
2Place a clean piece of rag under the pump
outlet, then disconnect the pump outlet hose.
Be prepared for fuel spillage, and take
adequate fire precautions.
3Have an assistant crank the engine on the
starter. Well-defined spurts of fuel must be
ejected from the pump outlet - if not, the
pump is probably faulty (or the tank is empty).
Dispose of the fuel-soaked rag safely.
4No spare parts are available for the pump,
and if faulty, the unit must be renewed.
6Fuel pump - removal and
refitting
3
Note: Refer to Section 2 before proceeding
Removal
1The fuel pump is located at the rear right-
hand end of the camshaft housing.
2Disconnect the battery negative lead.
3Disconnect the fuel hoses from the pump
(see illustration). If necessary, label the
hoses so that they can be reconnected to
their correct locations. Be prepared for fuel
spillage, and take adequate fire precautions.
Plug the open ends of the hoses to prevent
dirt ingress and further fuel spillage.
Fuel and exhaust systems - carburettor models 4A•3
3.4 Disconnecting the crankcase
ventilation hose (arrowed)
6.3 Disconnecting a fuel hose from the
fuel pump - 1.6 litre model4.2 Air cleaner flap valve operating
mechanism
1 Flap valve 2 Operating rod
3.3 The air cleaner body locates over the
hot air hose
4A
Warning: Many of the
procedures given in this
Chapter involve the
disconnection of fuel pipes and
system components, which may result in
some fuel spillage. Before carrying out
any operation on the fuel system, refer to
the precautions given in the “Safety first!”
Section at the beginning of this manual
and follow them implicitly. Petrol is a
highly dangerous and volatile substance,
and the precautions necessary when
handling it cannot be overstressed.

10Throttle pedal - removal and
refitting
3
Removal
1Working inside the vehicle, remove the
lower trim panel from the driver’s footwell.
2Slide the cable retainer from the bracket on
the top of the pedal, and disconnect the cable
end from the pedal.
3Extract the circlip from the right-hand end
of the pedal pivot shaft, then slide out the
pivot shaft from the left-hand side of the pivot
bracket (see illustration). Recover the pivot
bushes and the pedal return spring.
4Examine the pivot bushes for wear, and
renew if necessary.
Refitting
5Refitting is a reversal of removal, but on
completion check the throttle mechanism for
satisfactory operation, and check the throttle
cable adjustment, as described in Section 11.
11Throttle cable - removal,
refitting and adjustment
3
Removal
1Remove the air cleaner, on early models.
On later models, disconnect the air trunking
from the air cleaner, then disconnect the
vacuum pipe and breather hose from the airbox. Extract the three securing screws and lift
off the air box, complete with air trunking(see
illustration).
2Extract the clip from the cable end fitting at
the bracket on the carburettor, then slide the
cable end grommet from the bracket (see
illustrations).
3Slide the cable end from the throttle valve
lever on the carburettor.
4Working inside the vehicle, remove the
lower trim panel from the driver’s footwell.
5Slide the cable retainer from the bracket on
the top of the pedal, and disconnect the cable
end from the pedal.
6Make a careful note of the cable routing,
then withdraw the cable through the bulkhead
into the engine compartment.Refitting
7Refitting is a reversal of removal,
remembering the following points.
8Ensure that the cable is correctly routed, as
noted before removal.
9Ensure that the bulkhead grommet is
correctly seated in its hole.
Adjustment
10On completion, check the throttle
mechanism for satisfactory operation, and if
necessary adjust the cable, as described in
the following paragraphs.
11Two points of cable adjustment are
provided. A stop screw is located on the
pedal arm to control the fully released position
of the pedal stop (see illustration).A clip is
located on a threaded section of the cable
sheath at the bracket on the carburettor, to
adjust the cable free play.12The cable should be adjusted so that
when the throttle pedal is released, there is
very slight free play in the cable at the
carburettor end.
13Check that when the throttle pedal is fully
depressed, the throttle valve is fully open.
Adjust the position of the clip on the cable
sheath, and the pedal stop screw, to achieve
the desired results.
12Carburettor - general
1The Pierburg 2E3 carburettor is of twin-
venturi, fixed-jet sequential throttle type. The
primary throttle valve operates alone except
at high engine speeds and loads, when the
secondary throttle valve is operated, until at
full-throttle, both are fully open. This
arrangement allows good fuel economy
during light acceleration and cruising, but also
gives maximum power at full-throttle. The
secondary throttle valve is vacuum-operated,
according to the vacuum produced in the
primary venturi. The primary throttle barrel
and venturi diameters are smaller than their
secondary counterparts. The carburettor is a
complicated instrument, with various
refinements and sub-systems added to
achieve improved driveability, economy and
exhaust emission levels(see illustrations).
