coolant reservoir OPEL CALIBRA 1988 Service Repair Manual

underside. If the distance measured exceeds,
or is less than, that specified, the float weight
is incorrect and the float must be renewed.
12When the float level is known to be
correct, reassemble the carburettor, using a
new top cover gasket. Check the idle speed
and mixture settings as described in Section
14.
13Using a pin punch, tap the float retaining
pin from the base of the top cover, and lift out
the float and needle valve.
14Inspect the components for damage, and
renew as necessary. Check the needle valve
for wear, and check the float for leaks by
shaking it to see if it contains petrol.
15Clean the mating faces of the carburettor
body and top cover.
Refitting
16Refitting is a reversal of removal,
remembering the following points.
17After refitting, check the float and needle
valve for full and free movement.
18Use a new gasket between the top cover
and the carburettor body.
19Ensure that all hoses, pipes and wires are
correctly reconnected.
20On completion, check and if necessary
top-up the coolant level, as described in
Chapter 3, and check and if necessary adjust
the idle speed and mixture, as described in
Section 14.
16Secondary throttle valve
vacuum diaphragm - testing,
removal and refitting
3
Note: The diaphragm unit must be renewed in
its entirety, as no spares are available
Testing
1If a vacuum source incorporating a gauge is
available, apply approximately 300 mbars (9 in
Hg) to the diaphragm unit, at the hose nearest
the carburettor body. Close off the vacuum
source, and check that the vacuum is held. If
there is a leak, rectify or renew the leaking
component. Alternately, testing of a suspect
vacuum unit must be by the substitution of a
known good item.
Removal
2Remove the air cleaner, on early models.
On later models, disconnect the air trunking
from the air cleaner, then disconnect the
vacuum pipe air breather hose from the air
box. Extract the three securing screws and lift
off the air box, complete with air trunking.
3Disconnect the vacuum pipe from the
diaphragm unit.
4Prise the diaphragm operating rod balljoint
from the secondary throttle valve linkage.
5On 1.6 and 1.8 litre models, remove the two
securing screws and lift the vapour separator
from the bracket. Move the vapour separator
to one side, taking care not to strain the fuel
hoses.6Remove the three securing screws, and
withdraw the diaphragm unit complete with its
bracket from the carburettor body.
Refitting
7Refitting is a reversal of removal.
17Power valve diaphragm -
removal and refitting
3
Note: Refer to Section 2 before proceeding
Removal
1Disconnect the battery negative lead.
2Remove 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.
3Thoroughly clean all external dirt from the
area around the power valve housing.
4Remove the two securing screws, and lift
off the power valve cover, spring, and
diaphragm assembly.
Refitting
5Clean the mating faces of the cover and
housing.
6Locate the spring on the cover and
diaphragm assembly, ensuring that it is
correctly seated, then press the diaphragm
assembly and cover together. Note that the
vacuum hole in the diaphragm must align with
the corresponding holes in the housing flange
and cover.
7Further refitting is a reversal of removal, but
ensure that the diaphragm is correctly seated
(see illustration).
18Accelerator pump - testing,
removal and refitting
3
Note: Refer to Section 2 before proceeding
Testing
1It will be necessary to feed the float
chamber with fuel from a small reservoir
during this test.
2Position the primary barrel over an accurate
measuring glass. Fully open and close the
throttle ten times, taking approximately one
second for each opening, and pausing for
three seconds after each return stroke. Make
sure that the fast idle cam is not restricting
throttle travel at either end.
3Measure the quantity of fuel delivered, and
compare this with the specified value.
4A•8Fuel and exhaust systems - carburettor models
15.11 Measuring the float level “X”
17.7 Carburettor power valve components
1 Cover
2 Spring3 Diaphragm
assembly

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

Brake fluid level sensor
14The procedure is as described for the
coolant level sensor in paragraphs 7 to 10
inclusive.
Engine oil level sensor
Removal
15Apply the handbrake, jack up the front of
the vehicle, and support securely on axle
stands (see “Jacking and Vehicle Support”)
positioned under the body side members.
