weight FIAT UNO 1983 Service User Guide

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

7 Carburettor idle speed and
mixture- adjustment
4
1All carburettors have their mixture
adjustment set in production. The screw is
fitted with a tamperproof cap.
2Under normal circumstances, only the idle
speed screw need be adjusted to set the
engine idle speed to the specified level.
3Before attempting to adjust the idle speed
or mixture, it is important to have the ignition
and valve clearances correctly set and the
engine at normal operating temperature with
the air cleaner fitted.
4Where the mixture must be adjusted, prise
out the tamperproof plug and turn the mixture
screw in to weaken or out to enrich the
mixture until the engine runs smoothly without
any tendency to “hunt”.
5Ideally an exhaust gas analyser should be
used to make sure that the CO level is within
the specified range.
6Once the mixture has been correctly set,
re-adjust the idle speed screw.
8 Carburettor-
removal and refitting
2
1Remove the air cleaner.
2Disconnect the flow and return fuel hoses
from the carburettor and plug them.3Disconnect the coolant hoses from the
carburettor throttle valve plate block.
Provided the cooling system is cold and not
under pressure there should be almost no loss
of coolant. Tie the hoses up as high as
possible with a piece of wire.
4Disconnect the vacuum and vent hoses
from the carburettor.
5Disconnect the throttle and choke controls
from the carburettor.
6Unscrew the mounting flange nuts and lift
the carburettor from the intake manifold
(photo).
7Refitting is a reversal of removal. Use a new
flange gasket and make sure that the fuel
return hose is routed above the air cleaner
intake.
9 Carburettor
(Weber 32 ICEV 50/250/1)-
servicing and adjustment
4
1The carburettor top cover with float may be
removed without the need to withdraw the
carburettor from the manifold. The other
adjustments described will require removal of
the carburettor.
2Unscrew the filter plug from the top cover,
clean the filter screen and refit it.
3Extract the top cover fixing screws, lift the
cover and tilt it to unhook it from the
diaphragm capsule link rod.
4Access to the fuel inlet needle valve isobtained by carefully tapping out the float arm
pivot pin. Take care, the pivot pin pillars are
very brittle.
5Check that the needle valve body is tight
otherwise fuel can bypass the needle valve
and cause flooding.
Float adjustment
6Reassemble and check the float setting. Do
this by holding the top cover vertically so that
the float hangs down under its own weight.
Measure dimension (A) (Fig. 3.10) which
should be between 1 0.50 and 11.10 mm
(0.41 to 0.44 in) with the gasket in position. If
necessary, bend the float arm tab to adjust.
7Now check the float travel which should be
45.0 mm (1.77 in). If adjustment is required,
bend the end of the float arm.
Accelerator pump stroke
8Using a twist drill as a gauge, open the
throttle valve plate through 3.5 mm (0.138 in).
9Turn the nut on the accelerator pump rod
until it just makes contact with the pump
control lever.
Fast idle adjustment
10With the choke valve plate fully closed by
means of the control lever, the throttle valve
Fuel system 3•7
Fig. 3.9 Fuel return hose correctly located
(Sec 8)
8.6 Carburettor mounting flange nut8.2 Fuel hose at carburettor
Fig. 3.10 Float setting diagram (Weber 32 ICEV 50/250) (Sec 9)
A = 10.5 to 11.0 mm (0.41 to 0.44 in) B = 45.0 mm (1.77 in)Fig. 3.11 Accelerator pump setting diagram
(Weber 32 ICEV 50/250) (Sec 9)
X = 3.5 mm (0.138 in)
3