Fuel and exhaust systems - carburettor models 4A•5
11.2A Extract the throttle cable end
clip . . .
12.1A Side view of carburettor, showing
accelerator pump (1) and main choke pull-
down diaphragm unit (2)11.11 Throttle pedal stop screw11.2B . . .and slide the grommet from the
bracket
11.1 Removing an air box securing screw10.3 Throttle pedal pivot assembly. Circlip
arrowed
4A

Distributor
Direction of rotor arm rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Anti-clockwise (viewed from cap)
Firing order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3-4-2 (No 1 cylinder at timing belt end of engine)
Dwell angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Automatically controlled by electronic module (not adjustable)
Ignition timing
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5°BTDC
16 SV, X 16 SZ, C 16 NZ, C 16 NZ2 and C 18 NZ . . . . . . . . . . . . . . . .10°BTDC *
18 SV and 2.0 litres models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 to 12°BTDC *
* Ignition timing electronically controlled no adjustment possible
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1 Specifications
Torque wrench settingNmlbf ft
Alternator mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Camshaft phase sensor disc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Camshaft phase sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1511
‘Compact’ series alternator lower mounting bolt . . . . . . . . . . . . . . . . . .3526
‘Compact’ series alternator upper mounting bolts . . . . . . . . . . . . . . . . .2015
DIS module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
Inductive pulse pick-up to block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Starter motor mounting bracket-to-cylinder block . . . . . . . . . . . . . . . . .2518
Starter motor mounting:
1.4 and 1.6 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
1.8 and 2.0 litre models:
Engine side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4533
Transmission side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7555
1Electrical system - general
1The electrical system is of the 12 volt
negative earth type, and consists of a 12 volt
battery, alternator with integral voltage
regulator, starter motor, and related electrical
accessories, components and wiring.
2The battery is of the maintenance-free
“sealed for life” type, and is charged by an
alternator, which is belt-driven from the
crankshaft pulley. The starter motor is of the
pre-engaged type, incorporating an integral
solenoid. On starting, the solenoid moves the
drive pinion into engagement with the flywheel
ring gear before the starter motor is
energised. Once the engine has started, a
one-way clutch prevents the motor armature
being driven by the engine until the pinion
disengages from the flywheel.
3It is necessary to take extra care when
working on the electrical system, to avoid
damage to semi-conductor devices (diodes
and transistors), and to avoid the risk of
personal injury. Along with the precautions
given in the “Safety first!” Section at the
beginning of this manual, take note of the
following points when working on the system.4Always remove rings, watches, etc. before
working on the electrical system. Even with
the battery disconnected, discharge could
occur if a component live terminal is earthed
through a metal object. This could cause a
shock or nasty burn.
5Do not reverse the battery connections.
Components such as the alternator, or any
other component having semi-conductor
circuitry, could be irreparably damaged.
6If the engine is being started using jump
leads and a slave battery, connect the
batteries positive to positive and negative to
negative. This also applies when connecting a
battery charger.
7Never disconnect the battery terminals, or
alternator multi-plug connector, when the
engine is running.
8The battery leads and alternator wiring
must be disconnected before carrying out any
electric welding on the vehicle.
9Never use an ohmmeter of the type
incorporating a hand-cranked generator for
circuit or continuity testing.
2Ignition system - general
1The ignition system is responsible for
igniting the air/fuel mixture in each cylinder at
the correct moment, in relation to engine
speed and load. A number of different types
of ignition systems are fitted to models within
the range. Ranging from a basic breakerless
electronic system, to a fully integrated engine
management system controlling both ignition
and fuel injection systems. Each system isdescribed in further detail later in this Section.
2The ignition system is based on feeding low
tension voltage from the battery to the coil,
where it is converted to high tension voltage.
The high tension voltage is powerful enough
to jump the spark plug gap in the cylinders
many times a second under high compression
pressures, providing that the system is in
good condition. The low tension (or primary)
circuit consists of the battery, the lead to the
ignition switch. The lead from the ignition
switch to the low tension coil windings and
the supply terminal on the electronic module.
The lead from the low tension coil windings to
the control terminal on the electronic module.
The high tension (or secondary) circuit
consists of the high tension coil windings, the
HT (high tension) lead from the coil to the
distributor cap, the rotor arm, the HT leads to
the spark plugs, and the spark plugs.
3The system functions in the following
manner. Current flowing through the low
tension coil windings produces a magnetic
field around the high tension windings. As the
engine rotates, a sensor produces an
electrical impulse that is amplified in the
electronic module and used to switch off the
low tension circuit.