16On DOHC models, remove the engine
undershield, as described in Chapter 11.
17Disconnect the sensor wiring plug.
18Unscrew the three or four sensor securing
screws, as applicable, and withdraw the
sensor, manipulating the float through the hole
in the sump (see illustration). Recover the
sealing ring. Be prepared for some oil spillage.
19Examine the condition of the sealing ring,
and renew if necessary.
Refitting
20Refitting is a reversal of removal. On
completion, check, and if necessary top-up,
the engine oil level.
Bulb failure sensor
Removal
21The bulb failure sensor is mounted behind
the fuse/relay panel in the facia.
22Release the retaining clips from the lower
end of the fuse/relay panel, and tilt it forwards.23Reach up behind the fuse/relay panel, and
pull the sensor from its socket.
Refitting
24Refitting is a reversal of removal.
22Horn(s) - removal and refitting
2
1On models with a single horn, the horn is
located in front of the radiator. On models
with twin horns, the horns are located beneath
the washer fluid reservoir, at the left-hand end
of the front bumper.
Single horn
Removal
2Disconnect the battery negative lead.
3Remove the radiator grille panel, with
reference to Chapter 11.
4Disconnect the wiring from the rear of the
horn.
5Reach up behind the mounting bracket, and
unscrew the single nut securing the horn to the
bracket (see illustration). Withdraw the horn.
Refitting
6Refitting is a reversal of removal.
Twin horns
Removal
7Disconnect the battery negative lead.
8Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands (see “Jacking and Vehicle Support”)
positioned under the body side members.
9Remove the securing screws, and withdraw
the plastic cover (where fitted) from the
bumper/front wing to expose the horns.
10Remove the bolt securing the horn
mounting bracket to the bracket below the
washer fluid reservoir (see illustration).
11Withdraw the horns and disconnect the
wiring.
12If desired, the horns can be unbolted from
the bracket.
Refitting
13Refitting is a reversal of removal.
23Interior lamps - removal and
refitting
2
Removal
1Disconnect the battery negative lead.
2Using a thin-bladed screwdriver, prise the
lamp from its location and disconnect the
wiring (see illustration).
Refitting
3Refitting is a reversal of removal.
24Interior lamp bulbs - renewal
1
1Disconnect the battery negative lead.
Courtesy lamp
Note: Some later models are fitted with
courtesy lamps for the rear seat passengers,
as well as front.
Removal
2Using a thin-bladed screwdriver, prise the
lamp from its location and disconnect the
wiring.
3On models fitted with a courtesy lamp with
integral map reading lamps, the lens must be
levered from the housing for access to the
bulbs.
12•8Body electrical systems
21.18 Engine oil level sensor - DOHC model
22.10 Horn mounting bracket securing
bolt (arrowed) - twin horned model23.2 Withdrawing the courtesy lamp
22.5 Horn viewed from behind with radiator removed - single
horned model

16If adjustment is necessary, slacken the
locknut, turn the fork to give the specified
dimension, then tighten the locknut.
17Where applicable, coat the contact faces
of the servo and the mounting bracket with
sealing compound, then refit the bracket to
the servo, and tighten the securing nuts to the
specified torque.
18Coat the threads of the servo securing
bolts with locking fluid, then fit the servo to
the bulkhead and tighten the securing bolts.
19Refit the securing bolt cover plugs to the
cowl panel.
20Refit the master cylinder to the servo, and
tighten the securing nuts to the specified
torque.
21Reconnect the vacuum pipe to the servo.
22Refit the coolant expansion tank, as
described in Chapter 3.
23Refit the windscreen wiper motor and
linkage as described in Chapter 12, then refit
the windscreen cowl panel.
24Further refitting is a reversal of removal.
On completion, test the operation of the
servo, as described in Section 18.
20ABS hydraulic modulator -
removal and refitting
4
Note: Refer to Section 2, and the note at the
beginning of Section 3, before proceeding
Removal
1Disconnect the battery negative lead.
2Remove the brake fluid reservoir cap, and
secure a piece of polythene over the filler
neck with a rubber band, or by refitting the
cap. This will reduce the loss of fluid during
the following procedure.
