light FIAT UNO 1983 Service User Guide
[x] Cancel search | Manufacturer: FIAT, Model Year: 1983, Model line: UNO, Model: FIAT UNO 1983Pages: 303, PDF Size: 10.36 MB
Page 39 of 303

8Fit the new belt. Start at the crankshaft
drive pulley and, taking care not to kink or
strain the belt, slip it over the camshaft pulley.
The camshaft may have to be turned slightly
to mesh the pulley with the teeth on the belt.
Fit the belt on the tensioner pulley last; if this
is difficult, do not lever or force the belt on,
recheck the belt (photo).
9Release the tensioner nut and rotate the
crankshaft through two complete revolutions.
Retighten the nut. The belt tension may be
checked by twisting it through 90º with the
finger and thumb. It should just turn through
this angle without undue force. Note: The
above procedure serves only as a rough guide
to setting the belt tension - having it checked
by a FIAT dealer at the earliest opportunity is
recommended.
10Refit the timing belt cover (photo). Fit and
tension the alternator drivebelt (Chapter 2,
Section 8).
29 Cylinder head-
removal and refitting
3
1Drain the cooling system (see Chapter 2).
2Disconnect the battery.
3Disconnect and plug the carburettor fuel
hoses.
4Disconnect the throttle and choke linkage
from the carburettor. 5Disconnect the HT leads from the spark
plugs.
6Disconnect the brake servo vacuum hose
from the intake manifold.
7Disconnect the coolant hoses from the
thermostat housing.
8Disconnect the crankcase ventilation
system hoses from the rocker cover and
carburettor.
9Unbolt and remove the timing belt cover.
10Release the timing belt tensioner pulley
bolt, then lever the pulley against the spring
plunger and retighten the bolt to retain the
tensioner pulley in the non-tensioned position.
Slip the belt from the camshaft sprocket.
11Disconnect the coolant hoses from the
carburettor and intake manifold.
12Disconnect the exhaust downpipes from
the manifold.
13If a crowfoot type wrench is available, the
cylinder head nuts and bolts can be removed
and the complete cylinder head camshaft
carrier assembly withdrawn (photo).
14If this type of wrench is not available
however, remove the carrier first as described
in Section 27.
15If a crowfoot is available, unscrew the
cylinder head nuts and bolts evenly and
progressively starting with the centre ones
and working towards both ends.
16Rock the cylinder head by gripping the
manifolds. Note: Do not insert a lever in
the gasket joint to prise the head from the
block.17Pull the head off the studs and remove it
to the bench. Remove and discard the old
cylinder head gasket.
18Unbolt and remove the hot air collecting
shield for the air cleaner from the exhaust
manifold. The exhaust and inlet manifolds can
now be unbolted. The carburettor may remain
on the inlet manifold.
19Overhaul and decarbonising of the
cylinder head is described in Section 39.
20Refitting is a reversal of the removal
process, but make sure the crankshaft and
camshaft timing marks are set as described in
Section 28 to avoid the valve heads digging
into the piston crowns when the head is
refitted.
21Always use new gaskets. The cylinder
1116 cc and 1301 cc engine 1•25
Fig. 1.29 Timing belt arrangement (Sec 28)
1 Camshaft sprocket
2 Tensioner pulley locknut
3 Timing mark on crankshaft front oil seal
retainer
4 Crankshaft sprocket
5 Crankshaft sprocket timing mark
6 Auxiliary shaft sprocket
7 Tensioner bracket bolt
8 Tensioner pulley
9 Timing belt
10 Tensioner bracket
11 Tensioner spring
28.8 Slipping timing belt onto tensioner
pulleyFig. 1.28 TDC marks (1) at front of engine
(Sec 28)
Fig. 1.30 Cylinder head bolt tightening
sequence (Sec 29)28.10 Tightening timing belt cover nut29.13 Using a crowfoot type wrench on a
cylinder head bolt
1
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2The big-end bearing shells can be renewed
without having to remove the cylinder head if
the caps are unbolted and the
piston/connecting rod pushed gently about
one inch up the bore (the crankpin being at its
lowest point). If these shells are worn,
however, the main bearing shells will almost
certainly be worn as well. In this case, the
engine should be removed for complete
overhaul including crankshaft removal.