4The subsequent collapse of the magnetic
field over the high tension windings produces
a high tension voltage, which is then fed to the
relevant spark plug through the distributor
cap and rotor arm. The low tension circuit is
automatically switched on again by the
electronic module, to allow the magnetic field
to build up again before the firing of the next
spark plug. The ignition is advanced and
retarded automatically, to ensure that the
spark occurs at the correct instant with the
engine speed and load.
5•2Engine electrical systems
Caution: Before carrying out
any work on the vehicle
electrical system, read through
the precautions given in the
“Safety first!” Section at the beginning of
this manual, and in Section 3 of this
Chapter.

28The system also incorporates a separate
ignition amplifier module that transmits
amplified signals from the main system
module to trigger the HT pulse from the
ignition coil. The module is mounted on the
ignition coil’s bracket/baseplate.
29Additionally, the Motronic module
receives information from a cylinder
block-mounted knock sensor, which senses
“knocking” (or pre-ignition) just as it begins to
occur, enabling the module to retard the
ignition timing, thus preventing engine
damage.
Simtec 56.1
30This system uses increased amount of
electronic components instead of mechanical
parts as sensors and actuators with the
Simtec engine management system. This
provides more precise operating data as well
as greater problem free motoring.
31The control unit is equipped with
electronic ignition control. Called ‘Micropro-
cessor Spark Timing System, inductive
triggered’, (or MSTS-i), and means that the
mechanical high voltage distributor is no
longer needed. It is located behind the trim
panel, on the right-hand side footwell (door
pillar).
32The ignition coil is replaced by a dual
spark ignition coil, which is switched directly
by the output stages in the control unit.
33A camshaft sensor will maintain
emergency operation, should the crankshaft
inductive pulse pick-up, malfunction. These
sense TDC (‘Top Dead Centre’), crankshaft
angle and engine speed. The signals are used
by the control unit to calculate ignition point
and for fuel injection.
34The ‘hot film airflow meter’ determines the
mass of air taken in by the engine. The system
uses this information to calculate the correct
amount of fuel needed for injection in the
engine.
35The air inlet temperature sensor (NTC), is
fitted in the air inlet duct between the air
cleaner and the hot mass air flow meter.
36A controlled canister purge valve is
actuated by the system. The tank ventilation is
monitored closely with the Lambda control (or
oxygen sensor) and adaptation by the
computer within the control unit.
37A knock control system is also fitted. This
eliminates the need for octane number
adjustment, as it is performed automatically
through the control unit.
3Electrical system -
precautions
1It is necessary to take extra care when
working on the electrical system, to avoid
damage to semi-conductor devices (diodes
and transistors), and to avoid the risk of
personal injury. Along with the precautions
given in the “Safety first!” Section at the
beginning of this manual, take note of the
following points when working on the system.
2Always remove rings, watches, etc. before
working on the electrical system. Even with
the battery disconnected, discharge could
occur if a component live terminal is earthed
through a metal object. This could cause a
shock or nasty burn.
3Do not reverse the battery connections.
Components such as the alternator, or any
other component having semi-conductor
circuitry, could be irreparably damaged.
4If the engine is being started using jump
leads and a slave battery, connect the
batteries positive to positive and negative to
negative. This also applies when connecting a
battery charger.
5Never disconnect the battery terminals, or
alternator multi-plug connector, when the
engine is running.
6The battery leads and alternator wiring
must be disconnected before carrying out any
electric welding on the vehicle.
7Never use an ohmmeter of the type
incorporating a hand-cranked generator for
circuit or continuity testing.
8Engine management modules are very
sensitive components, and certain
precautions must be taken, to avoid damage
to the module when working on a vehicle
equipped with an engine management
system, as follows.
9When carrying out welding operations on
the vehicle using electric welding equipment,
the battery and alternator should be
disconnected.
10Although underbonnet-mounted modules
will tolerate normal underbonnet conditions,
they can be adversely affected by excess heat
or moisture. If using welding equipment or
pressure washing equipment near the
module, take care not to direct heat, or jets of
water or steam, at the module. If this cannot
be avoided, remove the module from the
vehicle, and protect its wiring plug with a
plastic bag.
11Before disconnecting any wiring, or
removing components, always ensure that the
ignition is switched off.
12Do not attempt to improvise fault
diagnosis procedures using a test lamp or
multimeter, as irreparable damage could be
caused to the module.13After working on ignition/engine
management system components, ensure
that all wiring is correctly reconnected before
reconnecting the battery or switching on the
ignition.