plate should be open (dimension A) (Fig. 3.1 2)
between 0.75 and 0.80 mm (0.030 and
0.032 in). Adjust if necessary by means of the
screw and locknut.Anti-flooding device
11This consists of a diaphragm capsule and
link rod.
12The condition of the diaphragm can be
checked by applying a vacuum source to the
hole in the throttle valve plate block. The
vacuum pressure will drop if there is a leak.
13Actuate the choke valve plate lever fully
and depress the control lever of the
anti-flooding device to simulate operating
vacuum.
14There should be a gap (Y) (Fig. 3.15)
between the edge of the choke valve plate
and the wall of the carburettor throat of
between 3.75 and 4.25 mm (0.148 and
0.167 in). Any adjustment that may be needed
should be carried out by bending the link rod.
10 Carburettor
(Solex C32 DISA 11)-
servicing and adjustment
4
1The carburettor top cover with float may be
removed without the need to withdraw the
carburettor from the manifold. The other
adjustments described will require removal of
the carburettor.2Extract the top cover fixing screws,
disconnect the small externally mounted
tension spring and take off the top cover.
3Access to the fuel inlet needle valve is
obtained by carefully tapping out the float arm
pivot pin. Take care, the pivot pin pillars are
very brittle.
4Check that the needle valve body is tight
otherwise fuel can bypass the needle valve
and cause flooding.
Float adjustment
5Reassemble and check the float setting. Do
this by inverting the top cover so that the
weight of the float fully depresses the ball of
the needle valve. The distance (A) (Fig. 3.16)
between the float and the surface of the top
cover flange gasket should be between 2.0
and 3.0 mm (0.079 and 0.118 in). If
adjustment is required, alter the thickness of
the washer under the needle valve.
Accelerator pump
6Fill the carburettor float chamber and then
operate the throttle valve plate lever several
times to prime the pump.
7Position a test tube under the accelerator
3•8 Fuel system
Fig. 3.16 Float setting diagram
(Solex C32 DISA 11) (Sec 10)
A = 2.0 to 3.0 mm (0.079 to 0.118 in)
Fig. 3.17 Adjusting accelerator pump rod
(Solex C32 DISA 11) (Sec 10)
Fig. 3.15 Choke valve gap opening
(Weber 32 ICEV 50/250) (Sec 9)
Y = 3.75 to 4.25 mm (0.148 to 0.167 in)
Fig. 3.14 Anti-flooding device vacuum
intake (Weber 342 ICEV 50/250) (Sec 9)
1 Vacuum intake hole
Fig. 3.12 Fast idle adjustment diagram (Weber 32 ICEV 50/250)
(Sec 9)
A = 0.75 to 0.80 mm (0.030 to 0.032 in)Fig. 3.13 Anti-flooding device (Weber 32 ICEV 50/250)
(Sec 9)
Y = 3.75 to 4.25 mm (0.148 to 0.167 in)

control unit is functioning, if the tachometer
does not register, renew the ignition control
unit.
16If a replacement carburettor is to be fitted,
only fit the Solex assembly including the
control module, even if a Weber was originally
fitted.
12 Carburettor
(Weber 32 ICEV 51/250)-
servicing and adjustment
4
1This carburettor, fitted to 1116 cc engines,
is very similar to the unit described in Sec-
tion 9.
2The fast idle adjustment procedure is
identical, but note that dimension (A) (Fig.
3.12) should be between 0.85 and 0.90 mm
(0.033 and 0.035 in).
3The choke valve plate gap (Y) (Fig. 3.13)
should be between 5.5 and 6.5 mm (0.22 and
0.26 in) and if adjustment is required, bend
the stop on the control lever.
13 Carburettor
(Solex C32 DISA 12)-
servicing and adjustment
4
1This carburettor is an alternative to the
Weber fitted to 1116 cc engines.
2The adjustments described in Section 9
apply.
14 Carburettor
(Weber 30/32 DMTR 90/250)
- servicing and adjustment
4
1The carburettor top cover with float may be
removed without the need to withdraw the
carburettor from the manifold. The other
adjustments described in this Section will
require removal of the carburettor.
2Extract the top cover fixing screws and lift
away the top cover with float. Access to the
fuel inlet needle valve is as described in
Section 9 paragraphs 4 and 5.
Float adjustment
3Hold the cover vertically so that the floats
hang down under their own weight. Measure
the distance between the float and the surface
of the gasket on the top cover. This should be
between 6.75 and 7.25 mm (0.27 and 0.29 in).
4Bend the float arm if necessary to adjust
the setting.
Primary valve plate opening
5With the throttle valve plate control lever in
contact with the stop, the primary valve plate
should be open (dimension X Fig. 3.22)
between 6.45 and 6.95 mm (0.25 and 0.27 in).
If adjustment is required, carefully bend the
lever stop.
Primary and secondary valve
plate openings
6With the throttle control lever fully actuated
the valve plate gaps (X and Y Fig. 3.24) should
be:
X = 13.5 to 14.5 mm (0.53 to 0.57 in)
Y = 14.5 to 15.5 mm (0.57 to 0.61 in)
Fast idle
7Close the choke valve plate fully and check
the gap (A) (Fig. 3.25) between the edge of the
throttle valve plate and the carburettor throat.
The gap should be between 0.90 and
0.95 mm (0.035 and 0.037 in), a twist drill is
useful for measuring this.
8If adjustment is required, carry this out
using the screw and locknut.
Anti-flooding device
(mechanically-operated)
9With the choke control pulled fully out, it
should be possible to open the choke valve
plate to give a gap (X) of between 7.0 and
7.5 mm (0.28 and 0.30 in). If adjustment is
required, carefully bend the stop on the
control lever (Fig. 3.26).
3•10 Fuel system
Fig. 3.26 Anti-flooding device (mechanical)
adjustment diagram
(Weber 30/32 DMTR 90/250) (Sec 14)
X = 7.0 to 7.5 mm (0.28 to 0.30 in)Fig. 3.25 Fast idle adjustment diagram
(Weber 30/32 DMTR 90/250) (Sec 14)
A = 0.90 to 0.95 mm (0.035 to 0.037 in)
Fig. 3.24 Throttle valve plate openings
(Weber 30/32 DMTR 90/250) (Sec 14)
X (primary) = 13.5 to 14.5 mm (0.53 to 0.57 in)
Y (secondary) = 14.5 to 15.5 mm (0.57 to 0.61 in)Fig. 3.23 Bending throttle lever stop
(Weber 30/32 DMTR 90/250) (Sec 14)Fig. 3.22 Primary valve plate opening
(Weber 30/32 DMTR 90/250) (Sec 14)
X = 6.45 to 6.95 mm (0.25 to 0.27 in)

