1988 OPEL CALIBRA coolant

2A separate idle system operates
independently from the main jet system,
supplying fuel by way of the mixture control
screw.
3The main jets are calibrated to suit engine
requirements at mid-range throttle openings.
To provide the necessary fuel enrichment at
full throttle, a vacuum-operated power valve is
used. The valve provides extra fuel under the
low vacuum conditions associated with wide
throttle openings.
4To provide an enriched mixture during
acceleration, an accelerator pump delivers
extra fuel to the primary main venturi. The
accelerator pump is operated mechanically by
a cam on the throttle linkage.
5A fully automatic choke is fitted, operated
by a coolant and electrically heated bi-metal
coil. When the engine is cold, the bi-metal coil
is fully wound up, holding the choke plate
(fitted to the primary barrel) closed. As the
engine warms up, the bi-metal coil is heated
and therefore unwinds, progressively opening
the choke plate. A vacuum operated pull-
down system is employed, whereby, if the
engine is under choke but is only cruising (i.e.
not under heavy load) the choke plate is
opened against the action of the bi-metal coil.
The pull-down system prevents an over-rich
mixture, which reduces fuel economy and
may cause unnecessary engine wear when
the engine is cold. A secondary pull-down
solenoid is fitted, which operates in
conjunction with the main diaphragm unit to
modify the pull-down characteristics,
improving fuel economy.
61.8 litre models are fitted with an idle cut-off
solenoid. This is an electrically operated valve,
which interrupts the idle mixture circuit when
the ignition is switched off, this preventing
engine “run-on”.13Carburettor - removal,
overhaul and refitting
3
Note: Refer to Section 2 before proceeding.
New gasket(s) must be used when refitting the
carburettor. A tachometer and an exhaust gas
analyser will be required to check the idle
speed and mixture on completion
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 air
box. Extract the three securing screws and lift
off the air box, complete with air trunking.
3On 1.4 litre models, disconnect the fuel
supply hose from the carburettor, and on 1.6
and 1.8 litre models, disconnect the fuel
supply and return hoses from the vapour
separator. Be prepared for fuel spillage, and
take adequate fire precautions. Plug the ends
of the hoses, to prevent dirt ingress and
further fuel spillage.
4Extract the clip from the throttle cable end
fitting at the bracket on the carburettor, then
slide the cable end grommet from the bracket,
and slide the cable end from the throttle valve
lever.
5Disconnect the coolant hoses from the
automatic choke housing noting their
locations, as an aid to refitting. Be prepared
for coolant spillage, and plug the hoses, or
secure them with their ends facing upwards,
to prevent further coolant loss.
6Disconnect the vacuum pipes from the front
of the carburettor, noting their locations and
routing for use when refitting (see
illustration).
7Disconnect the choke heater wire and any
additional wiring.8Unscrew the three securing nuts, and
withdraw the carburettor from the inlet
manifold studs.
9Recover the gasket(s) and insulator block
that fit between the carburettor and the inlet
manifold.
Overhaul
10With the carburettor removed from the
vehicle, drain the fuel from the float chamber
and vapour separator (where applicable).
Clean the outside of the carburettor, then
remove the top cover (Section 15).
11Blow through the jets and drillings with
compressed air, or air from a foot pump - do
not probe them with wire. If it is wished to
remove the jets, unscrew them carefully with
well-fitting tools.
12Remove the fuel filter gauze from the inlet
union, refer to Section 21, for details. Vauxhall
recommend that it is renewed whenever the
carburettor is cleaned.
4A•6Fuel and exhaust systems - carburettor models
12.1B Side view of carburettor, showing automatic choke
housing (1), vapour separator (2) and secondary throttle valve
vacuum diaphragm (3)12.1C Side view of carburettor, showing secondary choke pull-
down solenoid (1) and power valve (2)
13.6 Disconnecting the air box vacuum
pipe from the carburettor - 1.6 litre model
Aerosol cans of carburettor
cleaner are widely available
and can prove useful in
helping to clean internal
passages of stubborn obstructions.

13Clean any foreign matter from the float
chamber. Renew the float, the float needle
valve and seat if wear is evident, or if the float
is punctured or otherwise damaged. Check
that the needle valve closes completely before
the float reaches the top of its movement. See
Section 15, for details of float level checking.
14Renew the diaphragms in the part-load
enrichment valve and in the accelerator pump.
If additional pump or valve parts are supplied
in the overhaul kit, renew these parts also.