14Any ignition system that uses a
“Hall-effect” generator in the distributor,
cannot be tested. Test equipment that uses
its own power source (e.g. an ohmmeter),
when connected to the distributor or the
“Hall-effect” generator, will be damaged.
4Ignition system testing -
general
3
Note: Refer to Section 3 before proceeding.
Always switch off the ignition before
disconnecting or connecting any component
and when using a multi-meter to check
resistances. Any voltmeter or multi-meter
used to test ignition system components must
have an impedance of 10 meg ohms or
greater
1Electronic ignition system components are
normally very reliable. Most faults are far more
likely to be due to loose or dirty connections,
or to “tracking” of HT voltage due to dirt,
dampness or damaged insulation than to
component failure. Always check all wiring
thoroughly before condemning an electrical
component and work methodically to
eliminate all other possibilities before deciding
that a particular component is faulty.
2The old practice of checking for a spark by
holding the live end of a HT lead a short
distance away from the engine is not
recommended. Not only is there a high risk of
a powerful electric shock, but the ignition coil
or amplifier module will be damaged.
Similarly, never try to “diagnose” misfires by
pulling off one HT lead at a time. Note also
that the ECU is at risk if the system is
triggered with an open (i.e., not properly
earthed) HT circuit; ECU’s are very expensive
to replace, so take care!
3If you are in any doubt as to your skill and
ability to test an ignition system component or
if you do not have the required equipment,
take the vehicle to a suitably equipped
Vauxhall dealer. It is better to pay the labour
charges involved in having the vehicle
checked by an expert than to risk damage to
the system or to yourself.
4If the engine either will not turn over at all,
or only turns very slowly, check the battery
and starter motor. Connect a voltmeter across
the battery terminals (meter positive probe to
battery positive terminal) and disconnect the
ignition coil HT lead from the distributor cap
and earth. Note the voltage reading obtained
while turning over the engine on the starter for
(no more than) ten seconds. If the reading
obtained is less than approximately 9.5 volts,
check the battery, battery connections, starter
motor and charging system.
5•4Engine electrical systems
Warning: The HT voltage
generated by an electronic
ignition system is extremely
high and, in certain
circumstances, could prove fatal. Take
care to avoid receiving electric shocks
from the HT side of the ignition system.
Do not handle HT leads, or touch the
distributor or coil, when the engine is
running. If tracing faults in the HT circuit,
use well-insulated tools to manipulate live
leads

5If the engine turns over at normal speed but
will not start, check the HT circuit by
connecting a timing light and turning the
engine over on the starter motor. If the light
flashes, voltage is reaching the spark plugs,
so these should be checked first. If the light
does not flash, check the HT leads
themselves followed by the distributor cap,
carbon brush and rotor arm.
6If there is a spark, check the fuel system for
faults as far as possible (Chapters 4A or 4B).
7If there is still no spark, check the voltage at
the ignition coil “+” or “15” terminal; it should
be the same as the battery voltage (i.e., at
least 11.7 volts). If the voltage at the coil is
more than 1 volt less than that at the battery,
check the connections back through the
ignition switch to the battery and its earth until
the fault is found. Note, however, that the
ECU controls the coil’s feed; do not attempt
to “test” the ECU with anything other than the
correct test equipment, which will be available
only to a Vauxhall dealer. If any of the wires
are to be checked which lead to the ECU,
always first unplug the relevant connector
from the ECU so that there is no risk of the
ECU being damaged by the application of
incorrect voltages from test equipment.
8If the feed to the ignition coil is sound,
check the coil’s primary and secondary
windings (refer to Section 16). Renew the coil
if faulty, but check the condition of the LT
connections themselves before doing so, to
ensure that the fault is not due to dirty or
poorly fastened connectors.
9If the ignition coil is in good condition, the
fault may be within the amplifier module or the
distributor on the C16 NZ and C16 NZ2
engines, or the amplifier or the crankshaft
speed/position sensor on the C18 NZ engine.
A quick check of these components can be
made by connecting a low-wattage bulb
across the ignition coil’s (disconnected) LT
terminals. If the bulb flickers or flashes when
the engine is turned over, the amplifier and
distributor (C16 NZ and C16 NZ2 engines), or
amplifier and crankshaft speed/position
sensor (C18 NZ engine), are sound.
10If this is the case, the entire LT circuit is in
good condition; the fault, if it lies in the
ignition system, must be in the HT circuit
components. These should be checked
carefully, as outlined above.
