1983 FIAT UNO ESP

from the suspension struts and then remove
the bolts which secure the hub carriers to the
U-clamps at the base of the suspension
struts.
23Pull the tops of the hub carriers down and
then outwards and push the driveshafts from
them.
24Unbolt the driveshaft inboard boot
retainers and then remove the driveshafts
from the transmission.
25Support the engine on a hoist or use a
trolley jack under the engine/transmission.
Remove the bottom mounting and then the
upper left and right-hand ones.
26Lower the power unit to the floor by
pushing it to the left-hand side to clear the
right-hand mounting bracket and then swivel
the gearbox towards the rear of the car.
Withdraw the engine/transmission from under
the car.
27External dirt and grease should now be
removed using paraffin and a stiff brush or a
water-soluble solvent.
28Unbolt and remove the engine mounting
brackets and the starter motor.
29Unbolt and remove the cover plate with
the gearchange ball stud strut from the lower
front face of the flywheel housing.
30With the engine resting squarely on its
sump pan, unscrew the flywheel housing
connecting bolts, noting the location of any
lifting lugs and hose and wiring clips.
31Support the weight of the transmission
and withdraw it in a straight line from the
engine.
36 Engine- dismantling (general)
Refer to Section 14, Part 2.
37 Engine ancillary components
- removal
Refer to Section 15, Part 2 and also remove
the intake manifold.
38 Engine-
complete dismantling
3
1Have the engine resting squarely and
supported securely on the work surface.
2Unbolt and remove the timing belt cover.
3Grip the now exposed timing belt with the
hands and loosen the camshaft sprocket.
4Release the timing belt tensioner pulley
centre bolt, then slip the belt from the pulley
and sprockets to remove it. Note which way
round the belt is fitted, usually so that the
lettering on the belt can be read from the
crankshaft pulley end of the engine.
5Remove the camshaft sprocket.6Unbolt and remove the camshaft timing belt
cover backing plate.
7Unbolt and remove the camshaft carrier
cover.
8Unbolt the camshaft carrier and lift it off
very slowly, at the same time pushing the cam
followers and their shims down with the
fingers securely onto their respective valve
springs. It is easy to remove the camshaft
carrier too quickly with some of the cam
followers stuck in it and as the carrier is lifted
away, the cam followers will fall out. If this
happens, the valve clearances will be upset as
the cam followers and shims cannot be
returned, with any certainty, to their original
positions. Keep the cam followers and shims
in their originally fitted order.
9Unscrew and remove the cylinder head
bolts and nuts, grip the manifold, rock the
head and remove the complete cylinder
head/manifold/carburettor assembly. Remove
and discard the cylinder head gasket.
10Unbolt the coolant pump from the side of
the cylinder block and remove it complete
with coolant distribution pipe. Remove the
crankcase breather.
11Remove the distributor/oil pump
driveshaft. This is simply carried out by
inserting a finger into the hole vacated by the
distributor and wedging it in the hole in the
end of the driveshaft. Lift the shaft out of
mesh with the auxiliary shaft. Where the
distributor is driven by the camshaft, a cover
plate retains the oil pump driveshaft in
position.
12Unbolt and remove the sprocket from the
end of the auxiliary shaft. The sprocket is held
to the shaft with a Woodruff key.
13Unbolt the auxiliary shaft retainer and
withdraw the shaft from the crankcase.
14Unscrew and remove the crankshaft
pulley nut. This is very tight and the flywheel
starter ring gear will have to be jammed with a
cold chisel or a suitably bent piece of steel to
prevent the crankshaft rotating.
15Withdraw the crankshaft sprocket, which
is located by the Woodruff key.
16Unbolt the front engine mounting bracket
from the cylinder block, together with the
timing belt cover screw anchor bush. Unbolt
and remove the timing belt tensioner pulley.
17Unscrew the flywheel securing bolts. Thestarter ring gear will again have to be jammed
to prevent the crankshaft rotating as the bolts
are unscrewed. Mark the flywheel position in
relation to the crankshaft mounting flange,
then remove it.