15Further dismantling is not recommended.
Pay particular attention to the throttle opening
mechanism arrangement if it is decided to
dismantle it; the interlocking arrangement is
important.
16Reassemble in the reverse order to
dismantling. Use new gaskets and seals
throughout; lubricate linkages with a smear of
molybdenum based grease.
Refitting
17Carry out the following procedure before
refitting.
a)Position the fast idle adjustment screw on
the highest step of the fast idle cam.
b)Use a gauge rod or twist drill of the
specified diameter to measure the
opening of the primary throttle valve.
c)Adjust if necessary at the fast idle
adjustment screw.
d)Note that this is a preliminary adjustment;
final adjustment of the fast idle speed
should take place with the engine running.
18Refitting is a reversal of removal, but
renew the gasket(s).
19After refitting, carry out the following
checks and adjustments.
20Check the throttle cable free play and
adjust if necessary, as described in Section 11.
21Check and if necessary top-up the
coolant level, as described in Chapter 3.
22Check and if necessary adjust the idle
speed and mixture, as described in Section 14.
14Idle speed and mixture -
adjustment
3
Note: Refer to Section 2 before proceeding.
To carry out the adjustments, an accurate
tachometer and an exhaust gas analyser (CO
meter) will be required
1To check the idle speed and mixture
adjustment, the following conditions must be
met:
a)The engine must be at normal operating
temperature
b)All electrical consumers (cooling fan,
heater blower, headlamps, etc.) must be
switched off
c)The ignition timing and spark plug gaps
must be correctly adjusted - see Chapters
1 and 5
d)The throttle cable free play must be
correctly adjusted - see Section 11
e)The air inlet trunking must be free from
leaks, and the air filter must be cleanf)On automatic models, always select
position, “P”.
2Connect a tachometer and an exhaust gas
analyser to the vehicle, according to the
equipment manufacturer’s instructions.
3Start the engine, and run it at 2000 rpm for
approximately 30 seconds, then allow it to
idle. If the idle speed is outside the specified
limits, adjust by means of the throttle stop
screw (see illustration).
4When the idle speed is correct, check the
CO level in the exhaust gas. If it is outside the
specified limits, adjust by means of the idle
mixture adjustment screw. In production, the
screw is covered by a tamperproof plug;
ensure that no local or national laws are being
broken before removing the plug (see
illustration).
5On automatic models, when position “D” is
selected (all electrical systems switched off),
the idle speed should not drop perceptibly. If
it does, the vehicle should be taken to a
Vauxhall dealer for the idle-up system to be
checked using special Vauxhall test
equipment.
6With the idle mixture correct, readjust the
idle speed if necessary.
7If the cooling fan cuts in during the
adjustment procedure, stop the adjustments,
and continue when the cooling fan stops.
8When both idle speed and mixture are
correctly set, stop the engine and disconnect
the test equipment.
9Fit a new tamperproof plug to the idle
mixture adjustment screw, where this is
required by law.
15Needle valve and float -
removal, inspection and
refitting
4
Note: Refer to Section 2 before proceeding. A
new carburettor top cover gasket must be
used on reassembly. A tachometer and an
exhaust gas analyser will be required to check
the idle speed and mixture on completion
Removal
1Disconnect the battery negative lead.
2Remove the round air cleaner, on
applicable models. On other models,
disconnect the air trunking from the air
cleaner, then disconnect the vacuum pipe and
breather hose from the air box. Extract the
three securing screws and lift off the air box,
complete with air trunking.
3Thoroughly clean all external dirt from the
carburettor.
4Disconnect the fuel supply hose at the
carburettor. Be prepared for fuel spillage, and
take adequate fire precautions. Plug the end
of the hose, to prevent dirt ingress and further
fuel spillage.
5Identify the automatic choke coolant hose
locations as an aid to refitting, then
disconnect the hoses. Be prepared for
coolant spillage, and either plug the hoses, or
secure them with their ends facing upwards,
to prevent further coolant loss.
6Disconnect the choke heater wiring plug.
7Disconnect the lower vacuum hoses from
the choke pull-down unit.
8Remove the four carburettor top cover
securing screws, noting their locations, as two
lengths of screw are used (see illustration).
9Lift off the top cover and recover the
gasket.
Inspection
10Hold the cover vertically, so that the float
is hanging from its pivot. Then tilt the cover
until the float needle valve is just closed - the
needle spring must not be compressed by the
weight of the float.