11If the indicator or bulb does not flash, the
fault is in either the amplifier or the distributor
(C16 NZ and C16 NZ2 engines), or the
amplifier or crankshaft speed/position sensor
(C18 NZ engine). Owners should note,
however, that by far the commonest cause of
“failure” of either of these is a poor
connection, either between the components
themselves or in the LT circuit wiring
connections. If such a fault is suspected, the
vehicle must be taken to a suitably equipped
Vauxhall dealer for testing; no information is
available to eliminate these components by
other means.12An irregular misfire suggests either a
loose connection or intermittent fault on the
primary circuit, or a HT fault on the coil side of
the rotor arm.
13With the ignition switched off, check
carefully through the system ensuring that all
connections are clean and securely fastened.
If the equipment is available, check the LT
circuit as described in paragraphs 7 to 11
above.
14Check that the HT coil, the distributor cap
and the HT leads are clean and dry. Check the
leads and the spark plugs (by substitution, if
necessary), then check the distributor cap,
carbon brush and rotor arm.
15Regular misfiring is almost certainly due to
a fault in the distributor cap, HT leads or spark
plugs. Use a timing light (paragraph 5, above)
to check whether HT voltage is present at all
leads.
16If HT voltage is not present on any
particular lead, the fault will be in that lead or
in the distributor cap. If HT is present on all
leads, the fault will be in the spark plugs;
check and renew them if there is any doubt
about their condition.
17If no HT voltage is present, check the
ignition coil; its secondary windings may be
breaking down under load.
18If all components have been checked for
signs of obvious faults but the system is still
thought to be faulty, take the vehicle to a
Vauxhall dealer for testing on special
equipment.
5Battery - testing and charging
2
Note: Refer to Section 3 before proceeding.
Testing
1Topping-up and testing of the electrolyte in
each cell is not possible. The condition of the
battery can therefore only be tested by
observing the battery condition indicator.
2The battery condition indicator is fitted in
the top of the battery casing, and indicates
the condition of the battery from its colour. If
the indicator shows green, then the battery is
in a good state of charge. If the indicator turns
darker, eventually to black, then the battery
requires charging, as described later in this
Section. If the indicator shows clear/yellow,
then the electrolyte level in the battery is too
low to allow further use, and the battery
should be renewed.
Charging
3Do not attempt to charge, load or jump start
a battery when the indicator shows
clear/yellow. If the battery is to be charged,
remove it from the vehicle and charge it as
follows.
4The maintenance-free type battery takes
considerably longer to fully recharge than the
standard type, the time taken being
dependent on the extent of discharge.5A constant-voltage type charger is required,
to be set, when connected, to 13.9 to 14.9
volts with a charger current below 25 amps.
6If the battery is to be charged from a fully
discharged state (less than 12.2 volts output),
have it recharged by a Vauxhall dealer or
battery specialist, as the charge rate will be
high and constant supervision during charging
is necessary.
6Battery - removal and refitting
2
Note: Refer to Section 3 before proceeding.
Removal
1The battery is located at the left-hand front
corner of the engine compartment.
2Disconnect the lead(s) at the negative
(earth) terminal by unscrewing the retaining
nut and removing the terminal clamp.
3Disconnect the positive terminal lead(s) in
the same way.
4Unscrew the clamp bolt sufficiently to
enable the battery to be lifted from its
location. Keep the battery in an upright
position, to avoid spilling electrolyte on the
bodywork.
Refitting
5Refitting is a reversal of removal, but smear
petroleum jelly on the terminals when
reconnecting the leads, and always connect
the positive lead first and the negative lead
last.
7Alternator - description
1A Delco-Remy or Bosch alternator may be
fitted, depending on model and engine
capacity. The maximum output of the
alternator varies accordingly.
2The alternator is belt-driven from the
crankshaft pulley. Cooling is provided by a
fan, mounted outside the casing on the end of
the rotor shaft. An integral voltage regulator is
incorporated, to control the output voltage.
3The alternator provides a charge to the
battery even at very low engine speed, and
consists of a coil-wound stator in which a
rotor rotates. The rotor shaft is supported in
ball-bearings, and slip rings are used to
conduct current to and from the field coils
through the carbon brushes.
4The alternator generates ac (alternating
current), which is rectified by an internal diode
circuit to dc (direct current) for supply to the
battery.
5Later models are fitted with a Delco-Remy,
‘compact’ series alternators (see illustration).
They use a ribbed V-belt type drivebelt with
automatic tensioner. They are rigidly mounted
to the engine.
Engine electrical systems 5•5
5

in a clip at the left-hand rear of the engine
compartment (see illustration).
