1988 OPEL CALIBRA engine oil

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

2When the starter switch is operated, current
flows from the battery to the solenoid that is
mounted on the starter body. The plunger in
the solenoid moves inwards, so causing a
centrally pivoted lever to push the drive pinion
into mesh with the starter ring gear. When the
solenoid plunger reaches the end of its travel,
it closes an internal contact and full starting
current flows to the starter field coils. The
armature is then able to rotate the crankshaft,
so starting the engine.
3A special freewheel clutch is fitted to the
starter driven pinion, so that when the engine
fires and starts to operate on its own it does
not drive the starter motor.
4When the starter switch is released, the
solenoid is de-energised, and a spring moves
the plunger back to its rest position. This
operates the pivoted lever to the withdraw the
drive pinion from engagement with the starter
ring.
13Starter motor - testing
3
Note: Refer to Section 3 before proceeding
Testing
1If the starter motor fails to turn the engine
when the switch is operated, and engine
seizure is not the problem, there are several
other possible reasons:
a)The battery is faulty
b)The electrical connections between the
switch, solenoid battery and starter motor
are somewhere failing to pass the
necessary current from the battery
through the starter to earth
c)The solenoid switch is faulty
d)The starter motor is mechanically or
electrically defective
e)The starter motor pinion and/or flywheel
ring gear is badly worn, and in need of
replacement
2To check the battery, switch on the
headlamps. If they dim after a few seconds,
then the battery is in a discharged state. If the
lamps glow brightly, operate the starter switch
and see what happens to the lamps. If theydim, then power is reaching the motor, but
failing to turn it. If the starter turns slowly, go
on to the next check.
3If, when the starter switch is operated, the
lamps stay bright, then insufficient power is
reaching the motor. Disconnect the battery
and the starter/solenoid power connections,
and the engine earth strap, then thoroughly
clean them and refit them. Smear petroleum
jelly around the battery connections to
prevent corrosion. Corroded connections are
the most frequent cause of electrical system
malfunctions.
4If the preceding checks and cleaning tasks
have been carried out without success, a
clicking noise will probably have been heard
each time the starter switch was operated.
This indicates that the solenoid switch was
operating, but it does not necessarily follow
that the main contacts were closing properly
(if no clicking has been heard from the
solenoid, it is certainly defective). The
solenoid can be checked by connecting a
voltmeter across the main cable connection
on the solenoid and earth. When the switch is
operated, these should be a reading on the
voltmeter. If there is no reading, the solenoid
unit is faulty, and should be renewed.
5If the starter motor operates, but does not
turn the engine, then it is likely that the starter
pinion and/or flywheel ring gear are badly
worn. If this is the case, the starter motor will
normally be noisy in operation.
6Finally, if it is established that the solenoid
is not faulty, and 12 volts are reaching the
starter, then the motor itself is faulty, and
should be removed for inspection.
14Starter motor - removal and
refitting
3
Note: Refer to Section 3 before proceeding
Removal
1Disconnect the battery negative lead.
2Apply 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.3On DOHC models, remove the engine
undershield, as described in Chapter 11.
4Note the wiring connections on the
solenoid, then disconnect them (see
illustration).
5Where applicable, unscrew the bolt
securing the exhaust bracket and the starter
motor mounting bracket to the cylinder block
(see illustration).
6Unscrew the two starter motor mounting
bolts. Note that the top bolt on some models
are fitted from the transmission side, and
secures a wiring harness bracket (see
illustration).
7Withdraw the starter motor.
Refitting
8Refitting is a reversal of removal, but where
applicable, ensure that the wiring harness
bracket is in place on the top mounting bolt,
and tighten all bolts to the specified torque.
15Starter motor - overhaul
5
If the starter motor is thought to be suspect,
it should be removed from the vehicle and
taken to an auto-electrician for testing. Most
auto-electricians will be able to supply and fit
brushes at a reasonable cost. However, check
on the cost of repairs before continuing as it
may prove more economical to obtain a new
or exchange motor.