18Unbolt the front and rear crankshaft oil
seal retainer bolts from the crankcase and the
sump. Remove the oil seal retainers.
19Turn the engine on its side, extract the
remaining sump bolts and remove the sump.
If it is stuck, try tapping it gently with a
soft-faced hammer. If this fails, cut all round
the sump-to-gasket flange with a sharp knife.
Do not try prising with a large screwdriver; this
will only distort the sump mating flange.
20With the sump removed, unbolt and
remove the oil pump.
21Grip the oil pick-up pipe and twist or rock
it from its hole in the crankcase. It is an
interference fit in the hole.
22Remove the piston/connecting rods as
described in Section 32.
23Before unbolting the main bearing caps,
note that they are marked with one, two, three
or four notches. No. 5 main bearing cap is
unmarked. Note that the notches are nearer
the auxiliary shaft side.
24Unbolt and remove the main bearing
caps. If the bearing shells are to be used
again, tape them to their respective caps. The
bearing shell at the centre position is plain,
the others have a lubricating groove.
25Carefully, lift the crankshaft from the
crankcase, noting the thrust washers at No. 5
main bearing. These control the crankshaft
endfloat.
39 Cylinder head- dismantling
and decarbonising
4
1The operations are similar to those
described for the ohv engine in Section 17 in
respect of decarbonising and valve grinding.
2To remove a valve, use a valve spring
compressor to compress the first valve and
then extract the split collets (photo).
3Release the valve spring compressor.
4Withdraw the valve spring cap and the
double valve springs (photos).
5Remove the valve (photo).
1•28 1116 cc and 1301 cc engine
39.4A Valve spring cap39.2 Valve spring compressor and split
collets

Fault finding - all engines
Note: When investigating starting and uneven running faults, do not be tempted into snap diagnosis. Start from the beginning of the check
procedure and follow it through. It will take less time in the long run. Poor performance from an engine in terms of power and economy is not
normally diagnosed quickly. In any event, the ignition and fuel systems must be checked first before assuming any further investigation needs to
be made.
All engines 1•35
1
Engine fails to turn when starter operated
m mBattery discharged
m mBattery terminals loose or corroded
m mBattery earth to body defective
m mEngine/transmission earth strap broken or loose
m mDisconnected or broken wire in starter circuit
m mIgnition/starter switch defective
m mStarter motor or solenoid defective (see Chapter 9)
m mMajor mechanical failure (seizure) or long disuse (piston rings rusted
to bores)
Engine turns and fails to start
m mBattery discharged
m mBattery terminals loose or corroded
m mBattery or engine earth strap loose
m mStarter motor connections loose
m mOil in engine/transmission too thick
m mStarter motor defective
m mVapour lock in fuel line (in hot conditions or at high altitude)
m mBlocked float chamber needle valve
m mFuel pump filter blocked
m mChoked or blocked carburettor jets
m mFaulty fuel pump
m mFuel tank empty
m mOther fuel system fault (see Chapter 3)
m mShorted or disconnected low tension leads
m mDirty, incorrectly set, or pitted contact breaker points
m mContact breaker point spring earthed or broken
m mFaulty condenser
m mDefective ignition switch
m mFaulty coil
m mDamp or dirty HT leads, distributor cap or plug bodies
m mBroken, loose or disconnected LT leads
m mIgnition leads connected wrong way round
m mOther ignition fault (see Chapter 4)
m mValve timing incorrect (after rebuild)
Engine fires but will not run
m
mInsufficient choke (cold engine)
m mFuel starvation or tank empty
m mIgnition fault (see Chapter 4)
m mOther fuel system fault (see Chapter 3)
Engine stalls and will not restart
m
mToo much choke allowing too rich a mixture to wet plugs
m mFloat damaged or leaking or needle not seating
m mFloat lever incorrectly adjusted
m mIgnition failure - sudden
m mIgnition failure - misfiring precedes total stoppage
m mIgnition failure - in severe rain or after traversing water splash
m mNo petrol in petrol tank
m mPetrol tank breather choked
m mSudden obstruction in carburettor