11Measure the distance, dimension x (see
illustration),from the bottom of the float to
the gasket surface on the top cover’s
Fuel and exhaust systems - carburettor models 4A•7
15.8 Carburettor top cover securing
screws (arrowed)14.4 Tamperproof plug (arrowed) covering
idle mixture adjustment screw
14.3 Carburettor idle speed adjustment
(throttle stop) screw (arrowed)
4A

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

4If adjustment is necessary, release the
clamp screw and turn the cam plate in the
desired direction. Tighten the clamp screw,
and recheck the pump delivery (see
illustration).
Removal
5Proceed as described in Section 17,
paragraphs 1 and 2.
6Thoroughly clean all external dirt from the
area around the accelerator pump housing.
7Remove the four securing screws and lift off
the accelerator pump cover. Recover the
diaphragm, spring, valve retainer and valve.
Note the orientation of the valve retainer.
Refitting
8Clean the mating faces of the cover and
housing.
9Check the condition of the valve, and renew
if necessary.
10Begin refitting by locating the valve, valve
retainer and spring in the housing. Note that
the valve retainer can only be fitted in one
position. The larger diameter of the spring
should rest against the valve retainer.
11Locate the diaphragm on the housing,
ensuring that the spring is correctly seated,
and refit the cover. Tighten the cover securing
screws progressively to avoid distorting the
diaphragm (see illustration).
12Further refitting is a reversal of removal.
19Automatic choke unit -
removal, refitting and
adjustment
3
Note: Refer to Section 2 before proceeding. A
tachometer and an exhaust gas analyser will
be required to check the idle speed and
mixture on completion. If the coolant housing
is removed, new O-rings will be required for
refitting
Removal
1Proceed as described in Section 17,
paragraphs 1 and 2.
2Note the position of the bi-metal housing
alignment marks as an aid to refitting, if
necessary making additional marks for clarity,
then remove the three securing screws and lift
off the bi-metal housing. Place the housing to
one side, taking care not to strain the coolant
hoses or electric choke heater wiring.
3Remove the three screws securing the
choke housing to the carburettor body, and
withdraw the choke assembly, taking care not
to bend the choke operating rod.
4If it is necessary to remove the bi-metal
housing for renewal, continue as follows;
otherwise go on to paragraph 8.
5Identify the automatic choke coolant hose
locations as an aid to refitting, then
disconnect the hoses. Be prepared for
coolant spillage, and either plug the hoses, or
secure them with their ends facing upwards,
to prevent further loss of coolant.
6Disconnect the wiring from the electric
choke heater, and withdraw the bi-metal
housing.
7The coolant housing can be separated from
the bi-metal housing by unscrewing the
central securing bolt. Recover the O-rings
from under the bolt head, and from the rim of
the coolant housing.
Refitting
8Begin refitting by locating the choke
assembly on the carburettor body, ensuring
that the lever on the choke assembly engages
with the choke operating rod. Tighten the
three securing screws.
9Check and if necessary adjust the choke
valve gap and the fast idle cam position, as
described in paragraphs 15 to 19, of this
Section.10Connect the bi-metal spring to the choke
lever, position the bi-metal housing on the
choke housing, and loosely fit the securing
screws. Align the marks on the bi-metal
housing and the choke housing as noted
during removal, then tighten the securing
screws.
11Where applicable, refit the coolant
housing to the bi-metal housing, using new O-
rings if necessary, and reconnect the coolant
hoses and electric choke heater wiring.
12Further refitting is a reversal of removal,
remembering the following points.
13If the coolant hoses have been
disconnected, check the coolant level, as
described in Chapter 3.
14Check and if necessary adjust the fast idle
speed, as described in paragraphs 25 to 34,
of this Section.
Adjustment
Choke valve gap
15With the bi-metal housing removed as
described in paragraphs 2 to 4, of this
Section, continue as follows.
16Press the choke operating lever fully
clockwise, and retain it in position with a
rubber band.
17Move the throttle lever to the fully open
position, and measure the choke valve gap
between the lower side of the choke plate and
the wall of the primary barrel. Check that the
gap is as given in the Specifications.
18If necessary, adjust the choke valve gap
by bending the “adjuster segment (2)” If the
gap is too small, enlarge gap “B”, by levering
with a screwdriver. If the gap is too large,
decrease gap “B” using a pair of pliers (see
illustration).