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)

Spark plugs
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion RN9YCC or RN9YC
Electrode gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.8 mm (0.031 in)
HT leads
903 cc (45) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion LS-07
1116, 1299 and 1301 cc (55, 60 and 70) . . . . . . . . . . . . . . . . . . . . . . . . Champion LS-05
Torque wrench settingNm lbf ft
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
4•2 Ignition system
1 General description
On all models except the 903 ES engine
version, a mechanical contact breaker type
distributor is fitted.
On 45 Super ES models which have the
903 ES engine, an electronic (Digiplex) ignition
system is used which incorporates a
breakerless distributor.
Mechanical contact breaker
system
For the engine to run correctly, it is
necessary for an electrical spark to ignite the
fuel/air mixture in the combustion chamber at
exactly the right moment in relation to engine
speed and load. The ignition system is based
on feeding low tension voltage from the
battery to the coil where it is converted to high
tension voltage. The high tension voltage is
powerful enough to jump the spark plug gap
in the cylinders under high compression
pressures, providing that the system is in
good condition and that all adjustments are
correct.
The ignition system is divided into two
circuits, the low tension (LT) circuit and the
high tension (HT) circuit.
The low tension (sometimes known as the
primary) circuit consists of the battery, the
lead to the ignition switch, the lead from the
ignition switch to the low tension or primary
coil windings, and the lead from the low
tension coil windings to the contact breaker
points and condenser in the distributor.
The high tension circuit consists of the high
tension or secondary coil windings, the heavy
ignition lead from the centre of the coil to the
centre of the distributor cap, the rotor arm,
and the spark plug leads and spark plugs.
The system functions in the following
manner: High tension voltage is generated in
the coil by the interruption of the low tension
circuit. The interruption is effected by the
opening of the contact breaker points in this
low tension circuit. High tension voltage is fed
from the centre of the coil via the carbon
brush in the centre of the distributor cap to
the rotor arm of the distributor.
The rotor arm revolves at half engine speed
inside the distributor cap, and each time it
comes in line with one of the four metal
segments in the cap, which are connected to
the spark plug leads, the opening of thecontact breaker points causes the high
tension voltage to build up, jump the gap from
the rotor arm to the appropriate metal
segment, and so via the spark plug lead to the
spark plug, where it finally jumps the spark
plug gap before going to earth.
The ignition timing is advanced and
retarded automatically, to ensure the sparkoccurs at just the right instant for the
particular load at the prevailing engine speed.
The ignition advance is controlled
mechanically, and by vacuum. The
mechanical governor mechanism consists of
two weights, which move out from the
distributor shaft as the engine speed rises,
due to centrifugal force. As they move
Fig. 4.1 Typical ignition circuit (mechanical contact breaker distributor) (Sec 1)
1 Control unit
2 Multi-plug
3 Ignition coil
4 Distributor cap5 Crankshaft pulley
6 Flywheel
7 Battery
8 Rev counter9 Spark plugs
10 Wiring connector
S1 Engine speed sensor
S2 TDC sensor
Fig. 4.2 Digiplex electronic ignition system (Sec 1)