m mWater in fuel system
Engine slow to warm up
m
mChoke linkage maladjusted
m mAir cleaner temperature control unit defective
m mThermostat stuck open (see Chapter 2)
m mOther fuel system fault (see Chapter 3)
Difficult starting when cold
m
mInsufficient choke
m mFouled or incorrectly gapped spark plugs
m mDamp or dirty HT leads, distributor cap or spark plug bodies
m mDirty or maladjusted contact breaker points
m mOther ignition fault or timing maladjustment (see Chapter 4)
m mFuel system or emission control fault (see Chapter 3)
m mPoor compression (may be due to incorrect valve clearances, burnt
or sticking valves, blown head gasket, worn or damaged pistons,
rings or bores)
m mIncorrect valve timing (after rebuild)
Difficult starting when hot
m
mIncorrect use of manual choke
m mFuel line vapour lock (especially in hot weather or at high altitudes)
m mIncorrect ignition timing
m mOther fuel system or emission control fault (see Chapter 3)
m mPoor compression (see above)
Engine lacks power
m
mIgnition timing incorrect
m mContact breaker points incorrectly gapped
m mIncorrectly set spark plugs
m mDirty contact breaker points
m mDistributor automatic advance and retard mechanisms not
functioning correctly
m mOther ignition system fault (see Chapter 4)
m mAir cleaner choked
m mCarburation too rich or too weak
m mFuel filter blocked
m mAir filter blocked
m mFaulty fuel pump giving top and fuel starvation
m mOther fuel system fault (see Chapter 3)
m mPoor compression
m mValve clearances incorrect
m mCarbon build-up in cylinder head
m mSticking or leaking valves
m mWeak or broken valve springs
m mWorn valve guides or stems
m mWorn pistons and piston rings
m mBurnt out valves
m mBlown cylinder head gasket (accompanied by increase in noise)
m mWorn pistons and piston rings
m mWorn or scored cylinder bore
m mBrakes binding
Engine misfires throughout speed range
m
mDefective or fouled spark plug
m mLoose, cracked or defective HT lead
m mMaladjusted, sticking or burnt valves
m mIgnition timing incorrect
m mBlown head gasket
m mFuel contaminated
m mOther ignition fault (see Chapter 4)
m mOther fuel system fault (see Chapter 3)
Poor engine braking
m
mHigh idle speed
m mOther fuel system fault (see Chapter 3)
m mLow compression

towards the engine. Slip the belt off the
pulleys. If this is difficult, turn the crankshaft
pulley using a spanner on its retaining nut
while pressing the belt over the edge of the
pulley rim. Use this method to fit the new belt
after first having engaged it with the coolant
pump and alternator pulley grooves.
5Tension the belt as previously described.
6The tension of a new belt should be
checked and adjusted after the first few
hundred miles of running.
9 Coolant pump- removal,
overhaul and refitting
4
Note: The design of the pump differs between
the 903 cc and the other two engines, but the
removal, overhaul and refitting operations are
essentially similar.
1To gain access to the coolant pump, open
the bonnet and remove the air cleaner.
2Slacken the alternator pivot and adjustment
nuts, push the alternator in towards the
engine and slip the drivebelt from the coolant
pump pulley. Unplug and remove the
alternator.3Drain the cooling system as previously
described.
4Disconnect the hoses from the coolant
pump, also the metal coolant transfer pipe
(photo).
5Unscrew and remove the coolant pump
securing bolts, and lift the pump from the
engine. Peel away and discard the old gasket.
6Clean away external dirt.
7The pump is likely to need overhaul for
worn or noisy bearings, or if the gland is
leaking. There is a drain hole between the
gland and the bearings to prevent
contamination of the bearing grease by leaks,
and possible damage to the bearings. Glandleaks are usually worse when the engine is not
running. Once started, a leak is likely to get
worse quickly, so should be dealt with soon.
Worn bearings are likely to be noted first due
to noise. To check them, the pulley should be
rocked firmly, when any free movement can
be felt despite the belt. But if the bearings are
noisy, yet there is not apparently any free
play, then the belt should be removed so the
pump can be rotated by hand to check the
smoothness of the bearings.