3To remove the piston/connecting rods,
remove the cylinder head as described in
Section 29.
4Grip the oil pick-up pipe and twist or rock it
from its hole in the crankcase. It is an
interference fit in the hole.
5Unscrew the nuts from the big-end caps,
then remove the caps with their bearing
shells. The caps and their connecting rods are
numbered 1, 2, 3 and 4 from the timing cover
end of the engine. The numbers are adjacent
at the big-end cap joint and on the side of the
crankcase furthest from the auxiliary shaft.
6If the bearing shells are to be used again,
tape them to their respective big-end caps.
7Push each connecting rod/piston assembly
up the bore and out of the cylinder block.
There is one reservation; if a wear ridge has
developed at the top of the bores, remove this
by careful scraping before trying to remove
the piston/rod assemblies. The ridge will
otherwise prevent removal or break the piston
rings during the attempt.
8If the connecting rod bearing shells are to
be used again, tape the shells to their
respective rods.
9Dismantling the piston/connecting rod is
described in Section 18.
Refitting
10Fit the new shells into the connecting rod
and caps, ensuring the surfaces on which the
shells seat, are clean and dry.
11Check that the piston ring gaps are evenly
spaced at 120º intervals. Liberally oil the rings
and the cylinder bores.
12Fit a piston ring clamp to compress the
rings.
13Insert the piston/connecting rod into the
cylinder bore, checking that the rod assembly
is correct for that particular bore. The cap and
rod matching numbers must be furthest away
from the auxiliary shaft (Fig. 1.31).14Push the piston into the bore until the
piston ring clamp is against the cylinder block
and then tap the crown of the piston lightly to
push it out of the ring clamp and into the bore
(photo).
15Oil the crankshaft journal and fit the
big-end of the connecting rod to the journal.
Fit the big-end cap and nuts, checking that
the cap is the right way round (photo).
16Tighten the big-end nuts to the specified
torque. The correct torque is important as the
nuts have no locking arrangement. After
tightening each big-end, check the crankshaft
rotates smoothly (photo).
17Refit the oil pick-up pipe, the cylinder
head, oil pump and sump pan, all as
described earlier.
18Refill the engine with oil and coolant.
33 Engine mountings-
renewal
1
1Three engine/transmission flexible
mountings are used.
2To renew a mounting, support the weight of
the engine/transmission on a hoist or jack and
unbolt and remove the mounting.
3In the unlikely event of all three mountings
requiring renewal at the same time, only
disconnect them and renew them one at a
time.
34 Engine- method of removal
1The engine complete with transmission
should be removed by lowering it to the floor
and withdrawing it from under the front of the
car which will have been raised to provide
adequate clearance.
35 Engine/transmission-
removal and separation
3
1Open the bonnet, disconnect the
windscreen washer tube.
2Mark the hinge positions on the undersideof the bonnet and then with the help of an
assistant to support its weight unbolt and
remove the bonnet to a safe place.
3Disconnect the battery negative lead.
4Drain the cooling system and the engine
and transmission oils.
5Remove the air cleaner.
6From the rear of the alternator disconnect
the electrical leads.
7Disconnect the leads from the starter
motor, oil pressure and coolant temperature
switches, also the oil temperature switch.
8Disconnect the LT lead from the distributor
and the HT lead from the ignition coil.
9Disconnect the clutch cable from the
release lever at the transmission. Also
disconnect the speedometer drive cable
(knurled ring).
10Pull the leads from the reversing lamp
switch.
11Disconnect all coolant hoses from the
engine. Also disconnect the brake servo hose
from the intake manifold.
12Disconnect the choke and throttle
controls from the carburettor.
13Disconnect the inlet hose from the fuel
pump and plug the hose.
14Disconnect the fuel return hose from the
carburettor.
15Disconnect the coolant hoses from the
carburettor throttle block.
16Raise the front of the car and remove the
front roadwheels.
17Unscrew and remove the driveshaft to
hub nuts. These are very tight and a long
knuckle bar will be required when unscrewing
them. Have an assistant apply the brake pedal
hard to prevent the hub from turning.
18Working under the car, remove the inner
wing protective shields and then disconnect
the exhaust downpipe from the manifold.
19Disconnect the exhaust pipe sections by
removing the socket clamp just forward of the
rear axle beam. Remove the front section.