16Ignition coil - removal, testing
and refitting
3
Note: Refer to Section 3 before proceeding.
An ohmmeter will be required to test the coil
Removal
1The ignition coil is either a cylindrical metal
canister or a moulded plastic unit. It is
clamped or bolted to the left-hand inner wing
panel, near the suspension strut top mounting
(under the power steering fluid reservoir, on
Engine electrical systems 5•9
14.6 Starter motor securing bolts
(arrowed) - 1.6 litre model
(engine removed)14.5 Starter motor mounting
bracket/exhaust bracket securing bolt
(arrowed) - 1.6 litre model14.4 Starter motor and solenoid viewed
from underneath the vehicle. Solenoid
wiring connections arrowed
5

models so equipped). On 14 NV, 16 SV and
18 SV models, the ignition amplifier module is
mounted on the coil’s bracket or baseplate
(see illustration).
2Disconnect the battery negative lead.
3Carefully note the LT wiring connections
before disconnecting them (see illustration).
4Note that on models with power steering,
one of the coil securing bolts also secures the
power steering fluid reservoir bracket.
5Remove the coil.
6On models with a cylindrical type coil, the
mounting clamp can be removed from the coil
by loosening the clamp nut.
Testing
7To test the coil, first disconnect the LT
wiring and the HT lead. Test the coil’s primary
windings by connecting a multi-meter across
the LT terminals (“+” or “15” and “-” or “1”).Then the secondary windings by testing
across the HT terminal (“4”) and one of the LT
terminals (usually the “-/1” terminal, although
in some cases, either terminal may serve). On
20 XEJ models, results should closely
approximate the specified values. On all other
models, typical primary resistances are less
than 1 ohm, while secondary resistances can
be expected to be in the 4000 to 12 000 ohms
range.
8If the results obtained differ significantly
from those given, showing windings that are
shorted or open circuit, the coil must be
renewed.
Refitting
9Refitting is a reversal of removal, however
ensure correct connections. Usually they are
physically different to prevent incorrect
refitting. If not, use the terminal marks ornumbers in conjunction with the relevant
wiring diagram at the back of this manual to
ensure that the connections are correctly
remade. If the connections are reversed, so
will the coil’s polarity be. While the engine
may still run, spark plug life will be reduced
and poor starting and/or misfiring may follow.
10Where applicable, ensure that the coil
suppresser is in position before refitting the
coil securing bolts.
17Distributor cap and rotor
arm -removal and refitting
3
Note: Refer to Section 3 before proceeding
Removal
14 NV and 16 SV models
1Disconnect the battery negative lead.
2Identify each HT lead for position, so that
the leads can be refitted to their correct
cylinders, then disconnect the leads from the
spark plugs by pulling on the connectors, not
the leads. Similarly, disconnect the HT lead
from the coil. Pull the leads from the clips on
the camshaft cover.
3On the Bosch distributor, prise away the
two spring clips with a screwdriver, and lift off
the distributor cap. On the Lucas distributor,
unscrew the two small bolts and lift off the
cap (see illustrations).
4The rotor arm is a push fit on the end of the
distributor shaft.
5If needed, on the Bosch distributor, the
plastic shield can be pulled from the end of
the distributor, to allow examination of the
distributor components (see illustration).
Other models, where applicable
6Proceed as described in paragraphs 1 and 2.
7On DOHC models (except X20 XEV),
unscrew the two securing bolts and withdraw
the spark plug cover from the camshaft cover.
8Using a Torx socket, unscrew the three
captive securing screws and withdraw the
distributor cap (see illustration).
9Withdraw the plastic shield from the rotor
arm housing. The shield is fitted in the
housing, with an O-ring seal located in a
groove in its periphery. Ease out the shield,
taking care not to damage the rotor arm (see
illustration).
5•10Engine electrical systems
16.1 Ignition coil - 1.6 litre models - note
ignition timing basic adjustment coding
plug (arrowed)
17.3A Removing the distributor cap -
1.6 litre model (Bosch distributor) . . .