8Dismantling and assembly of the pump
requires the use of a press, and it is preferable
to fit a new pump.
9For those having the necessary facilities,
overhaul can be carried out as follows.
10Remove the retaining nuts and separate
the two halves of the pump.
11The pump shaft is an interference fit in the
impeller, bearings, and pulley boss. How the
pump is dismantled depends on whether only
the gland needs renewing or the bearings as
well, and what puller or press is available to
get everything apart.
12Assuming complete dismantling is
required, proceed as follows. Supporting it
close in at the boss, press the shaft out of the
pulley. Pull the impeller off the other end of
the shaft.
13Take out the bearing stop screw.
14From the impeller end, press the shaft
with the bearings out of the cover half of the
housing.
15Press the shaft out of the bearings, take
off the spacer, the circlip, and the shouldered
ring.
16Do not immerse the bearings in cleaning
2•4 Cooling and heating systems
1 Pump body
2 Pump cover
3 Impeller
4 Connector for hose from
outlet to pump
5 Seal
6 Gasket7 Circlip
8 Bearing shoulder washer
9 Inner seal
10 Inner bearing
11 Bearing retainment screw
and lock washer12 Spacer
13 Outer seal
14 Outer bearing
15 Lock washer
16 Pulley
17 Pump shaft
Fig. 2.5 Sectional views of 1116 cc and 1301 cc engine coolant pump (Sec 9)
Fig. 2.4 Sectional view of 903 cc engine coolant pump (Sec 9)
9.4 Coolant distribution tube at rear of
pump
1 Pump cover
2 Bearing spacer
3 Bearing stop screw
4 Cover nuts
5 Lifting bracket
6 Housing
7 Impeller
8 Gland (seal)
9 Circlip
10 Gasket
11 Shouldered ring
12 Grommets
13 Bearing
14 Pulley
15 Shaft

12The air cleaner on the 1301 cc engine is
mounted on the four flange studs of the
carburettors, their nuts being accessible after
the air cleaner lid has been removed and the
filter element extracted.
13Refitting of all types of air cleaner is a
reversal of removal.
3 Fuel pump-
removal and refitting
2
1On 903 cc engines, the fuel pump is
mounted on the side of the timing chain cover
and is driven by a pushrod from an eccentric
on the front of the camshaft.
2On the 1116 cc and 1301 cc engines, the
fuel pump is mounted on the side of the
crankcase and is driven by a pushrod from an
eccentric on the auxiliary shaft.
3The removal of both types of pump is
carried out in a similar way.
4Disconnect the fuel inlet hose from the
pump and plug the hose (photo).
5Disconnect the fuel outlet hose from the
pump.
6Unscrew the pump fixing bolt and remove it
together with spacer, pushrod and gaskets
(photos).
7Refitting is a reversal of removal. Make sure
that a new gasket is located on each side of
the spacer.
8The gasket on the inboard side of thespacer should always be 0.3 mm thick, but
gaskets for the outboard side are available in
thicknesses 0.3, 0.7 and 1.2 mm, as a means
of adjusting the fuel pump pressure. The
standard fuel pressure is 0.176 bar
(2.55 lbf/in
2). If the pressure is too high a
thicker gasket should be used, if too low, fit a
thinner one.
4 Fuel level transmitter-
removal and refitting
1
1The transmitter is accessible after having
removed the small cover panel from the floor
of the car under the rear seat (tipped forward)
with the floor covering peeled back (photo).
2Disconnect the fuel flow and return hoses
and the electrical leads from the transmitter.
3Unscrew the securing ring and lift the
transmitter from the tank.
4Refitting is a reversal of removal. Use a new
rubber sealing ring.
5 Fuel tank-
removal and refitting
1
1It is preferable to remove the fuel tank when
it has only a very small quantity of fuel in it. Ifthis cannot be arranged, syphon out as much
fuel as possible into a suitable container
which can be sealed.