20Disconnect the forward ends of the
gearchange rods by prising their sockets from
the ballstuds.
21Unscrew the nuts on the steering tie-rod
end balljoints and then using a suitable
“splitter” tool, separate the balljoints from the
steering arms.
22Unbolt the front brake hose support clips
1116 cc and 1301 cc engine 1•27
32.16 Tightening a big-end cap nut32.15 Fitting a big-end cap32.14 Fitting piston into cylinder bore
1
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6Remove the spring seat (photo).
7Discard the valve stem oil seal and fit a new
one (photo).
8Remove the remaining valves in a similar
way and keep the components in their
originally fitted sequence.
9Reassembly is a reversal of removal. Refit
the components to their original positions, but
renew the valve springs if their free length is
less than that of a new spring or if the
springs have been in operation for more than
80 000 km (50 000 miles).
10The original valve clearance adjusting
shims will no longer provide the correct
clearances if the valves have been ground in
or the seats recut. Only where dismantling of
a valve was carried out to renew a spring is
there any purpose in returning the shims to
their original locations. Try to obtain the loan
of eight thin shims from your dealer and insert
them into the tappets (cam followers) before
assembling the cam followers to the carrier,
where they should be retained with thick
grease (photo).
11Fit the camshaft carrier, complete with
cam followers and shims to the cylinder head.
12Adjust the valve clearances as described
in Section 26.
40 Examination and renovation
4
1The procedures are similar to those
described in Section 18 covering the
following:
Cylinder block and crankcase
Crankshaft and bearings
Pistons and piston rings
Flywheel
2The following additional items must also be
examined.
Oil pump
3Carefully, clamp the pump housing in a
vice, shaft downwards.
4Take off the pump cover, with the suction
pipe. This will release the oil pressure relief
valve inside. Also inside is a filter.
5Remove the internal cover plate.6Take out the driveshaft and the gears.
7Clean and examine all the parts. Measure
the clearances against the Specifications. The
end clearance is measured by putting a
straight-edge across the cover face.
8The oil pump should only need
replacements after very long mileage, when
the rest of the engine is showing great signs
of wear.
9The length of a new gear can be measured
against the old gear to see if a new gear will
restore the end clearance to the Specifica-
tions. Otherwise the housing must be
changed.
10The driven gear shaft is mounted in the
housing with an interference fit. If there is any
slackness, a new housing (which will come
with shaft fitted) must be used.
11The oil pump shares its drive with the
distributor.
Camshaft, cam followers and
shims
12The camshaft journals and cams should
be smooth, without grooves or scores.
13Wear in the camshaft carrier bearings can
only be rectified by renewal of the carrier.
14Cam follower wear is usually very small
and when they show slackness in their bores,
it is probably the light alloy of the camshaft
carrier which has worn.
15Always measure the thickness of the valve
clearance shims using a metric micrometer.
Any grooving or wear marks in the shims
should be rectified by renewal with ones of
similar thickness.
Auxiliary shaft
16The shaft journals, the fuel pump
eccentric, and the drivegear for the distributor
and oil pump should be smooth and shiny. If
not, the shaft will have to be renewed.
17The bushes should still be tight in the
cylinder block, their oil holes lined up with
those in the block.
18Measure the bearing clearance. If
excessive, the bushes will have to be
renewed. They are a press fit, and require
reaming with a special reamer after fitting.
This is a job best done by a Fiat agent with the
special tools.
19Ensure the new bushes are fitted with the
oil holes lined up.
20Also check the driven gear and its bush.
21It is recommended a new oil seal is fitted
in the endplate. Hold the shaft in a vice, and
remove the pulley. Fit the new oil seal in the
endplate, lips inwards.
Timing belt tensioner
22Check the bearing revolves smoothly and
freely, and has no play. Do not immerse it in
cleaning fluid, as it is partially sealed. Wipe
the outside, and then smear in some new
general purpose grease.
23The action of the spring will have been felt
when the belt was taken off. It should be
cleaned, and oiled, to prevent seizure through
dirt and rust.
24Note the circlip on the engine right-hand
mounting bracket. This retains the timing belt
tensioner plunger.
1116 cc and 1301 cc engine 1•29
39.6 Valve spring seat39.5 Removing a valve39.4B Double valve springs
39.10 Cam followers fitted to camshaft
carrier39.7 Valve stem oil seal
1
Page 48 of 303

to the engine. Also reconnect the brake servo
hose to the intake manifold (photos).