4The plug is reversible in its connector, and
is marked either “A” or “98” on one side,
which corresponds to the position for use with
98 RON leaded petrol. On the other side either
“B” or “95”, which corresponds to the position
to use with 95 RON unleaded petrol. All
vehicles are set for use with 95 RON unleaded
petrol before they leave the factory.
5To change the coding for use with a
different type of petrol, first allow the fuel tank
to become practically empty.
6Fill the fuel tank with the required type of
petrol.
7Ensure that the ignition is switched off, then
remove the coding plug from its clip and
disconnect the wiring connector.
8Rotate the plug through 180°, so that the
appropriate octane mark is uppermost (see
paragraph 4), then reconnect the wiring
connector and refit the plug to its clip.
9Note that using petrol with a higher octane
rating than that set will not cause damage, but
petrol with a lower octane rating than that set
must not be used.
20 XE, C20 XE and X20 XEV
models
10The ignition coding plug found on these
models is not an octane coding plug
(although its method of operation is similar)
and must not be altered from its factory
setting. Its purpose is to ensure that the
Motronic module uses the correct information,
pre-programmed (or “mapped”) into its
memory, to enable the vehicle to comply with
the relevant national noise and exhaust
emission legislation.
11On these models, the knock sensor circuit
allows the Motronic module to compensate
for differences in the octane value of the
petrol used, without the need for manual
intervention. Remember, however, that all
catalytic converter-equipped vehicles must
use unleaded petrol only. This means that
these models can use any grade of unleaded
petrol on sale in the UK without the need for
adjustment.
23Electronic modules - removal
and refitting
3
Note: Refer to Section 3 for precautions to be
observed when working with electronic
modules. Heat sink compound must be used
when refitting the module.
HEI module (14 NV models)
Removal
1The module is mounted on a metal plate,
beneath the ignition coil, on the left-hand side
of the engine compartment.
2Remove the ignition coil as described in
Section 16, and slide the coil from its clamp.
3The module can be removed from the
mounting plate by unscrewing the two
securing screws.
4Before refitting the module, heat sink
compound should be applied to the mounting
plate to improve heat dissipation. If a new
module is being fitted, it should be supplied
with heat sink compound. Similar compounds
can be bought from DIY electrical shops.
Refitting
5Refitting is a reversal of removal.
MSTS-i module (1.6 and 1.8 litre
models)
Removal
6The module is mounted on the engine
compartment bulkhead, above the steering
rack (see illustration).
7Disconnect the battery negative lead.
8If desired, for improved access, remove the
air box from the top of the carburettor.
9Disconnect the wiring plug from the
module.
10Unscrew the two securing nuts, and
withdraw the module from the bulkhead.
Refitting
11Refitting is a reversal of removal.
Motronic module
Removal
12The module is mounted in the driver’s
footwell, behind the side trim panel.13Disconnect the battery negative lead.
14Remove the driver’s footwell side trim
panel, as described in Chapter 11.
15Unscrew the three module securing
screws, two at the top of the module, and a
single screw at the bottom, and lower the
module from the footwell (see illustration).
16Release the retaining clip, and disconnect
the module wiring plug (see illustration).
17Withdraw the module, noting the plastic
insulating sheet on its rear face.
Refitting
18Refitting is a reversal of removal, but
ensure that the insulating sheet is in place on
the rear face of the module.
24MSTS-i components -
removal and refitting
3
Note: Refer to Section 3 before proceeding.
Procedures for removal and refitting of the
ignition system components and electronic
module are given elsewhere in the relevant
Sections of this Chapter
Manifold pressure sensor
Removal
1The sensor is located on the engine
compartment bulkhead, to the left of the
MSTS-i module, under the edge of the
windscreen cowl panel (see illustration).
2Disconnect the battery negative lead.
5•14Engine electrical systems
22.3 Octane coding plug (arrowed) -
2.0 litre model
23.15 Lowering the Motronic module from
the footwell - 2.0 litre model23.16 Releasing the Motronic module
wiring plug clip - 2.0 litre model
23.6 MSTS-i module location -
1.6 litre model

4The cut-off valve can now be removed from
the bracket.
Testing
5To test the cut-off valve a vacuum hand
pump with gauge will be required. If available,
connect to the cut-off valve and ensure that
air through-flow aperture is fully open.
Refitting
6Refitting is a reversal of removal. Ensure
valve is fitted in the correct direction.
8AIR switchover valve -
removal and refitting
3
Removal
1Disconnect the battery negative lead.
2Disconnect wiring plug from the valve.
3Mark the location of the vacuum hoses
before removing them from the valve.
4After disconnecting the hoses undo the two
bolts, and remove them from its bracket.