2The tank is mounted just forward of the rear
axle.
3Disconnect the filler hose and the breather
hose from the tank (photo).
4Unscrew the mounting bolts from the
support straps and lower the tank using a jack
with a block of wood as an insulator. Release
the handbrake cable from its support bracket
on the side of the tank (photo).
5Once the tank has been lowered sufficiently
far, disconnect the fuel supply and return
hoses, breather hose and sender unit leads
and remove the tank from the car.
Warning: Never attempt to
solder or weld a fuel tank
yourself; always leave fuel tank
repairs to the experts. Never
syphon fuel into a container in an
inspection pit. Fuel vapour is heavier than
air and can remain in the pit for a
considerable time.
6If the tank contains sediment or water,
clean it out by using several changes of
paraffin and shaking vigorously. In order to
avoid damage to the sender unit, remove this
before commencing operations.
7Finally allow to drain and rinse out with
clean fuel.
8Refit by reversing the removal operations.
9On 1984 and later models, the fuel tank is
of plastic construction.
Fuel system 3•5
3.6B Fuel pump spacer and pushrod3.6A Fuel pump on mounting studs3.4 Fuel pump
5.4 Fuel tank mounting straps5.3 Fuel tank filler and vent hoses4.1 Fuel tank transmitter
3

6On 1116 cc and 1301 cc models, the
exhaust system is of dual downpipe, two
silencer, two section type.
7The exhaust system is flexibly mounted
(photo).
8Do not attempt to separate the sections ofthe exhaust system, while in position in the
car. Unbolt the pipe from the manifold and,
using a screwdriver, prise off the flexible
suspension rings. Provided the car is then
raised on jacks, ramps or placed over
an inspection pit, the complete exhaust system can be withdrawn from under the car.
9If only one section is to be renewed, it is far
easier to separate once the complete system
is out of the car.
10When refitting, grease the pipe sockets
and fit the clamps loosely until the suspension
rings are connected and the downpipe bolted
up (using a new copper gasket). Check the
attitude of the sections with regard to each
other and the adjacent parts of the
underbody. Fully tighten the clamps and
downpipe flange nuts, remembering to bend
up the lockplate tabs on 1116 cc and 1301 cc
models (photo).
11On the larger engined models, it may be
necessary to raise the vehicle at the rear and
support it on axle stands so that the rear sus-
pension hangs down and is fully extended.
This will allow sufficient clearance between
the axle and the body for the exhaust system
to be withdrawn.
Fuel system 3•13
3
19.10 Exhaust pipe socket clamp19.7B Exhaust tailpipe mounting
Fault finding - fuel system
Unsatisfactory engine performance and excessive fuel consumption
are not necessarily the fault of the fuel system or carburettor. In fact they
more commonly occur as a result of ignition and timing faults. Before
acting on the following it is necessary to check the ignition system first.
Even though a fault may lie in the fuel system it will be difficult to trace
unless the ignition is correct. The faults below, therefore, assume that
this has been attended to first (where appropriate).
Smell of petrol when engine is stopped
m mLeaking fuel lines or unions
m mLeaking fuel tank
Smell of petrol when engine is idling
m
mLeaking fuel line unions between pump and carburettor
m mOverflow of fuel from float chamber due to wrong level setting,
ineffective needle valve or punctured float
Excessive fuel consumption for reasons not
covered by leaks or float chamber faults
m mWorn jets
m mOver-rich setting
m mSticking mechanism
m mDirty air cleaner element
Difficult starting when cold
m
mChoke control
m mInsufficient use of manual choke
m mWeak mixture
Difficult starting, uneven running, lack of power,
cutting out
m mOne or more jets blocked or restricted
m mFloat chamber fuel level too low or needle valve sticking
m mFuel pump not delivering sufficient fuel
m mInduction leak
Difficult starting when hot
m
mExcessive use of manual choke
m mAccelerator pedal pumped before starting
m mVapour lock (especially in hot weather or at high altitude)
m mRich mixture
Engine does not respond properly to throttle
m
mFaulty accelerator pump
m mBlocked jet(s)
m mSlack in accelerator cable
Engine idle speed drops when hot
m
mIncorrect air cleaner intake setting
m mOverheated fuel pump
Engine runs on
m
mIdle speed too high

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

this type is used and the engine is in good
condition, the spark plugs should not need
attention between scheduled replacement
intervals. Spark plug cleaning is rarely
necessary and should not be attempted unless
specialised equipment is available as damage
can easily be caused to the firing ends.