17.9 Removing the plastic shield from the
rotor arm housing - 2.0 litre model17.8 Unscrewing a distributor cap
securing screw - 2.0 litre model17.5 Removing the rotor arm and plastic
shield - 1.6 litre model (Bosch distributor)
17.3B . . .and 1.6 litre models (Lucas
distributor)
16.3 Disconnecting the coil LT wiring plug
- 2.0 litre model

Inspection
17Examine the distributor cap and rotor arm,
as described in paragraphs 6 and 7. Examine
the O-rings at the rear of the distributor body,
and on the rear of the shaft, and renew if
necessary.
Reassembly
18Reassembly is a reversal of dismantling,
ensuring that the thrustwashers are correctly
located. Note that the drive collar should be
refitted so that the drive peg on the collar is
aligned with the groove in the top of the
distributor shaft (it is possible to fit the drive
collar 180°out of position).
19Refit the distributor as described in
Section 18, and then check and if necessary
adjust the ignition timing, as described in
Section 21.
DOHC models (where
applicable)
20The distributor cap and rotor arm can be
examined as described in paragraphs 6 and 7.
21Ignition timing -checking and
adjustment
4
Note: Refer to Section 3 before proceeding. A
tachometer and a timing light will be required
during this procedure. For details of ignition
timing adjustment required to operate vehicles
on unleaded petrol, refer to Section 22.
14 NV and 16 SV models
Checking
1Start the engine and run it until it reaches
normal operating temperature, then switch
off.
2On 14 NV models, disconnect the vacuum
pipe from the distributor vacuum diaphragm
unit.
3On all models use a spanner applied to the
crankshaft pulley bolt to rotate the crankshaft
clockwise until the notch in the pulley’s
inboard rim aligns with the pointer protruding
from the oil pump housing. On 14 NV models,
where two notches (indicating 10°and 5°
BTDC respectively) are found, rotate the
crankshaft until the second notch (in thedirection of rotation -i.e. 5°BTDC) aligns. Use
white paint or similar to emphasise the pointer
and notch, to make them easier to see.
4Connect a timing light to No 1 cylinder
(nearest the timing belt end of the engine) HT
lead, also a tachometer; follow the equipment
manufacturer’s instructions for connection.
5Start the engine and allow it to idle -the
speed should be between 700 and 1000 rpm.
6On 14 NV models, aim the timing light at the
pointer and check that it is aligned with the
crankshaft pulley notch.
7On early 16 SV models, disconnect the
ignition timing basic adjustment coding plug.
This can be identified by a length of Black
wire joining Brown/Red and Brown/Yellow
wires in a connector plug clipped to the wiring
or heater/cooling system hoses beneath the
battery/ignition coil (see illustration, 16.1). This
causes the MSTS-i module to adopt its basic
adjustment mode, sending a constant firing
signal corresponding to 10°BTDC and
eliminating any advance below 2000 rpm. Aim
the timing light at the pointer and check that it
is aligned with the crankshaft pulley notch.
8On later 16 SV, C 16 NZ and C 16 NZ2
models, the coding plugs are no longer fitted.
For accurate checking, special Vauxhall test
equipment must be used which causes the
MSTS module to adopt its basic adjustment
mode.
9Without access to such equipment, it is
possible to check and adjust the ignition
timing, accurate results cannot be
guaranteed. Owners are therefore advised to
have this work carried out by a suitably
equipped Vauxhall dealer; at the very least,
make the initial setting yourself and then have
it checked as soon as possible.
10If you do attempt to check the ignition
timing yourself, note that the fixed reference
mark is now an extended line embossed on
the timing belt lower outer cover.
Adjustment
11If the notch and pointer are not aligned,
loosen the distributor clamp nut and turn the
distributor body slightly in the required
direction to align.
12Tighten the distributor clamp nut, and
check that the notch and pointer are still
aligned. 13Stop the engine, and disconnect the
timing light and tachometer.
14On 16 SV models, reconnect the basic
adjustment coding plug. On 14 NV models,
reconnect the vacuum pipe to the distributor
vacuum diaphragm unit.