Refitting
5Refitting is a reversal of removal. Ensure
hoses are fitted correctly (see illustration).
9AIR pipe and non-return
valve - removal and refitting
3
Note:New air pipe washers will be required
when refitting.
Removal
1Remove the non-return valve air duct hose.
2Undo the bolts engine lifting eye bracket,
and turn the bracket on to its left hand side.
3Remove the pipe support bracket by
releasing its three bolts.
4Remove the heat shield that is secured by
two bolts.
5The air pipe can now be removed by
releasing the two securing bolts.
6If necessary the non-return valve can now
be disconnected.
7Carefully clamp the pipe using a vice with
protective jaws. Unbolt the valve from the
pipe, clean and inspect for damage.
Refitting
8Before refitting, coat the threads of the non-
return valve with sealing compound (i.e.
Vauxhall part no. 90094714).
9Use new washers when refitting the pipe,
(take care as the washers have sharp edges).
Coat the pipe mounting bolts with assembly
paste (i.e. Vauxhall part no. 90513210), before
refitting.
10Refitting is a reversal of removal.
Retighten to correct torque as shown in Spec-
ifications.
10Catalytic converter -
description, general and
precautions
Note: The catalytic converter is not a filter. It
creates a chemical reaction, but it is not
affected by that reaction.
Description
1Certain models are available with a catalytic
converter, to reduce exhaust emissions.
These models can be identified by a ‘C’ or ‘X’,
prefixing the engine code.
2The purpose of the catalytic converter is to
change potentially harmful hydrocarbon andcarbon monoxide exhaust gases into harmless
gases and water vapour. The converter
consists of a stainless steel canister containing
a catalyst-coated honeycomb ceramic. The
catalyst is a mixture of three precious metals,
platinum, palladium and rhodium.
3The exhaust gases pass freely through the
honeycomb, where the catalyst speeds up the
chemical change of the exhaust gases,
without being permanently altered itself.
4To avoid damage to the catalyst, the engine
must be kept properly tuned, and unleaded
petrol must always be used. Normal leaded
petrol will “poison” the catalyst, and must not
be used.
5To enable the Motronic engine management
system to achieve complete combustion of the
fuel mixture, and thus to minimise exhaust
emissions, an oxygen sensor is fitted in the
exhaust gas stream. The sensor monitors the
oxygen level in the exhaust gas, and sends a
signal to the Motronic module. The module
constantly alters the fuel/air mixture within a
narrow band to reduce emissions, and to allow
the catalytic converter to operate at maximum
efficiency. No adjustment of idle mixture is
therefore possible on models fitted with a
catalytic converter.
General
6Ninety-nine per cent of exhaust gases, from
a petrol engine (however efficient or well
tuned), consists of nitrogen (N
2), carbon
dioxide (CO
2), oxygen (O2), other inert gases
and water vapour (H
2O). The remaining 1% is
made up of the noxious materials that are
currently seen (except CO
2), as the major
polluters of the environment. Carbon
monoxide (CO), unburned hydrocarbons (HC),
oxides of nitrogen (NOx) and some solid
matter, including a small lead content.
7The device most commonly used to clean
up vehicle exhausts is the catalytic converter.
It is fitted into the vehicle’s exhaust system
and uses precious metals (platinum and
palladium or rhodium) as catalysts to speed
up the reaction between the pollutants and
the oxygen in the exhaust gases. CO and HC
being oxidised to form H
2O and CO2and (in
the three-way type of catalytic converter) NOx
being reduced to N
2.
8The converter consists of an element of
ceramic honeycomb, coated with a
combination of precious metals in such a way
as to produce a vast surface area over which
the exhaust gases must flow. The three-way
closed-loop type converter fitted to these
models can remove over 90% of pollutants.
9The catalytic converter is a reliable and
simple device that needs no maintenance.
However there are some facts that an owner
should be aware if the converter is to function
properly for its full service life (see
illustration).
a)DO NOT use leaded petrol in a vehicle
equipped with a catalytic converter. The
lead will coat the precious metals,
reducing their converting efficiency and
will eventually destroy the converter.