2At the specified intervals, the plugs should
be renewed. The condition of the spark plug
will also tell much about the overall condition
of the engine.
3If the insulator nose of the spark plug is
clean and white, with no deposits, this is
indicative of a weak mixture, or too hot a plug.
(A hot plug transfers heat away from the
electrode slowly - a cold plug transfers it away
quickly.)
4If the tip of the insulator nose is covered
with sooty black deposits, then this is
indicative that the mixture is too rich. Should
the plug be black and oily, then it is likely that
the engine is fairly worn, as well as the mixture
being too rich.
5The spark plug gap is of considerable
importance, as, if it is too large or too small
the size of the spark and its efficiency will be
seriously impaired. The spark plug gap should
be set to the gap shown in the Specifications
for the best results.
6To set it, measure the gap with a feeler
gauge, and then bend open, or close, the
outer plug electrode until the correct gap is
achieved. The centre electrode should never
be bent as this may crack the insulation and
cause plug failure, if nothing worse.
7When fitting new plugs, check that the plug
seats in the cylinder head are quite clean.
Refit the leads from the distributor in the
correct firing order, which is 1-3-4-2; No 1cylinder being the one nearest the flywheel
housing (903 cc) or timing belt (1116 or
1301 cc). The distributor cap is marked with
the HT lead numbers to avoid any confusion.
Simply connect the correctly numbered lead
to its respective spark plug terminal (photo).
12 Ignition switch-
removal and refitting
1
1Access to the steering column lock/ignition
switch is obtained after removing the steering
wheel and column shrouds (Chapter 10) and
the column switch unit (Chapter 9).
2In the interest of safety, disconnect the
battery negative lead and the ignition switch
wiring plug (photo).
3Insert the ignition key and turn to the STOP
position (photo).
4Pull the two leads from the switch.
5Turn the ignition key to MAR.
6Using a screwdriver depress the retaining
tabs (1) (Fig. 4.16) and release the ignition
switch.
7Set the switch cam (2) so that the notches
(3) are in alignment.
8Insert the switch into the steering lock and
engage the retaining tabs.
9Turn the ignition key to STOP and connect
the two leads.
10Reconnect the battery and refit the
steering wheel, switch and shrouds.
11Removal and refitting of the steeringcolumn lock is described in Chapter 10.
Note: The ignition key is removable when set
to the STOP position and all electrical circuits
will be off. If the interlock button is pressed,
the key can be turned to the PARK position in
order that the parking lamps can be left on
and the steering lock engaged, but the key
can be withdrawn.
4•8 Ignition system
Fig. 4.16 Typical ignition switch (Sec 12)
1 Retaining tabs 3 Alignment notches
2 Switch cam 4 Locating projection12.3 Ignition key positions
1 AVV (Start) 3 Stop (Lock)
2 Park (Parking lights on) 4 MAR (Ignition)12.2 Ignition switch and lock
11.7 Distributor cap HT lead markingsFig. 4.15 Spark plug connections on
1116 cc and 1301 cc engines (Sec 11)
Fig. 4.14 Spark plug connections on
903 cc engine (Sec 11)
It’s often difficult to insert spark plugs
into their holes without cross-threading
them. To avoid this possibility, fit a
short piece of rubber hose over the end
of the spark plug. The flexible hose
acts as a universal joint, to help align
the plug with the plug hole. Should the
plug begin to cross-thread, the hose
will slip on the spark plug, preventing
thread damage.

into its cylinder to accommodate them. This
will cause the fluid level to rise in the reservoir.