19If no further adjustments are to be carried
out, refit the bi-metal housing, as described in
paragraphs 10 to 14, of this Section.
Fuel and exhaust systems - carburettor models 4A•9
18.11 Carburettor accelerator pump components
1 Cover with operating lever
2 Diaphragm
3 Spring4 Valve
5 Air passage
18.4 Accelerator pump delivery adjustment: “+” to
increase, “-” to reduce
4A

Fast idle cam position
20With the bi-metal housing removed, and
the choke valve gap “B”, correctly set,
continue as follows.
21Open the throttle valve, then close the
choke valve using light finger pressure on the
choke drive lever (see illustration). Close the
throttle valve.
22Check that the fast idle speed adjustment
screw is resting against the stop on the
second highest step of the fast idle cam.
23If adjustment is required, first check that
the choke return spring is correctly
positioned, then adjust by bending the
adjustment lever.
24Refit the bi-metal housing, as described in
paragraphs 10 to 14 of this Section.
Fast idle speed
Note: To carry out the adjustment, an
accurate tachometer and an exhaust gas
analyser (CO meter) will be required
25Check the idle speed and mixture, as
described in Section 14. The idle speed must
be correct before attempting to check or
adjust the fast idle speed.
26With the engine at normal operating
temperature, and a tachometer connected
according to the equipment manufacturer’s
instructions, continue as follows.
27Position the fast idle speed adjustment
screw on the second highest step of the fast
idle cam (see illustration).
28Start the engine without touching the
throttle pedal, and check that the fast idle
speed is as specified. If adjustment is
required, stop the engine and continue as
follows.29Remove the tamperproof cap from the
fast idle speed adjustment screw, ensure that
no local or national laws are being broken by
doing so (see illustration).
30Ensure that the adjustment screw is still
resting on the second highest step of the fast
idle cam, then start the engine, again without
touching the throttle pedal.
31Turn the adjustment screw using a
screwdriver, until the specified fast idle speed
is obtained.
32If the cooling fan cuts in during the
adjustment procedure, stop the adjustments,
and continue when the cooling fan stops.
33On completion of adjustment, stop the
engine and disconnect the tachometer.
34Fit a new tamperproof cap to the fast idle
speed adjustment screw, where this is
required by law.
20Automatic choke vacuum
pull-down units - removal,
refitting and adjustment
3
Main diaphragm unit
Note: Refer to Section 2 before proceeding. A
new star clip must be used when refitting the
diaphragm unit. Test vacuum units as
described in Section 16, paragraph 1.
Removal
1Proceed as described in Section 17,
paragraphs 1 and 2.
2Disconnect the diaphragm unit vacuum
pipes.
3Using a pin punch, tap out the roll pin
securing the diaphragm unit to the carburettor
top cover.
4Note the position of the bi-metal housing
alignment marks as an aid to refitting, if
necessary making additional marks for clarity,
then remove the three securing screws, and
lift off the bi-metal housing. Place the housing
to one side, taking care not to strain the
coolant hoses or electric choke heater wiring.
4A•10Fuel and exhaust systems - carburettor models
19.18 Choke valve gap adjustment
1 Choke operating lever
2 Adjuster segment
B Choke valve gap
19.21 Fast idle cam adjustment
1 Fast idle cam
2 Adjustment lever
3 Choke drive lever
4 Fast idle speed adjustment screw
19.29 Tamperproof cap (arrowed) fast idle speed adjustment
screw19.27 Fast idle speed adjustment
3 Fast idle speed adjustment screw
4 Screw positioned on second highest step of cam

5Remove the three screws securing the
choke assembly to the carburettor body.
Allow the choke assembly to drop down, but
do not disconnect the choke linkage.
6Remove the star clip that secures the
diaphragm unit to the carburettor top cover,
and withdraw the diaphragm unit.
Refitting
7Refitting is a reversal of removal, but use a
new star clip to secure the diaphragm unit to
the carburettor top cover. Before refitting the
air box to the top of the carburettor, check
and if necessary adjust the choke pull-down,
as follows.
Vacuum pull-down
Adjustment
8With the air cleaner or air box removed from
the top of the carburettor, as described in
Section 17, paragraph 2, continue as follows.
9Note the position of the bi-metal housing
alignment marks as an aid to refitting, if
necessary making additional marks for clarity,
then remove the three securing screws, and
lift off the bi-metal housing. Place the housing
to one side, taking care not to strain the
coolant hoses or electric choke heater wiring.
