1988 OPEL VECTRA fuel tank removal

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

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.

4Unscrew the two securing bolts, and
withdraw the pump from the camshaft
housing (see illustration).
5Recover the plastic insulating block.
Refitting
6Refitting is a reversal of removal, but ensure
that the fuel hoses are reconnected to their
correct locations as noted during removal,
and tighten the securing bolts to the specified
torque.
7Run the engine and check for leaks on
completion. If leakage is evident, stop the
engine immediately and rectify the problem
without delay. Note that the engine may take
a longer time than usual to start when the
pump has been removed, as the pump refills
with fuel.
7Fuel tank - removal,
examination and refitting
4
Note: Refer to Section 2 before proceeding
Removal
1Disconnect the battery negative lead.
2Siphon out any remaining fuel in the tank
through the filler pipe. Siphon the fuel into a
clean metal container that can be sealed.
3Chock the front wheels, then jack up the
rear of the vehicle, and support securely on
axle stands (see “Jacking and Vehicle
Support”) placed under the body side
members.
4Disconnect the exhaust system front
flexible joint. Suspend the front section of the
exhaust system with wire or string from the
underbody.
5Disconnect the rear section of the exhaust
system from its rubber mountings, and allow it
to rest on the rear suspension torsion beam. It
is advisable to support the rear section of the
exhaust at its front end, with wire or string
from the underbody, to avoid straining the
system.
6Unclip the handbrake cable from the
bracket on the left-hand fuel tank securing
strap.
7Disconnect the fuel hoses from the fuel
level sender unit located in the right-hand side
of the fuel tank. Make a note of the hosepositions for use when refitting. Be prepared
for fuel spillage, and take adequate fire
precautions. Plug the open ends of the hoses,
to prevent dirt ingress and further fuel loss.
8Disconnect the wiring plug from the fuel
level sender unit.
9Disconnect the filler and vent hoses from
the rear of the fuel tank.
10Support the weight of the fuel tank on a
jack with an interposed block of wood.
11Unscrew the securing bolts from the tank
mounting straps, then remove the straps and
lower the tank sufficiently to enable the
disconnection of the remaining vent hose.
12With the aid of an assistant, withdraw the
tank sideways from the right-hand side of the
vehicle. Note that as the tank is withdrawn,
some residual fuel may be released.
Examination
13If the tank contains sediment or water, it
may be cleaned out using two or three rinses
with clean fuel. Shake vigorously using
several changes of fuel, but before doing so,
remove the fuel level sender unit, as
described in Section 8. This procedure should
be carried out in a well-ventilated area, and it
is vital to take adequate fire precautions -
refer to the “Safety first!” Section at the
beginning of this manual for further details.
14Any repairs to the fuel tank should be
carried out by a professional. Do not under
any circumstances attempt to weld or solder a
fuel tank. Removal of all residual fuel vapour
requires several hours of specialist cleaning.
Refitting
15Refitting is a reversal of removal, ensuring
that all hoses are reconnected to their correct
locations as noted during removal.
16On completion, fill the fuel tank, then run
the engine and check for leaks. If leakage is
evident, stop the engine immediately and
rectify the problem without delay. Note that
the engine may take a longer time than usual
to start when the fuel tank has been removed,
as the pump refills with fuel.
8Fuel level sender unit -
removal and refitting
3
Note: Refer to Section 2 before proceeding
Removal
1Disconnect the battery negative lead.
2Siphon out any remaining fuel in the tank
through the filler pipe. Siphon the fuel into a
clear metal container that can be sealed.
3Chock the front wheels, then jack up the rear
of the vehicle, and support securely on axle
stands (see “Jacking and Vehicle Support”)
placed under the body side members.
4The sender unit is located in the right-hand
side at the fuel tank.
5Make alignment marks on the sender unit
and the fuel tank, so that the sender unit can
be refitted in its original position.6Disconnect the fuel hoses from the sender
unit. Be prepared for fuel spillage, and take
adequate fire precautions. Plug the open ends
of the hoses, to prevent dirt ingress and
further fuel loss.
7Disconnect the wiring plug from the fuel
level sender unit.
8To remove the sender unit, engage a flat
piece of metal as a lever between two of the
slots on the sender unit rim, and turn it anti-
clockwise.
9Withdraw the unit carefully, to avoid
bending the float arm.
10Recover the sealing ring.
Refitting
11Refitting is a reversal of removal,
remembering the following points.
12Examine the condition of the sealing ring,
and renew if necessary.
13Ensure that the marks made on the
sender unit and fuel tank before removal are
aligned.
14Ensure that the hoses are reconnected to
their correct locations as noted during
removal.
15On completion, fill the fuel tank, then run
the engine and check for leaks. Also check
that the fuel gauge reads correctly. If leakage
is evident, stop the engine immediately and
rectify the problem without delay. Note that
the engine may take a longer time than usual
to start when the sender unit has been
removed, as the fuel pump refills with fuel.
9Fuel vapour separator (1.6
and 1.8 litre models) -
removal and refitting
3
Note: Refer to Section 2 before proceeding
Removal
1The fuel vapour separator is located on a
bracket attached to the side of the
carburettor.
2Note the locations of the three fuel hoses,
labelling them if necessary for use when
refitting, then disconnect the hoses from the
vapour separator. 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.
3Remove the two securing screws, and lift
the vapour separator from its bracket.
4Check the body of the separator for cracks
or leaks before refitting, and renew if
necessary.
Refitting
5Refitting is a reversal of removal, but ensure
that the three fuel hoses are connected to
their correct locations as noted during
removal.
6Run the engine and check the hose
connections for leaks on completion. If
leakage is evident, stop the engine
immediately and rectify the problem without
delay.
4A•4Fuel and exhaust systems - carburettor models
6.4 Withdrawing the fuel pump and plastic
insulating block - 1.6 litre model