22Reconnect the leads to the reversing lamp
switch. Reconnect the transmission earth lead
(photos).
23Reconnect the clutch cable and adjust as
described in Chapter 5.
24Reconnect the speedometer drive cable
to the transmission and tighten the knurled
retaining ring.
25Reconnect the low tension lead to the
distributor and the high tension lead to the
ignition coil.
26Reconnnect the electrical leads to thestarter motor, the oil pressure and
temperature switches and the coolant
temperature switch.
27Connect the leads to the alternator.
28Refit the air cleaner.
29Refill the cooling system. Refill the engine
with oil.
30Reconnect the battery.
31Refit the bonnet and connect the
windscreen washer tube.
32Fit the inner wing protective shields
(photo).
45 Engine- initial start-up after
major overhaul
4
1If new bearings and rings have been fitted,
it is likely that the engine will be stiff to turn so
make sure the battery is well charged.
2Switch on the ignition and check that
appropriate warning lights come on.
3Start up the engine. If it refuses to start,
refer to the “Fault Finding” Section in the
Reference section of this Manual.
4Watch the oil pressure warning light and
alternator charging indicator light. If there is
no charge or if the oil pressure warning light
does not go out after a second or two, havinghad time to fill the new oil filter, switch off and
recheck.
5If the warning lights go out, set the engine
to run on fast idle and check the engine for
leaks.
6Check the coolant level; it will probably go
down as air locks are filled.
7Keep the engine running at a fast idle and
bring it up to normal working temperature. As
the engine warms up, there will be some odd
smells and smoke from parts getting hot and
burning off oil deposits.
8When the engine running temperature has
been reached, adjust the idling speed, as
described in Chapter 3. Check and, if
necessary, adjust the ignition timing using a
stroboscope (see Chapter 4).
9Stop the engine and wait a few minutes;
check to see if there are any coolant or oil
leaks.
10Road test the car to check that the engine
is running with the correct smoothness and
power. If it does not, refer to “Fault finding” in
the Reference section of this Manual. Do not
race the engine. If new bearings and/or
pistons and rings have been fitted, it should
be treated as a new engine and run it at
reduced speed for at east 800 km (500 miles).
11After 800 km (500 miles) change the
engine oil and filter.
1•34 1116 cc and 1301 cc engine
44.32 Inner wing protective shield44.26B Coolant temperature switch44.26A Oil pressure warning switch
44.22B Transmission earth lead
44.22A Reversing lamp switch on
transmission44.21B Brake servo hose at manifold44.21A Heater hose at manifold
Page 50 of 303

Engine idles roughly
m mMixture too weak
m mAir leak in carburettor
m mAir leak at inlet manifold to cylinder head, or inlet manifold to
carburettor
m mCarburettor incorrectly adjusted
m mOther fuel system fault (see Chapter 3)
m mLow tension leads on coil loose
m mLow tension lead to distributor loose
m mDirty, incorrectly set, or pitted contact breaker points
m mTracking across inside of distributor cover
m mFaulty coil
m mIgnition leads loose
m mSpark plugs fouled or incorrectly gapped.
m mIgnition timing incorrect
m mOther ignition fault (see Chapter 4)
m mIncorrect valve clearances
m mWidely differing cylinder compressions
m mLow battery voltage (charging fault)
m mBattery leads loose on terminals
m mBattery earth strap loose on body attachment point
m mEngine earth lead loose
Pre-ignition (pinking) during acceleration
m
mIncorrect grade of fuel being used
m mIgnition timing over-advanced
m mOther ignition fault (see Chapter 4)
m mEngine overheated
m mExcessive carbon build-up
m mFuel system fault (see Chapter 3)
m mValve timing incorrect (after rebuild)
m mMixture too weak
Engine runs on after switching off
m
mIdle speed too high
m mIncorrect type of spark plug
m mOverheating
m mExcessive carbon build-up
m mOther emission control fault (see Chapter 3)
Oil being lost due to leaks
m
mLeaking oil filter gasket
m mLeaking rocker cover gasket
m mLeaking timing gear cover gasket
m mLeaking sump gasket
m mLoose sump plug
Low oil pressure (verify accuracy of sender before
dismantling engine!)