10Position the fast idle speed adjustment
screw on the highest step of the fast idle cam,
and check that the choke valve is closed.
11Move the pull-down arm towards the
diaphragm unit by pushing on the adjustment
screw until resistance is felt. Hold the arm in
this position.
12Using a drill shank of appropriate
diameter, or a similar item, measure the
clearance between the lower side of the
choke plate and the wall of the primary barrel
(see illustrations). Check that the clearance
is as given for the “small” choke pull-down
gap in the Specifications.
13If adjustment is necessary, turn the
adjustment screw in the appropriate direction,
using an Allen key, until the clearance is
correct.14Now push the pull-down arm towards the
diaphragm unit as far as its stop, and hold the
arm in this position.
15As before measure the clearance between
the lower side of the choke plate and the wall
of the primary barrel. Check that the
clearance is as given for the “large” choke
pull-down gap in the Specifications.
16If adjustment is necessary, turn the
adjustment screw in the appropriate direction
until the clearance is correct.
17Connect the bi-metal spring to the choke
lever, position the bi-metal housing on the
choke housing and loosely fit the securing
screws. Align the marks on the bi-metal
housing and the choke housing as noted
during removal, then tighten the securing
screws.
18Refit the air box to the top of the
carburettor on completion.
Secondary pull-down solenoid
Removal
19This unit operates in conjunction with the
main diaphragm unit.
20To remove the solenoid unit, first continue
as described in Section 17, paragraphs 1 and
2.
21Disconnect the diaphragm unit vacuum
pipe.22Disconnect the wiring plug, then unscrew
the securing screw, and withdraw the
solenoid unit and its mounting bracket from
the carburettor. Note that the securing screw
also secures the wiring plug earth lead (see
illustration).
Refitting
23Refitting is a reversal of removal, but
ensure that the wiring plug earth lead is in
place under the solenoid bracket securing
screw.
21Carburettor filter -removal
and refitting
3
Removal
1A small tubular filter gauze is fitted into the
carburettor top cover’s fuel inlet union to
remove any particles of dirt from the fuel.
2To ensure a clean fuel supply and to
prevent the risk of misfiring, poor starting or
other problems due to a restricted fuel supply,
this filter must be cleaned and/or renewed at
the interval specified in Chapter 1.
3To reach the filter, remove the air cleaner or
air box, as applicable, then disconnect and
plug the hose from the fuel pump or vapour
separator to the top cover union.
4Remove the filter by hooking it out with a
small screwdriver, or by snaring it with a long
thin screw (3 mm thread size, screwed
approximately 5 mm into the filter).
5If the filter is blocked or heavily fouled, or if
it is torn, distorted or damaged in any way, it
must be renewed. If it is fit for further use,
clean it using a jet of compressed air or by
brushing away particles of dirt with an old soft
toothbrush. Then flushing it in clean solvent,
taking care not to allow any overspray to get
into your eyes; if petrol is used, take care to
prevent the risk of fire.
Fuel and exhaust systems - carburettor models 4A•11
20.12B Checking the vacuum pull-down gap using a twist drill
20.22 Secondary choke pull-down
solenoid securing screw and earth lead
20.12A Choke vacuum pull-down adjustment
1 Adjustment screw 2 Diaphragm unit A Twist drill
4A

Refitting
6On refitting the filter, press it into the union
until it catches (see illustration). The
remainder of the reassembly procedure is the
reverse of removal.
22Throttle valve dashpot
(automatic models) -
adjustment
2
1Remove the air cleaner or air box, refer to
Section 3.
2Ensure that the lever (see illustration)is in
the idling position.
3Slacken the locknut and unscrew the
dashpot until a gap of 0.05 mm (0.002 in)
exists between the lever and the dashpot tip.
Then screw the dashpot downwards 2.5 full
turns and tighten the locknut.
4Refit all removed components.
23Throttle position sensor
(automatic transmission
models) - removal and refitting
2
Removal
1Disconnect the battery earth lead.
2Disconnect the wiring plug from the sensor.
3Either unscrew the two securing screws
and withdraw the sensor from its bracket, or
unbolt the bracket.
Refitting
4Refitting is the reverse of the removal
procedure, noting the following points.
a)Install the sensor when the throttle valve
is fully closed and ensure that the
adapter, “1” (see illustration),seats
correctly on the throttle valve spindle.
b)Tighten the screws carefully.