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

5 Condenser (capacitor)-
removal, testing and refitting
1
The purpose of the condenser (sometimes
known as the capacitor) is to ensure that when
the contact breaker points open there is no
sparking across them which would weaken
the spark and cause rapid deterioration of the
points.
The condenser is fitted in parallel with the
contact breaker points. If it develops a short
circuit it will cause ignition failure as the points
will be prevented from interrupting the low
tension circuit.
1If the engine becomes very difficult to start
(or begins to misfire whilst running) and the
breaker points show signs of excessive
burning, suspect the condenser has failed
with open circuit. A test can be made by
separating the points by hand with the ignition
switched on. If this is accompanied by a
bright spark at the contact points, it is
indicative that the condenser has failed.
2Without special test equipment, the only
sure way to diagnose condenser trouble is to
replace a suspected unit with a new one and
note if there is any improvement.
3To remove the condenser from the
distributor, take out the screw which secures
it to the distributor body and disconnect its
leads from the terminals.
4When fitting the condenser, it is vital to
ensure that the fixing screw is secure. The
lead must be secure on the terminal with no
chance of short circuiting.
6 Distributor-
removal and refitting
3
1Remove the spark plug from No. 4 cylinder
and then turn the crankshaft either by
applying a spanner to the pulley nut or by
jacking up a front wheel, engaging top gear
and turning the wheel in the forward direction
of travel.
2Place a finger over the plug hole and feel
the compression being generated as the
piston rises up the cylinder bore.
3Alternatively, if the rocker cover is off,
check that the valves on No. 1 cylinder are
closed.
4Continue turning the crankshaft until the
flywheel and flywheel housing (BTDC) ignition
timing marks are in alignment. Number 4
piston is now in firing position.
5Remove the distributor cap and place it to
one side complete with high tension leads.
6Disconnect the distributor vacuum hose
and low tension lead (photo).
7Mark the distributor pedestal mounting
plinth in relation to the crankcase. Also mark
the contact end of the rotor in relation to the
rim of the distributor body.8Unbolt the clamp plate and withdraw the
distributor.
9Refit by having No. 4 piston at its firing
position and the distributor rotor and pedestal
marks aligned, then push the distributor into
position, mating it to the splined driveshaft.
10If a new distributor is being fitted then of
course alignment marks will not be available
to facilitate installation in which case, hold the
unit over its mounting hole and observe the
following.
903 cc engine: Distributor cap high tension
lead sockets pointing towards alternator and
at 90º to centre line of rocker cover. Contact
end of rotor arm pointing towards No. 4
contact in distributor cap (when fitted).
1116 cc and 1301 cc engine: Distributor
vacuum unit pointing downwards at 135º to
rear edge of timing belt cover. Contact end of
rotor arm pointing towards No. 4 contact in
distributor cap (when fitted).
11Tighten the distributor clamp bolt,
reconnect the vacuum hose and the low
tension leads. Refit the distributor cap. Screw
in the spark plug.
12Check the ignition timing as described in
Section 4.
7 Distributor (mechanical
breaker type)- overhaul
3
Ducellier
1The cap must have no flaws or cracks and
the HT terminal contacts should not be
severely corroded. The centre spring-loaded
carbon contact is renewable. If in any doubt
about the cap, buy a new one.
2The rotor deteriorates minimally, but with
age the metal conductor tip may corrode. It
should not be cracked or chipped and the
metal conductor must not be loose. If in
doubt, renew it. Always fit a new rotor if fitting
a new cap.
3With the distributor removed as described
in the preceding Section, take off the rotor
and contact breaker.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.
6Carefully record the setting of the advance
toothed segment and then remove the spring
clip and vacuum capsule fixing screws and
withdraw the capsule with link rod.
7Pick out the lubrication pad from the recess
in the top of the distributor shaft. Unscrew the
screw now exposed.
8Mark the relationship of the cam to the
counterweight pins and then remove the cam
assembly.
9There is no way to test the bob weight
springs other than by checking the
performance of the distributor on special test
equipment, so if in doubt, fit new springs
anyway. If the springs are loose where they
loop over the posts, it is more than possible
that the post grooves are worn. In this case,
the various parts which include the shaft will
need renewal. Wear to this extent would mean
that a new distributor is probably the best
solution in the long run. Be sure to make note
of the engine number and any serial number
on the distributor when ordering.
10If the mainshaft is slack in its bushes or
the cam on the spindle, allowing sideways
play, it means that the contact points gap
setting can only be a compromise; the cam
position relative to the cam follower on the
moving point arm is not constant. It is not
practical to re-bush the distributor body
unless you have a friend who can bore and
bush it for you. The shaft can be removed by
driving out the roll pin from the retaining collar
at the bottom. (The collar also acts as an oil
slinger to prevent excess engine oil creeping
up the shaft.)
Marelli
11With the distributor removed from the
engine, take off the spark shield and rotor.
12Remove the contact breaker and carrier
as described in Section 2.
13Refer to paragraphs 9 and 10 for details of
counterweight springs and shaft bushes
(photo).
Ignition system 4•5
6.6 Distributor LT connection4.5 Distributor clamp plate nut
4