m mOil level low
m mEngine overheating
m mIncorrect grade of oil in use
m mOil filter clogged or bypass valve stuck
m mPressure relief valve stuck or defective
m mOil pick-up strainer clogged or loose
m mMain or big-end bearings worn
m mOil pump worn or mountings loose
Excessive oil consumption
m
mOverfilling
m mLeaking gaskets or drain plug washer
m mValve stem oil seals worn, damaged or missing after rebuild
m mValve stems and/or guides worn
m mPiston rings and/or bores worn
m mPiston oil return holes clogged
Oil contaminated with water
m
mExcessive cold running
m mLeaking head gasket
m mCracked block or head
Oil contaminated with fuel
m
mExcessive use of choke
m mWorn piston rings and/or bores
Unusual mechanical noises
m
mUnintentional mechanical contact (eg fan blade)
m mWorn drivebelt
m mWorn valvegear (tapping noises from top of engine) or incorrect
clearance
m mPeripheral component fault (generator, coolant pump)
m mWorn big-end bearings (regular heavy knocking, perhaps less under
load)
m mWorn main bearings (rumbling and knocking, perhaps worsening
under load)
m mSmall-end bushes or gudgeon pins worn (light metallic tapping)
m mPiston slap (most noticeable when engine cold)
m mWorn timing chain and gears (rattling from front of engine)
m mWorn crankshaft (knocking, rumbling and vibration)
1•36 All engines
Page 53 of 303

inhibitor should be used. Again, a reputable
make giving full protection must be chosen
and renewed every two years. Inhibitors with
dyes are useful for finding leaks, and on some
makes the dye shows when the inhibiting
ability is finished.
4 Thermostat-
removal, testing and refitting
1
1The thermostat assembly is mounted on the
flywheel end of the cylinder block.
2Unfortunately, the thermostat/housing is a
complete unit and failure of the thermostat will
necessitate the purchase of the complete
component (photo).
3If the thermostat/housing is removed from
the engine, it can be suspended in water and
the water heated to check out its opening
temperature. Movement of the thermostat
valve can be observed to some extent
through the openings in the housing.
4When refitting, always use a new gasket at
its mounting face (photo).
5 Radiator fan thermostatic
switch- removal, checking
and refitting
1
1Drain the cooling system.
2If the thermostatic switch is being removed
because the fan is not operating and the
switch is suspect, check the fan fuse first,
before removing the switch.3To remove the switch, disconnect the leads
from the terminals and unscrew the switch.
4Connect a test bulb and battery across the
switch terminals and then immerse the
sensing part of the switch in a container of
water. Heat the water and, using a
thermometer, check the temperature of the
water when the bulb lights up, indicating the
switch is functioning. The switch should
operate at approximately 194ºF (90ºC). Allow
the water to cool and check that the switch
cuts out at 185ºF (85ºC). Renew a faulty
switch.
5Refitting of the switch is the reverse of the
removal procedure. Always fit a new O-ring on
the switch.
6 Radiator fan-
removal and refitting
1
1Disconnect the electrical leads from the
radiator fan motor.
2Unbolt the fan mounting struts from the
radiator and lift the complete assembly away.
3Refitting is a reversal of removal.
7 Radiator-
removal and refitting
1
1Drain the cooling system.
2Disconnect the electrical leads from the
radiator fan motor and thermostatic switch.3Disconnect the coolant hoses from the
radiator (photos).
4Release the clips from the top of the
radiator and withdraw the radiator complete
with fan from the engine compartment
(photos).
5The radiator is of combined plastic/metal
construction and any repair should be left to
specialists. In an emergency however, minor
leaks from the radiator may be cured by using
a radiator sealant with the radiator in situ.
6Refitting is a reversal of removal. Fill the
cooling system as described in Section 2.
8 Drivebelt-
tensioning and renewal
1
1The drivebelt for the alternator and coolant
pump is correctly tensioned if it deflects
through 10.0 mm (0.39 in) under moderate
thumb pressure at the mid point of the longest
run of the belt.
2To tighten the belt, release the mounting
and adjuster nuts on the alternator and prise
the alternator away from the engine. Tighten
the nuts when the belt is taut and then
re-check the tension as previously described.