Refitting
10Refitting is a reversal of removal.
Fuel and temperature gauge
assembly -“high series” models
11The procedure is as described in
paragraphs 7 to 10 inclusive, except that the
gauge assembly is secured by four nuts.
Tachometer
12The procedure is as described in
paragraphs 7 to 10 inclusive except that the
tachometer is secured by three nuts (see
illustration).
Speedometer
Removal
13Proceed as described in paragraphs 7
and 8.
14Extract the four securing screws from the
rear of the panel (see illustration).
Refitting
15Refitting is a reversal of removal.
Printed circuit board
Removal
16Remove all bulbs and instruments, and
the voltage stabiliser, as described previously
in this Section.
17Carefully peel the printed circuit board
from the instrument panel.
Refitting
18Refitting is a reversal of removal, but
ensure that the printed circuit board is seated
correctly on the rear of the instrument panel.
20Trip computer components -
removal and refitting
2
1Disconnect the battery lead.
Display module
Removal
2Using a thin-bladed screwdriver, carefully
prise the module from the facia panel.
3Disconnect the wiring plug and withdraw
the module.
Refitting
4Refitting is a reversal of removal.
Display module illumination bulb
Removal
5Remove the display module, as described
previously in this Section.
6Using a length of rubber sleeving of similar
diameter, or an alternator tool, extract the
bulb by inserting the tool through the hole in
the side of the display module (see
illustration).
Refitting
7Refitting is a reversal of removal.
Operating switch
Removal
8Remove the rear section of the centre
console, as described in Chapter 11.
9Release the wiring plug from the switch
using a screwdriver.
10Lift the switch, then pull it down and out
from the centre console.
Refitting
11Refitting is a reversal of removal.
Outside air temperature sensor
Removal
12The sensor is located at the left-hand end
of the front bumper (see illustration).
13Prise the cover cap from the bumper, then
unclip the sensor, and disconnect the wiring
plug.
Refitting
14Refitting is a reversal of removal.
21Check control system
components - removal and
refitting
3
1Disconnect the battery negative lead.
Warning lamp bulbs
2The warning lamp bulbs are located in the
instrument panel, and removal and refitting
are described in Section 19.
Control module
Removal
3The control module is located behind the
passenger side of the facia, above the
glovebox.
4Remove the glovebox assembly, as
described in Chapter 11.
5Disconnect the control module wiring plug,
then release the control module from its
mounting and withdraw the unit.
Refitting
6Refitting is a reversal of removal.
Coolant level sensor
Removal
7The coolant level sensor is integral with the
coolant expansion tank cap.
8Disconnect the wiring from the top of the
cap, then unscrew the cap and withdraw it
from the expansion tank.
9If faulty, the complete cap assembly must
be renewed.
Refitting
10Refitting is a reversal of removal.
Washer fluid level sensor
Removal
11The sensor is mounted in the side of the
fluid reservoir.
12Disconnect the wiring from the sensor,
then unscrew the sensor from the fluid
reservoir. If the fluid level is above the level of
the sensor, be prepared for fluid spillage.
Refitting
13Refitting is a reversal of removal.
Body electrical systems 12•7
20.6 Removing the trip computer display
module illumination bulb20.12 Trip computer outside air
temperature sensor location (arrowed)
19.14 Speedometer securing screws
(arrowed)19.12 Tachometer securing nuts (arrowed)
12