Reassembly
14This is a reversal of dismantling. On
Ducellier distributors, make sure that the
advance toothed segment is returned to its
original setting otherwise the advance curves
for your particular engine will be upset.
8 Ignition coil (mechanical
breaker ignition)
1Coils normally last the life of a car. The
most usual reason for a coil to fail is after
being left with the ignition switched on but the
engine not running. There is then constant
current flowing, instead of the intermittent
flow when the contact breaker is opening. The
coil then overheats, and the insulation is
damaged (photo).
2If the coil seems suspect after fault finding,
the measurement of the resistance of the
primary and secondary windings (usually an
ohmmeter) can establish its condition. If an
ohmmeter is not available, it will be necessary
to try a new coil.
9 Digiplex (electronic) ignition
- location of components and
precautions
1The main components of this system are
located within the engine compartment as
shown.
2On cars equipped with this system, it is
4•6 Ignition system
Fig. 4.7 Main components of Digiplex ignition system (Sec 9)8.1 Ignition coil
Fig. 4.6 Exploded view of typical Ducellier distributor (Sec 7)
1 Cap
2 Rotor
3 Movable breaker arm
4 Vacuum advance link
5 Fixed contact breaker arm
6 Contact breaker baseplate
7 Cam assembly8 Centrifugal advance weight
control springs
9 Driveshaft and plate
10 Body
11 LT insulator
12 Condenser
13 Vacuum capsule14 Cap retaining spring
15 Thrust washer
16 Spacer washer
17 Driving dog
18 Retaining pin
19 Felt pad
7.13 Marelli distributor centrifugal weights
and springs
1 Control unit
2 Cut-out control unit
3 Ignition coil
4 Flywheel (engine
speed) sensor
5 Crankshaft pulley
(TDC) sensor
6 Vacuum hose

Fault finding - mechanical breaker ignition system
Ignition system 4•9
4
Engine fails to start
m mLoose battery connections
m mDischarged battery
m mOil in contact points
m mDisconnected ignition leads
m mFaulty condenser
Engine overheats, lacks power
m
mSeized distributor weights
m mPerforated vacuum pipe
m mIncorrect ignition timing
Engine starts and runs but misfires
m
mFaulty spark plug
m mCracked distributor cap
m mCracked rotor arm
m mWorn advance mechanism
m mIncorrect spark plug gap
m mIncorrect contact points gap
m mFaulty condenser
m mFaulty coil
m mIncorrect timing
m mPoor engine/transmission earth connections
Fault finding - Digiplex (electronic) ignition system
Engine fails to start
m
mExcessive gap on TDC sensor
m mTDC or engine speed sensor short circuited or earthed
m mDefective ignition control unit
m mControl unit multi-plug contacts corroded
m mDefective coil
Engine lacks power, high fuel consumption
m
mIncorrect ignition advance
m mTDC sensor incorrectly set
m mDistributor vacuum hose blocked