3Remove the securing screw, and withdraw
the plastic cover from the hydraulic
modulator.
4Remove the two clamp screws, and lift off
the modulator wiring harness clamp (see
illustration).
5Disconnect the modulator wiring plug,
levering it from the socket with a screwdriver if
necessary.6Unscrew the brake fluid pipe union nuts,
and disconnect the pipes from the modulator.
Be prepared for fluid spillage, and plug the
open ends to prevent dirt ingress and further
fluid loss. Move the pipes just clear of the
modulator, taking care not to strain them.
7Unscrew the three modulator securing nuts
(see illustration), then tilt the modulator
slightly, and withdraw it upwards from its
bracket, sufficiently to gain access to the
earth lead securing nut at the front lower edge
of the modulator.
8Unscrew the securing nut and disconnect
the earth lead, then withdraw the modulator
from the vehicle, taking care not to spill brake
fluid on the vehicle paintwork.
9If a new modulator is to be fitted, pull the
two relays from the top of the old modulator,
and transfer them to the new unit. No attempt
must be made to dismantle the modulator.
Refitting
10Before refitting the modulator, check that
the bolts securing the mounting bracket to the
body panel are tight, and that the modulator
rubber mountings are in good condition.
Renew the rubber mountings if necessary.
11Refitting is a reversal of removal,
remembering the following points.
12Make sure that the earth lead is
reconnected before fitting the modulator to its
mounting bracket.13On completion, remove the polythene
sheet from the brake fluid reservoir filler neck,
and bleed the complete brake hydraulic
system, as described in Section 3.
14Check that the ABS warning lamp
extinguishes when first starting the engine
after the modulator has been removed. At the
earliest opportunity, take the vehicle to a
Vauxhall dealer, and have the complete
system tested, using the dedicated ABS test
equipment.
21ABS wheel sensors - removal
and refitting
3
Note: Refer to Section 2 before proceeding
Front wheel sensor
Removal
1Disconnect the battery negative lead.
2Where applicable, remove the wheel trim,
then loosen the relevant front roadwheel bolts
and apply the handbrake. Jack up the front of
the vehicle, and support on axle stands (see
“Jacking and Vehicle Support”) positioned
under the body side members. Remove the
roadwheel.
3Unclip the sensor wiring connector from the
retaining clip under the wheel arch, then
separate the two halves of the wiring
connector, prising them apart with a
screwdriver if necessary (see illustration).
4Using a Allen key or hexagon bit, unscrew
the bolt securing the wheel sensor to its
mounting bracket, then carefully lever the
sensor from the bracket using a screwdriver
(see illustration). Recover the seal ring.
Refitting
5Examine the condition of the seal ring, and
renew if necessary.
6Refitting is a reversal of removal,
remembering the following points.
7Smear a little grease on the sensor casing
before fitting it to the bracket.
8Do not fully tighten the roadwheel bolts until
the vehicle is resting on its wheels.
9Check that the ABS warning lamp
extinguishes when first starting the engine
after a wheel sensor has been removed. At
9•16Braking system
20.4 ABS hydraulic modulator (cover
removed)
1 Wiring harness
clamp screws2 Earth lead
3 Relays
21.3 Front wheel sensor wiring under
wheelarch - DOHC model
1 ABS sensor connector
2 Disc pad wear sensor wiring connector
21.4 ABS front wheel sensor securing bolt
(arrowed) - DOHC model20.7 ABS hydraulic modulator securing
screws (arrowed)

4B
cruising and accelerating. The injector earth is
also switched off on the overrun to improve
fuel economy and reduce exhaust emissions.
Additionally, on the X16 SZ engine, the ECU
also controls the operation of the charcoal
canister purge valve in the evaporative
emission control system.
10The oxygen sensor screwed into the
exhaust manifold provides the ECU with a
constant feedback signal. This enables it to
adjust the mixture (closed-loop control) to
provide the best possible conditions for the
catalytic converter to operate effectively.