Other models
15No adjustment of the ignition timing is
possible on 1.8 and 2.0 litre models, as the
adjustment is carried out automatically by the
electronic control module.
16The ignition timing can be checked by a
Vauxhall dealer using specialist dedicated test
equipment, if a fault is suspected.
22Ignition timing -adjustment
for use with unleaded petrol
3
14 NV models
1All models with the 14 NV engine have the
ignition timing adjusted for use with 95 RON
unleaded petrol before they leave the factory,
and no further adjustment is required.
2Leaded petrol (98 RON) can be used if
desired, with no adverse effects.
1.6, 1.8 and 2.0 SOHC models
Note: Models equipped with a catalytic
converter must be operated on 95 R0N
unleaded petrol at all times, and although an
octane coding plug may be fitted, it should
not be tampered with
3Models, other than 14 NV, are equipped
with an octane coding plug, which is located
Engine electrical systems 5•13
20.16B . . .and withdraw the sensor plate -
1.6 litre (Bosch distributor)
20.16C Sensor plate screw (arrowed) -
1.6 litre (Lucas distributor)
20.16A Remove the securing screws . . .20.15B . . .and disconnecting the small
wiring plug - 1.6 litre (Lucas distributor)
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

3Lift up the edge of the windscreen cowl
panel for access to the sensor.
4Disconnect the sensor wiring plug, and the
vacuum pipe.
5Pull the pressure sensor upwards to release
it from its bracket, and withdraw it from the
vehicle.
Refitting
6Refitting is a reversal of removal. However,
on Multec models no fuel vapour trap is fitted.
It is therefore essential that the sensor
vacuum hose is routed so that it falls steadily
from the sensor to the throttle body. This
precaution prevents any fuel droplets being
trapped in the sensor or hose, and allows
them to drain into the inlet port.
Oil temperature sensor
Removal
7The sensor is screwed into the inlet
manifold side of the cylinder block, next to the
starter motor’s right-hand end.
8The sensor can be reached quite easily
from above, but if it is to be removed from
beneath, ensure that the handbrake is
applied, and that the vehicle is securely
supported on axle stands (see “Jacking and
Vehicle Support”).
9Disconnect the battery negative lead.
10Disconnect the sensor wiring plug.
11Using a spanner, unscrew the sensor and
remove it (see illustration). Be prepared for
oil spillage, and plug the hole in the cylinder
block to prevent dirt ingress and further oil
loss.
Refitting
12Refitting is a reversal of removal.
Crankshaft speed/position
sensor (1.8 litre models)
Removal
13The sensor is located on the exhaust
manifold side of the engine, in the lower
cylinder block behind the oil pump.
14Disconnect the battery negative lead.
15Release the relevant outer timing belt
cover securing clips, and unclip the sensor
wiring from the timing belt cover.
16Disconnect the sensor wiring connector,
noting its location.
17Unscrew the securing bolt, and withdraw
the sensor from the cylinder block (see
illustration).
18Examine the sensor sealing ring, and
renew if necessary (see illustration).
Refitting
19Refitting is a reversal of removal, ensuring
that the sensor wiring is correctly located on
the timing belt cover, and that the wiring
connector is correctly located.
25Motronic system
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. Removal and
refitting procedures for all fuel injection
system components are given in Chapter 4B
Coolant temperature sensor
Removal
1On all except 20 XEJ models, the sensor is
located in the end of the thermostat housing,
on the inlet manifold side of the engine.
2On 20 XEJ models, the sensor is located in
the thermostat housing, on the exhaust
manifold side of the engine.
3Disconnect the battery negative lead.
4Partially drain the cooling system, as
described in Chapter 3. 5Disconnect the sensor wiring plug (see
illustration).
6Using a spanner, unscrew the sensor and
withdraw it from the thermostat housing.
Refitting
7Refitting is a reversal of removal.
8On completion, top-up the cooling system,
as described in Chapter 3.
Knock sensor (DOHC models)
Removal
9The sensor is located at the lower inlet
manifold side of the cylinder block, below the
idle speed adjuster, and is only accessible
from below the vehicle.