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

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

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

13Exhaust manifold - removal
and refitting
3
Note:New manifold-to-cylinder head, and
manifold-to-downpipe, gaskets must be used
on refitting. Exhaust manifolds on DOHC
models are of tubular design, which form part
of the front section of the exhaust.
Removal
1Disconnect the battery negative lead.
2Disconnect the HT leads from the spark
plugs, if necessary labelling them to ensure
refitting to the correct cylinders.
3Loosen the clamp screw and disconnect
the air cleaner hot air tube from the shroud on
the manifold, if fitted. Remove the securing
screws and withdraw the hot air shroud from
the manifold.
4Working under the manifold, unscrew and
remove the four bolts securing the exhaust
downpipe to the manifold.
5If fitted, disconnect the oxygen sensor
wiring
6Separate the downpipe from the manifold,
and support with wire or string. Do not allow
the front section of the exhaust system to hang
under its own weight. Recover the gasket.
7Unscrew the securing nuts, and withdraw
the manifold from the cylinder head (see
illustration). Recover the gasket.
8It is possible that some of the manifold
studs may be unscrewed from the cylinder
head when the manifold securing nuts are
unscrewed. In this event, the studs should be
screwed back into the cylinder head once the
manifold has been removed, using two
manifold nuts locked together.
Refitting
9Refit the manifold using a new gasket, and
tighten the securing nuts to the specified
torque.
10Reconnect the exhaust downpipe to the
manifold, using a new gasket and tighten the
securing bolts to the specified torque.
11Further refitting is a reversal of removal.
14Exhaust system - checking,
removal and refitting
2
Note: All relevant gaskets and/or sealing rings
should be renewed on refitting
Checking
1Periodically, the exhaust system should be
checked for signs of leaks or damage. Also
inspect the exhaust system rubber
mountings, and renew if necessary.
2Small holes or cracks can be repaired using
proprietary exhaust repair products, but
where more serious corrosion or damage is
evident, renewal will be necessary.
Removal
3The original factory-fitted exhaust system
consists of four separate sections, all of which
can be renewed individually.
4On models fitted with a catalytic converter,
an oxygen sensor is fitted to the front section
of the exhaust. The catalytic converter is fitted
in place of the front expansion box in the
conventional exhaust system. The
manufacturers do not specify any renewal
intervals for the catalytic converter.
5Before renewing an individual section of the
exhaust system, it is wise to inspect the
remaining sections. If corrosion or damage is
evident on more than one section of the
system, it may prove more economical to
renew the entire system.
6Individual sections of the exhaust system
can be removed as follows.
Front section - SOHC models
7On models with a catalytic converter,
disconnect the battery negative lead, and
disconnect the oxygen sensor wiring plug,
which is located behind the coolant expansion
tank.
8Raise the vehicle, and support securely on
axle stands placed under the body side
members (see “Jacking and Vehicle
Support”).
9Unscrew the two securing bolts, and
disconnect the exhaust front section from the
front expansion box or catalytic converter (as
applicable) at the flexible joint. Recover the
sealing ring and the springs (see illustration).10Unbolt the exhaust front section from the
bracket on the cylinder block (see
illustration).
11Unscrew and remove the four bolts
securing the downpipe to the exhaust
manifold, and withdraw the exhaust front
section (see illustration). Recover the
downpipe-to-manifold gasket.
Refitting
12Refitting is a reversal of removal, but use a
new gasket when reconnecting the downpipe
to the manifold, and a new sealing ring when
connecting the flexible joint. Tighten all fixings
to the specified torque.
Front section - DOHC models
Removal
13Proceed as described in paragraphs 7
and 8.
14Remove the engine undershield, as
described in Chapter 11.
15Proceed as described in paragraphs 9
and 10.
16Working in the engine compartment,
remove the bolts securing the exhaust
manifold heat shield to the cylinder head.
17Unscrew the two lower exhaust manifold
securing nuts that also secure the heat shield
brackets, and withdraw the heat shield (see
illustration).
18Unscrew the remaining manifold securing
nuts, then withdraw the manifold/exhaust
front section from the vehicle. Recover the
manifold gasket.
Fuel and exhaust systems - exhaust and emissions 4C•5
14.10 Exhaust front section support
bracket - SOHC models
14.11 Unscrewing a downpipe-to-exhaust
manifold bolt - SOHC models
14.9 Exhaust front section flexible joint -
SOHC models13.7 Unscrewing an exhaust manifold
securing nut - SOHC models
4C