11Until the oxygen sensor is fully warmed up
it gives no feedback so the ECU uses
pre-programmed values (open-loop control) to
determine the correct injector pulse width.
When the sensor reaches its normal operating
temperature, its tip (which is sensitive to
oxygen) sends the ECU a varying voltage
depending on the amount of oxygen in the
exhaust gases. If the inlet air/fuel mixture is too
rich, the exhaust gases are low in oxygen so the
sensor sends a low-voltage signal. The voltage
rises as the mixture weakens and the amount of
oxygen rises in the exhaust gases. Peak
conversion efficiency of all major pollutants
occurs if the inlet air/fuel mixture is maintained
at the chemically correct ratio for the complete
combustion of petrol of 14.7 parts (by weight) of
air to 1 part of fuel (the “stoichiometric” ratio).
The sensor output voltage alters in a large step
at this point, the ECU using the signal change
as a reference point and correcting the inlet
air/fuel mixture accordingly by altering the fuel
injector pulse width.
12In addition, the ECU senses battery
voltage, incorporates diagnostic capabilities,
and can both receive and transmit information
by way of the diagnostic connector, thus
permitting engine diagnosis and tuning by
Vauxhall’s TECH1, test equipment.
Motronic system
13The Motronic type is available in several
different versions, depending on model. The
system is under the overall control of the
Motronic engine management system (Chapter
5), which also controls the ignition timing.
14Fuel is supplied from the rear-mounted
fuel tank by an electric fuel pump mounted
under the rear of the vehicle, through a
pressure regulator, to the fuel rail. The fuel rail
acts as a reservoir for the four fuel injectors,
which inject fuel into the cylinder inlet tracts,
upstream of the inlet valves. On SOHC
engines, the fuel injectors receive an electrical
pulse once per crankshaft revolution, which
operates all four injectors simultaneously. On
DOHC engines, sequential fuel injection is
used, whereby each injector receives an
individual electrical pulse allowing the four
injectors to operate independently, which
enables finer control of the fuel supply to each
cylinder. The duration of the electrical pulse
determines the quantity of fuel-injected, and
pulse duration is computed by the Motronic
module, based on the information received
from the various sensors.15On SOHC engines, inlet air passes from
the air cleaner through a vane type airflow
meter, before passing to the cylinder inlet
tracts through the throttle valve. A flap in the
vane airflow meter is deflected in proportion
to the airflow; this deflection is converted into
an electrical signal, and passed to the
Motronic module. A potentiometer screw
located on the airflow meter provides the
means of idle mixture adjustment, by altering
the reference voltage supplied to the Motronic
module.
16On DOHC engines, inlet air passes from
the air cleaner through a hot wire type air
mass meter, before passing to the cylinder
inlet tracts through a two-stage throttle body
assembly. The electrical current required to
maintain the temperature of the hot wire in the
air mass meter is directly proportional to the
mass flow rate of the air trying to cool it. The
current is converted into a signal, which is
passed to the Motronic module. The throttle
body contains two throttle valves that open
progressively, allowing high torque at part
throttle, and full-throttle, high-speed
“breathing” capacity. A potentiometer screw
located on the air mass meter provides the
means of idle mixture adjustment, by altering
the reference voltage supplied to the Motronic
module.
17A throttle position sensor enables the
Motronic module to compute the throttle
position, and on certain models, its rate of
change. Extra fuel can thus be provided for
acceleration when the throttle is opened
suddenly. Information from the throttle
position sensor is also used to cut off the fuel
supply on the overrun, thus improving fuel
economy and reducing exhaust gas
emissions.
18Idle speed is controlled by a variable-
orifice solenoid valve, which regulates the
amount of air bypassing the throttle valve. The
valve is controlled by the Motronic module;
there is no provision for direct adjustment of
the idle speed.
19Additional sensors inform the Motronic
module of engine coolant temperature, air
temperature, and on models fitted with a
catalytic converter, exhaust gas oxygen
content.
20A fuel filter is incorporated in the fuel
supply line, to ensure that the fuel supplied to
the injectors is clean.