Never over-tension a belt or the coolant pump
or alternator bearings may be damaged.
3Check the condition of the belt at regular
intervals. If frayed or cracked, renew it in the
following way.
4Release the alternator mounting and
adjuster nuts and push the alternator fully in
Cooling and heating systems 2•3
7.3A Radiator top hose4.4 Fitting thermostat housing
(1116 cc engine)4.2 Thermostat housing
7.4B Removing radiator/fan assembly7.4A Radiator fixing clip7.3B Radiator hose to thermostat housing
2
Page 56 of 303

5Pull off the knobs from the control levers
(photo).
6Extract the screws and take off the control
indicator plate (photos). Disconnect the leads
from the cigar lighter and carefully detach the
fibre optic which provides the panel
illumination.
7Unscrew and remove the screws which
hold the console to the heater unit and
withdraw the console.
8The control cables can be disconnected
from the arms of the control flap valves
(photos).
9Unscrew the single screw from the upper
face of the facia panel. This screw secures theupper part of the heater casing (photo).
10Unscrew the mounting nuts which hold
the heater to the bulkhead (photo).
11Lower the heater to the floor, taking care
not to allow coolant to spill on the carpet.
12Refitting is a reversal of removal. Fill the
cooling system.
13 Heater- dismantling, overhaul
and reassembly
1
1Remove the heater from the car as
described in the preceding Section.
2•6 Cooling and heating systems
Fig. 2.10 Withdrawing heater matrix
(Sec 13)Fig. 2.9 Control lever platform screw
(Sec 13)12.10 Heater lower mounting bolt
12.9 Heater upper fixing screw
12.8A Heater coolant valve and control
cable
Fig. 2.8 Extracting heater upper fixing
screw (Sec 12)12.8B Heater flap valve cables
12.6B Removing heater control panel
escutcheon12.6A Heater control panel screw12.5 Pulling off heater control lever knob
Page 69 of 303

Anti-flooding device (automatic)
10Pull the choke control fully out and hold the
control lever, on the anti-flooding device,
depressed. There should be a gap (Y)
(Fig. 3.27) between the edge of the choke valve
plate and the carburettor wall of between 3.75
and 4.25 mm (0.15 and 0.17 in). If adjustment is
required, turn the adjuster screw provided.
15 Carburettor
(Solex C30-32 (CIC/1)-
servicing and adjustment
4
1The carburettor top cover with float may be
removed without the need to withdraw the
carburettor from the manifold.
2The other adjustments described in this
Section will require removal of the carburettor.
3Extract the top cover fixing screws and lift
away the top cover with float.
4Refer to Section 9 paragraphs 4 and 5 for
details of removal of the fuel inlet needle
valve.
Float adjustment
5Invert the carburettor cover so that theweight of the floats depresses the ball of the
needle valve.
6Measure the distance between the float and
the surface of the cover gasket. This should
be between 6.5 and 7.5 mm (0.26 and 0.30 in).
If adjustment is required, change the
thickness of the needle valve washer or
carefully bend the float arm.
Accelerator pump
7Refer to Section 10, paragraphs 6 and 7.
The total volume of fuel collected should be
between 7.5 and 9.5 cc. If the volume of fuel
is incorrect, release the locknut and turn the
adjuster screw on the pump lever then re-test
the volume ejected.
Fast idle
8Operate the choke control lever to close the
choke valve plate. The gap between the edge
of the primary throttle valve plate and the
venturi wall should be between 0.90 and
1.00 mm (0.035 and 0.039 in). If adjustment is
required, turn the nut on the fast idle rod.
Automatic anti-flooding device
9The vacuum system of the device can be
checked for leaks by applying a vacuum to
the drilling in the carburettor throttle valve
block. If vacuum cannot be maintained, renew
the diaphragm.
Choke valve plate automatic
opening
10Move the choke control lever to fully close
the choke valve plate and then press the lean
out valve rod. There should now be a gap (X)
(Fig. 3.32) between the edge of the choke
valve plate and the wall of the carburettor
throat of between 4.75 and 5.25 mm (0.187
and 0.207 in).
11Where adjustment is required, release the
locknut and turn the screw on the lean out
valve.