10Disconnect the battery negative lead.
11Apply the handbrake, then jack up the
front of the vehicle, and support securely on
axle stands (see “Jacking and Vehicle
Support”) placed under the body side
members.
12Remove the engine undershield, as
described in Chapter 11.
13Disconnect the sensor wiring plug.
14Unscrew the securing bolt, and withdraw
the sensor from the cylinder block.
Refitting
15Refitting is a reversal of removal, but note
that the mating faces of the sensor and
cylinder block must be cleaned thoroughly
before fitting the sensor.
Engine electrical systems 5•15
24.17 Unscrewing the crankshaft
speed/position sensor securing bolt -
1.8 litre model
25.5 Disconnecting the coolant
temperature sensor wiring plug - 2.0 litre
model (alternator removed)24.18 Examine the crankshaft
speed/position sensor sealing ring -
1.8 litre model
24.11 Unscrewing the MSTS-i oil
temperature sensor - 1.6 litre model
(engine removed)24.1 MSTS-i manifold pressure sensor -
1.6 litre model
5

wax-based underbody protective coating, it is
a good idea to have the whole of the
underframe of the vehicle steam cleaned,
engine compartment included, so that a
thorough inspection can be carried out to see
what minor repairs and renovations are
necessary. Steam cleaning is available at
many garages and is necessary for removal of
the accumulation of oily grime that sometimes
is allowed to become thick in certain areas.
The dirt can then be simply hosed off. Note
that these methods should not be used on
vehicles with wax-based underbody
protective coating or the coating will be
removed. Such vehicles should be inspected
annually, preferably just before winter, when
the underbody should be washed down and
any damage to the wax coating repaired.
Ideally, a completely fresh coat should be
applied. It would also be worth considering
the use of such wax-based protection for
injection into door panels, sills, box sections,
etc., as an additional safeguard against rust
damage where such protection is not
provided by the vehicle manufacturer.
After washing paintwork, wipe off with a
chamois leather to give an unspotted clear
finish. A coat of clear protective wax polish,
will give added protection against chemical
pollutants in the air. If the paintwork sheen
has dulled or oxidised, use a cleaner/polisher
combination to restore the brilliance of the
shine. This requires a little effort, but such
dulling is usually caused because regular
washing has been neglected. Care needs to
be taken with metallic paintwork, as special
non-abrasive cleaner/polisher is required to
avoid damage to the finish.
Always check that the door and ventilator
opening drain holes and pipes are completely
clear so that water can be drained out. Bright
work should be treated in the same way as
paint work. Windscreens and windows can be
kept clear of the smeary film that often
appears, by using a glass cleaner. Never use
any form of wax or other body or chromium
polish on glass.
3Upholstery and carpets -
maintenance
1
Mats and carpets should be brushed or
vacuum cleaned regularly to keep them free of
grit. If they are badly stained remove them
from the vehicle for scrubbing or sponging
and make quite sure they are dry before
refitting. Seats and interior trim panels can be
kept clean by wiping with a damp cloth. If they
do become stained (which can be more
apparent on light coloured upholstery) use a
little liquid detergent and a soft nail brush to
scour the grime out of the grain of the
material. Do not forget to keep the headlining
clean in the same way as the upholstery.
When using liquid cleaners inside the vehicle
do not over-wet the surfaces being cleaned.Excessive damp could get into the seams and
padded interior causing stains, offensive
odours or even rot. If the inside of the vehicle
gets wet accidentally it is worthwhile taking
some trouble to dry it out properly, particularly
where carpets are involved. Do not leave oil or
electric heaters inside the vehicle for this
purpose.
4Minor body damage - repair
3
Repairs of minor scratches in
bodywork
If the scratch is very superficial, and does
not penetrate to the metal of the bodywork,
repair is very simple. Lightly rub the area of
the scratch with a paintwork renovator, to
remove loose paint from the scratch and to
clear the surrounding bodywork of wax polish.
Rinse the area with clean water.