Anticipate this by syphoning some out
beforehand, but take care not to let it drip
onto the paintwork - it acts as an effective
paint stripperl
8Refit the anti-rattle springs, the pads
(friction lining-to-disc), the cylinder body, the
locking blocks and their retaining clips
(photos).
9Refit the roadwheel and apply the footbrake
hard, several times, to bring the pads into
contact with the brake disc.
10Renew the pads on the opposite brake.
The pads should always be renewed in axle
sets.
11Top up the fluid reservoir.
4 Rear brake shoes-
inspection and renewal
2
1Jack up the rear of the car and remove the
roadwheels.
2Fully release the handbrake.
3Unscrew and remove the drum securing
bolts. One of these is a long locating spigot
for the roadwheel.
4Pull off the drum. lf it is tight, clean off the
rust at its joint with the hub flange, and apply
a little penetrating fluid. Two bolts may be
screwed into the drum securing bolt holes if
necessary and the drum thus eased off the
hub. The securing bolt holes are tapped for
this purpose.
5Brush away all the dust and dirt from the
shoes and operating mechanism, taking care
not to inhale it.
6The friction linings fitted as original
equipment are of the bonded type and the
rivet heads normally used as a guide to wear
are not, of course, fitted. However, if the
thickness of the friction linings is down to
1.5 mm (0.06 in) or less, the shoes must be
renewed. Always purchase new or factory
relined brake shoes.
7Before removing the brake shoes, note the
way in which the shoes are positioned, with
respect to leading and trailing ends (the end
of the shoe not covered by lining material).Note also into which holes in the shoe web
the return springs are connected. Sketch the
shoes or mark the holes on the new shoes
with quick drying paint if you are doubtful
about remembering (photo).
8Undo the steady springs by depressing and
rotating their caps a quarter turn to disengage
the slot from the pin. On later models a
U-shaped steady spring is used. Depress and
slide it out.
9Rotate the hub until the cut-outs in its rear
flange face are in alignment with the shoe
self-adjusters.
10Pivot the trailing shoe on the self-adjuster
post and disengage the ends of the shoe from
the slot in the wheel cylinder tappet and from
the lower anchor block.
11Work the shoe up the self-adjuster pivot
post until the self-adjuster boss enters the
cut-out in the hub flange. The shoe can now
be withdrawn (photo).
12Once off the self-adjuster post, the
pull-off spring tension is eased, as the shoe
can move towards the other, so the springs
can be unhooked.
13Remove the leading shoe in a similar way.
14The new shoes will already be fitted with
new self-adjusters.
15Fit the new shoes to their self-adjuster
posts, making sure that the handbrake shoe
lever is correctly located. Engage the ends of
the shoes.
16Using a wooden or plastic-faced mallet,
tap the shoes inwards against the friction of
their self-adjuster coil springs. This will havethe effect of reducing the overall diameter of
the shoes to facilitate fitting of the shoe return
springs and to allow the brake drum to slide
over them.
17Using pliers, reconnect the upper (longer)
and lower shoe return springs.
18Hold the steady pins in position from the
rear of the backplate. Fit the small coil springs
and the retaining cap, again using pliers to
grip the cap and to depress and turn it to
engage the pin. On later models fit the
U-shaped springs.
19Before refitting the drum, clean it out and
examine it for grooves or scoring (refer to
Section 8).
20Fit the drum and the roadwheel.
21Apply the brakes two or three times to
position the shoes close to the drum.
22Renew the shoes on the opposite brake in
a similar way.
23The handbrake should be automatically
adjusted by the action of the shoe adjuster. If
the handbrake control lever has excessive
travel, refer to Section 16 for separate
adjusting instructions.
5 Caliper- removal,
overhaul and refitting
4
Note: Purchase a repair kit in advance of
overhaul.
1Jack up the front roadwheel and remove it.
2Brush away all dirt from the caliper
Braking system 8•3
4.11 Rear hub showing cut-outs on rear
face for shoe self-adjuster bosses4.7 Rear brake assembly3.8B Cylinder body located on caliper
bracket
Fig. 8.2 Exploded view of caliper (Sec 5)
8