16 Economy meter
1This device is fitted to ES (energy saving)
models. It is essentially a vacuum gauge to
advise the driver with regard to economical
throttle opening related to engine and road
speed. The point of change to a higher gear
can also be deduced from this gauge. The
latter facility is provided by an LED (light
emitting diode).
2Fault testing of the system is described in
Chapter 9.
Fuel system 3•11
Fig. 3.29 Adjusting accelerator pump
stroke (Solex C30-32 CIC/1) (Sec 15)Fig. 3.28 Float setting diagram
(Solex C30-32 CIC/1) (Sec 14)
A = 6.7 to 7.5 mm (0.26 to 0.30 in)
Fig. 3.32 Choke valve plate setting
(Solex C30-32 CIC/1) (Sec 15)
X = 4.75 to 5.25 mm (0.187 to 0.207 in)Fig. 3.30 Fast idle screw on
Solex C30-32 CIC/1 (Sec 15)
A Choke control lever C Lean out valve
B Fast idle adjustmentFig. 3.31 Vacuum drilling for automatic
anti-flooding device (Solex C30-32 CIC/1)
(Sec 15)
3
Fig. 3.27 Anti-flooding device (automatic)
adjustment diagram
(Weber 30/32 DMTR 90/250) (Sec 14)
Y = 3.75 to 4.25 mm (0.148 to 0.167 in)
Page 70 of 303

19.7A Exhaust pipe support rings
17 Accelerator cable-
adjustment and renewal
2
1The socket type cable end fitting is
detached from the carburettor throttle lever
simply by prising it off the ball stud.
2Adjustment can be carried out by releasing
the locknut and turning the end fitting. With
the accelerator pedal fully depressed, check
that full throttle can be obtained at the
carburettor.
3To renew the cable, prise off the end fitting
from the carburettor throttle lever.
4Slip the cable sleeve from its retaining
bracket (photo).
5Working inside the car under the facia
panel, slip the cable from the fork at the top of
the accelerator pedal arm (photo). 6Withdraw the cable through the engine
compartment bulkhead.
7Fit the new cable by reversing the removal
operations, adjust as described in para-
graph 2.
18 Choke control cable-
removal and refitting
2
1Remove the air cleaner.
2Release the choke outer cable clamp and
the inner cable from the swivel on the choke
control lever (photo).
3The choke control is of lever type. To
remove it, extract its hinge screw, accessible
when the lever is pulled upwards (photo).
4Withdraw the choke cable assembly until
the inner cable can be released from the handcontrol lever and the choke warning lamp lead
unplugged.
5Withdraw the cable assembly through the
engine compartment rear bulkhead.
6Fit the new cable by reversing the removal
operations. Before tightening the inner cable
pinch screw at the carburettor, hold the choke
valve plate open and pull the control lever out
2.0 or 3.0 mm, then tighten the screw. This
will provide just enough free movement to
ensure that when the control is pushed fully in
the choke valve plate will remain fully open
even with engine movement slightly stretching
the cable.
19 Manifolds and exhaust
system
1
1The intake manifold on 903 cc engines is
integral with the cylinder head.
2On the other engines, the intake and
exhaust manifolds are mounted on the same
side of the cylinder head.
3A hot air collector plate is fitted over the
exhaust manifold from where the air cleaner
draws air when in the winter setting.
4When fitting a manifold, thoroughly clean
the cylinder head and manifold mating
surfaces, use a new gasket and tighten nuts
to the specified torque (photos).
5The exhaust system on 903 cc models is of
single downpipe, single silencer two section
type.
3•12 Fuel system
19.4C Fitting intake manifold complete
with carburettor19.4B Fitting exhaust manifold
19.4A Manifold gasket18.3 Extracting choke control lever screw
18.2 Choke cable at carburettor17.5 Accelerator pedal17.4 Throttle cable sleeve and bracket
Page 74 of 303

outwards, they rotate the cam relative to the
distributor shaft, and so advance the spark.
The weights are held in position by two
springs and it is the tension of the springs
which is largely responsible for correct spark
advancement.
The vacuum advance is controlled by a
diaphragm capsule connected to the
carburettor venturi. The vacuum pressure
varies according to the throttle valve plate
opening and so adjusts the ignition advance
in accordance with the engine requirements.
Digiplex ignition system
This electronic system eliminates the
mechanical contact breaker and centrifugal
advance mechanism of conventional
distributors and uses an electronic control
unit to provide advance values according to
engine speed and load. No provision is made
for adjustment of the ignition timing.