21A fuel pump cut-off relay is controlled by
the Motronic module, which cuts the power to
the fuel pump should the engine stop with the
ignition switched on, if there is an accident. All
1993-onwards models equipped with
Motronic systems, have their fuel pump
located inside the fuel tank.
22The later M2.8 system is basically the
same as the earlier M2.5 system apart from
the following:
a)Hot Film Mass Airflow Meter - The hot
wire type unit used previously is replaced
on the M2.8 system by a hot film mass
airflow meter. The operation is the sameexcept that a thin, electrically heated plate
rather than a wire is used. The plate is
maintained at a constant temperature by
electric current as the inlet air mass
passing over the plate tries to cool it. The
current required to maintain the
temperature of the plate is directly
proportional to the mass flow rate of the
inlet air. The current is converted to a
signal that is passed to the Motronic
module.
b)Inlet Air Temperature Sensor -The sensor
is located in the hose between the hot
film mass airflow meter and the air cleaner
for precise monitoring of inlet air
temperature. Signals from the sensor are
used in conjunction with other sensors to
indicate the occurrence of a hot start
condition. The Motronic module then
interprets these signals to alter injector
duration accordingly.
c)Throttle Valve Potentiometer -On the
M2.8 system a throttle valve
potentiometer replaces the throttle valve
switch used previously.
Simtec system
23An increased amount of electronic
components are used 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.
24The 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).
25The ignition coil is replaced by a dual
spark ignition coil, which is switched directly
by the output stages in the control unit.
26A 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.
27The ‘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.
28The air inlet temperature sensor (NTC), is
fitted in the air inlet duct between the air
cleaner and the hot mass air flow meter.
29A 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.
30A knock control system is also fitted. This
eliminates the need for octane number
adjustment, as it is performed automatically
through the control unit.
Fuel and exhaust systems - fuel injection models 4B•3

Maintenance - component location 1•5
1
Underbonnet view of a 1989 1.6 L model (16 SV engine)
1 VIN plate
2 Air cleaner casing *
3 Suspension strut top
4 Coolant expansion tank
5 Brake fluid reservoir
6 Fuel pump
7 Steering rack
8 Octane rating plug
9 Washer fluid reservoir
10 Battery
11 Ignition coil
12 Distributor (Bosch type)
13 Cooling fan motor
14 Engine oil level dipstick
15 Oil filter
16 Oil filler cap
* Refer to Chapter 4A for
alternative type
Underbonnet view of a 1991 model Cavalier 1.6 L (C16 NZ engine)
1 Air cleaner casing
2 Suspension strut top
3 Coolant expansion tank
4 Brake fluid reservoir
5 Air box
6 Exhaust gas recirculation valve
7 Steering gear
8 Octane coding plug
9 Washer fluid reservoir
10 Battery
11 Ignition coil
12 Distributor
13 Cooling fan motor
14 Engine oil level dipstick
15 Engine oil filter
16 Oxygen sensor
17 Engine oil filler cap

1•6Maintenance - component location
Underbonnet view of a 1989 2.0 SRi model (20 SEH engine)
1 VIN plate
2 Air cleaner casing
3 Airflow meter
4 Suspension strut top
5 Coolant expansion tank
6 Brake fluid reservoir
7 Throttle body
8 Relay box
9 Octane rating plug
10 Washer fluid reservoir
11 Battery
12 Power steering fluid reservoir
13 Power steering fluid hoses
14 Distributor cap
15 Engine oil level dipstick
16 Idle speed adjuster
17 Fuel pressure regulator
18 Oil filler cap
19 Thermostat housing
Underbonnet view of a 1990 GSi 2000 model (20 XEJ engine)
1 VIN plate
2 Air cleaner casing
3 Suspension strut top
4 Coolant expansion tank
5 Brake fluid reservoir
6 Air mass meter
7 Fuel pressure regulator
8 Relay box
9 Anti-theft alarm horn
10 ABS hydraulic modulator
11 Washer fluid reservoir
12 Power steering fluid reservoir
13 Battery
14 Distributor
15 Engine oil level dipstick
16 Oil filler cap