Fuel and exhaust systems - exhaust and emissions 4C•3
10.9 The catalytic converter is protected
by heat shields
8.5 AIR switchover valve
1 Connection to brake servo vacuum hose
2 Connection to cut-off valve
7.1 AIR cut-off valve
1 Connection to AIR pump
2 Connection to AIR switchover valve
3 Connection to AIR non-return valve
4C

4B
General
Injection system type:
C16 NZ, C16 NZ2, X16 SZ and C18 NZ . . . . . . . . . . . . . . . . . . . . . . . Multec Central Fuel Injection
20 NE, C20 NE and 20 SEH, (up to 1990) . . . . . . . . . . . . . . . . . . . . . Motronic M4.1
20 NE, C20 NE and 20 SEH, (from 1990) . . . . . . . . . . . . . . . . . . . . . . Motronic M1.5
20 XEJ and C20 XE, (up to 1993) . . . . . . . . . . . . . . . . . . . . . . . . . . . . Motronic M2.5
C20 XE (from 1993) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Motronic M2.8
X20 XEV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simtec 56.1
Fuel tank capacity:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.0 ± 2 litres
Fuel octane rating *
Leaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 RON (4-star)
Unleaded (refer to Chapter 5) * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 RON (Premium)
* Note
: Models fitted with a catalytic converter (engine code prefixed by ‘C’ or ‘X’), must only be operated on unleadedfuel.
Idle settings
Idle speed:
C16 NZ and X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 850 ± 80 rpm
C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 880 ± 80 rpm
C18 NZ
Manual transmission models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 880 ± 80 rpm
Automatic transmission models . . . . . . . . . . . . . . . . . . . . . . . . . . . 830 ± 80 rpm
20 NE, C20 NE and 20 SEH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800 ± 80 rpm
20 XEJ and C20 XE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 940 ± 80 rpm
X20 XEV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 850 ± 160 rpm
Note:Idle speed adjustment is not possible on these models, for information only
Chapter 4 Part B:
Fuel and exhaust systems - fuel injection models
Air box - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Air cleaner - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Air filter element - renewal . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Airflow meter (if fitted) - removal and refitting . . . . . . . . . . . . . . . . . .25
Air mass meter (if fitted) - removal and refitting . . . . . . . . . . . . . . . . .26
Air temperature sensor (later models) - removal and refitting . . . . . . .7
Air temperature control - description and testing . . . . . . . . . . . . . . . .6
Depressurising the fuel system - general . . . . . . . . . . . . . . . . . . . . . . .8
Electronic Control Unit (ECU) - removal and refitting . . . . . . . . . . . . .35
Fuel filter (‘In-tank’ fuel pump models) - removal and refitting . . . . . .10
Fuel filter (‘Out-of-tank’ fuel pump models) - removal and refitting . . .9
Fuel flow damper - removal and refitting . . . . . . . . . . . . . . . . . . . . . .18
Fuel injection system - precautions . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Fuel injector (Multec system) - removal and refitting . . . . . . . . . . . . .29
Fuel injector (Multec system) - testing . . . . . . . . . . . . . . . . . . . . . . . .30
Fuel injectors (except Multec system) - removal and refitting . . . . . .28
Fuel pressure regulator - removal and refitting . . . . . . . . . . . . . . . . .21
Fuel pump - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Fuel pump (‘In-tank’ fuel pump models) - removal and refitting . . . .13
Fuel pump (‘Out-of-tank’ fuel pump models) - removal and refitting .12
Fuel pump relay - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14Fuel tank - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Fuel tank filler pipe - removal and refitting . . . . . . . . . . . . . . . . . . . . .15
Fuel tank sender unit - removal and refitting . . . . . . . . . . . . . . . . . . .17
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Hot film mass airflow meter - removal and refitting . . . . . . . . . . . . . .27
Idle air control stepper motor - removal and refitting . . . . . . . . . . . . .33
Idle mixture - checking and adjustment . . . . . . . . . . . . . . . . . . . . . . .20
Idle speed adjuster - removal and refitting . . . . . . . . . . . . . . . . . . . . .22
Inlet manifold (DOHC models) - removal and refitting . . . . . . . . . . . .40
Inlet manifold (SOHC with Multec) - removal and refitting . . . . . . . . .39
Inlet manifold (SOHC without Multec) - removal and refitting . . . . . .38
Knock sensor and module (X16 SZ models) - removal and refitting .36
Knock sensor (Simtec system) - removal and refitting . . . . . . . . . . . .37
System testing - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Throttle body (except Multec system) - removal and refitting . . . . . .31
Throttle body (Multec system) - removal and refitting . . . . . . . . . . . .32
Throttle cable - removal, refitting and adjustment . . . . . . . . . . . . . . .19
Throttle pedal - removal and refitting . . . . . . . . . . . . . .See Chapter 4A
Throttle position sensor - removal and refitting . . . . . . . . . . . . . . . . .23
Throttle potentiometer - removal and refitting . . . . . . . . . . . . . . . . . .34
Throttle valve potentiometer - removal and refitting . . . . . . . . . . . . .24
4B•1
Specifications Contents
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