Information relayed to the control unit is
provided by two magnetic sensors which
monitor engine speed and TDC directly from
the engine crankshaft.
A vacuum sensor in the control unit
converts intake manifold vacuum into an
electric signal.
The control unit selects the optimum
advance angle required and a closed
magnetic circuit resin coil guarantees a spark
owing to the low primary winding resistance.
Five hundred and twelve advance values
are stored in the control unit memory to suit
any combination of engine operating
conditions.
No maintenance is required to the
distributor used on this system.
Distributor drive
The mechanical breaker type distributor on
903 cc engines and the Digiplex type
distributor on 903 cc ES engines are mounted
on the cylinder head and driven from a gear
on the camshaft through a shaft which also
drives the oil pump.
The distributor on 1116 cc and 1301 cc
engines is mounted on the crankcase and is
driven from a gear on the auxiliary shaft as is
also the oil pump.
2 Mechanical contact breaker
- points servicing
3
1At the intervals specified in “Routine
Maintenance”, prise down the clips on the
distributor cap and place the cap with high
tension leads to one side.
2Pull off the rotor.
3Remove the spark shield. Mechanical wear
of the contact breaker reduces the gap.
Electrical wear builds up a “pip” of burned
metal on one of the contacts. This
|prevents the gap being measured for
re-adjustment, and also spoils the electric
circuit.
Ducellier type distributor
4To remove the contact breaker movable
arm, extract the clip and take off the washer
from the top of the pivot post.
5Extract the screw and remove the fixed
contact arm.
6Clean the points by rubbing the surfaces on
a fine abrasive such as an oil stone. The point
surface should be shaped to a gentle convex
curve. All the “pip” burned onto one contact
must be removed. It is not necessary to go on
until all traces of the crater have been
removed from the other. There is enough
metal on the contacts to allow this to be done
once. At alternate services, fit new points.
Wash debris off cleaned points and
preservatives off new ones.
7Now the distributor should be lubricated.
This lubrication is important for the correct
mechanical function of the distributor, but
excess lubrication will ruin the electrical
circuits, and give difficult starting.
8Whilst the contact breaker is off, squirt
some engine oil into the bottom part of the
distributor, onto the centrifugal advance
mechanism below the plate.
9Wet with oil the felt pad on the top of the
distributor spindle, normally covered by the
rotor arm.
10Put just a drip of oil on the pivot for the
moving contact.11Smear a little general purpose grease
onto the cam, and the heel of the moving
contact breaker.
12Refit the contact points and then set the
gap in the following way.
13Turn the crankshaft by applying a spanner
to the pulley nut or by jacking up a front
wheel, engaging top gear and turning the
roadwheel in the forward direction of
travel. Keep turning until the plastic
heel of the movable contact arm is on the
high point of a cam lobe on the distributor
shaft.
14Set the points gap by moving the fixed
contact arm until the specified feeler blades
are a sliding fit. Tighten the fixed contact arm
screw.
15Check the contact end of the rotor arm.
Remove any slightly burnt deposits using fine
abrasive paper. Severe erosion will
necessitate renewal of the rotor.
16Wipe out the distributor cap and check for
cracks or eroded contacts (photo). Renew if
evident or if the carbon brush is worn.
17Refit the spark shield, rotor and distributor
cap.
18Setting the contact breaker gap with a
feeler blade must be regarded as a means of
ensuring that the engine will start. For
optimum engine performance, the dwell angle
must be checked and adjusted as described
in Section 3.
Marelli type distributor
19Open the points with a finger nail and
inspect their condition. If they are badly
eroded or burned, then they must be
renewed. The contact points can only be
renewed complete with carrier plate as an
assembly.
20Release the low tension leads from the
terminals on the distributor body (photo).
21Extract the screws which hold the vacuum
advance capsule to the distributor body. Tilt
the capsule and release its link rod from the
contact breaker carrier plate (photo).
22Prise out the E-clip from the breaker
carrier and then withdraw the contact
assembly from the top of the distributor shaft.
Ignition system 4•3
2.21 Extracting vacuum diaphragm unit
screw2.20 Marelli distributor2.16 Interior of distributor cap showing
carbon brush
4