24Idle speed increase valve -
testing
2
1Certain models are fitted with an idle speed
increase valve that is attached to the side of
the carburettor.
2To test the operation of this valve first
remove the air filter and vacuum hose.
3With the valve’s plug connected, have
someone turn the ignition on (but do not start
the engine). A mechanical shifting noise
should be heard. If not replace the unit.
4After refitting replace the vacuum hose and
air filter.
25Idle cut-off solenoid (1.8 litre
models) - description and
testing
2
Note: Refer to Section 2 before proceeding
Description
1On 1.8 litre models, the carburettor is fitted
with an idle cut-off solenoid. This is an
electrically operated valve, which interrupts
the idle mixture circuit when the ignition isswitched off, thus preventing the engine from
running-on (see illustration).
2The idle cut-off solenoid is energised all the
time that the ignition is switched on. A
defective solenoid, or a break in its power
supply, will cause the engine to stall or idle
roughly, although it will run normally at speed.
Testing
3If the operation of the solenoid is suspect,
first check that battery voltage is present at
the solenoid terminal when the ignition is
switched on. Use a 12 volt test lamp or similar
test device.
4If no voltage is present, then the fault lies in
the wiring to the solenoid. If voltage is
present, the solenoid can be tested as
follows.
5With the solenoid unscrewed from the
carburettor, connect the body of the solenoid
to the negative terminal of a 12 volt battery.
When the battery positive terminal is
connected to the solenoid centre terminal,
there should be an audible click, and the
needle at the tip of the solenoid should
retract.
6A defective idle cut-off solenoid must be
renewed.
26Inlet manifold - removal and
refitting
3
Note: Refer to Section 2 before proceeding. A
new manifold gasket must be used on refitting
Removal
1Disconnect the battery negative lead.
2Drain the cooling system, as described in
Chapter 3.
3Proceed as described in Section 13,
paragraphs 2 to 7 inclusive, ignoring the
reference to coolant spillage in paragraph 5.
4A•12Fuel and exhaust systems - carburettor models
21.6 Refitting the carburettor fuel filter
23.4 Throttle position sensor - models with automatic
transmission
1 Adapter 2 Sensor22.2 Adjusting the throttle valve dashpot - models with
automatic transmission
1 Lever2 Locknut3 Dashpot

4Disconnect the coolant hose from the rear
of the manifold (see illustration).
5Where applicable, disconnect the camshaft
cover breather hose from the rear of the
manifold (see illustration).
6Unscrew the union and disconnect the
brake servo vacuum hose from the manifold.
7On 1.4 and 1.6 litre models, disconnect the
wiring from the temperature gauge sender.
8Unscrew and remove the top alternator
mounting nut and bolt.
9On 1.4 and 1.6 litre models, disconnect and
remove the stub hose that connects the
crankcase breather tube to the rear of the
camshaft housing.
10Make a final check to ensure that all
relevant hoses, pipes and wires have been
disconnected.
11Unscrew the securing nuts, and withdraw
the manifold from the cylinder head (see
illustration). Note the position of the rear
engine lifting bracket, which is secured by one
of the manifold nuts, and recover the manifoldgasket.
12It 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.
13If desired, the carburettor can be removed
from the manifold, referring to Section 13, if
necessary.
Refitting
14Refitting is a reversal of removal,
remembering the following points.
15If the carburettor has been removed from
the manifold, refit it, using a new gasket.
16If the alternator mounting bracket has
been unbolted from the manifold, refit it
before refitting the manifold, as access to the
securing bolt is extremely limited once the
manifold is in place.
17Refit the manifold using a new gasket,and ensure that the engine lifting bracket is in
place under the relevant manifold nut. Tighten
the nuts to the specified torque.
18Ensure that all relevant hoses, pipes and
wires are correctly reconnected.
19Refill the cooling system, as described in
Chapter 3.
20Check the throttle cable free play and
adjust if necessary, as described in Section
11.
21If the carburettor has been disturbed,
check and if necessary adjust the idle speed
and mixture, as described in Section 14.
Fuel and exhaust systems - carburettor models 4A•13
26.5 . . .and the camshaft cover breather
hose (arrowed) from the inlet manifold -
1.6 litre model
26.11 Withdrawing the inlet manifold -
1.6 litre model
26.4 Disconnecting the coolant hose . . .
4A
25.1 Carburettor idle cut-off solenoid
(arrowed) - 1.8 litre models