Apply touch-up paint to the scratch using a
fine paint brush; continue to apply fine layers
of paint until the surface of the paint in the
scratch is level with the surrounding
paintwork. Allow the new paint at least two
weeks to harden: then blend it into the
surrounding paintwork by rubbing the scratch
area with a paintwork renovator or a very fine
cutting paste and apply wax polish.
Where the scratch has penetrated right
through to the metal of the bodywork, causing
the metal to rust, a different repair technique
is required. Remove any loose rust from the
bottom of the scratch with a penknife, then
apply rust inhibiting paint, to prevent the
formation of rust in the future. Using a rubber
or nylon applicator fill the scratch with
bodystopper paste. If required, this paste can
be mixed with cellulose thinners to provide a
very thin paste that is ideal for filling narrow
scratches. Before the stopper-paste in the
scratch hardens, wrap a piece of smooth
cotton rag around the top of a finger. Dip the
finger in cellulose thinners and then quickly
sweep it across the surface of the
stopper-paste in the scratch; this will ensure
that the surface of the stopper-paste is
slightly hollowed. The scratch can now be
painted over as described earlier in this
Section.
Repair of dents in bodywork
When deep denting of the vehicle’s
bodywork has taken place, the first task is to
pull the dent out, until the affected bodywork
almost attains its original shape. There is little
point in trying to restore the original shape
completely, as the metal in the damaged area
will have stretched on impact and cannot be
reshaped fully to its original contour. It is
better to bring the level of the dent up to a
point that is about 8 in (3 mm) below the level
of the surrounding bodywork. In cases where
the dent is very shallow anyway, it is not worthtrying to pull it out at all. If the underside of the
dent is accessible, it can be hammered out
gently from behind, using a mallet with a
wooden or plastic head. Whilst doing this,
hold a block of wood firmly against the
outside of the panel to absorb the impact
from the hammer blows and thus prevent a
large area of the bodywork from being
“belled-out”.
Should the dent be in a section of the
bodywork that has a double skin or some
other factor making it inaccessible from
behind, a different technique is called for. Drill
several small holes through the metal inside
the area particularly in the deeper section.
Then screw long self-tapping screws into the
holes just sufficiently for them to gain a good
purchase in the metal. Now the dent can be
pulled out by pulling on the protruding heads
of the screws with a pair of pliers.
The next stage of the repair is the removal
of the paint from the damaged area, and from
an inch or so of the surrounding “sound”
bodywork. This is accomplished most easily
by using a wire brush or abrasive pad on a
power drill, although it can be done just as
effectively by hand using sheets of abrasive
paper. To complete the preparation for filling,
score the surface of the bare metal with a
screwdriver or the tang of a file, or
alternatively, drill small holes in the affected
area. This will provide a good “key” for the
filler paste.
To complete the repair see the Section on
filling and re-spraying.
Repair of rust holes or gashes in
bodywork
Remove all paint from the affected area and
from an inch or so of the surrounding “sound”
bodywork, using an abrasive pad or a wire
brush on a power drill. If these are not
available a few sheets of abrasive paper will
do the job just as effectively. With the paint
removed you will be able to gauge the severity
of the corrosion and therefore decide whether
to renew the whole panel (if this is possible) or
to repair the affected area. New body panels
are not as expensive as most people think
and it is often quicker and more satisfactory
to fit a new panel than to attempt to repair
large areas of corrosion.
Remove all fittings from the affected area
except those which will act as a guide to the
original shape of the damaged bodywork (e.g.
headlamp shells, etc.). Then, using tin snips or
a hacksaw blade, remove all loose metal and
any other metal badly affected by corrosion.
Hammer the edges of the hole inwards to
create a slight depression for the filler paste.
Wire brush the affected area to remove the
powdery rust from the surface of the
remaining metal. Paint the affected area with
rust inhibiting paint. If the back of the rusted
area is accessible treat this also.
Before filling can take place it will be
necessary to block the hole in some way. This
can be achieved by using aluminium or plastic
mesh, or aluminium tape.
11•2Bodywork and fittings