1983 FIAT UNO alternator

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carrier assembly withdrawn (photo).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

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

prevent the flywheel turning. Fit the engine
endplate (photo).
20Fit the timing belt sprocket to the front
end of the crankshaft (photo).
21Fit the crankshaft pulley and the nut;
tighten it to the specified torque, again
jamming the starter ring gear to prevent the
crankshaft from rotating (photo).
Cylinder head
22Refitting is described in Section 29.
Camshaft carrier and camshaft
23Refitting is described in Section 27.
Timing belt and tensioner
24Refitting is described in Section 28, but
make sure that the belt cover rear plate is
bolted into position. If the engine mounting
bracket was removed, bolt it into positioncomplete with the tensioner plunger to
provide spring pressure to the belt pulley
(photos).
Valve clearances
25Check the valve clearances as described
in Section 26.
26Using new gaskets, bolt on the camshaft
carrier cover plate and the inlet and exhaust
manifolds using new gaskets. Fit the exhaust
manifold hot air collector plate (photo).
27Locate the engine rear plate on its dowels
by sliding it behind the flywheel (photo).
43 Engine ancillaries- refitting
1Bolt on the carburettor (Chapter 3). 2Fit the coolant pump and thermostat
housing (Chapter 2).
3Fit the alternator and tension the drivebelt
(Chapters 9 and 2).
4Fit the distributor (Chapter 4).
5Fit the fuel pump (Chapter 3).
6Fit the clutch (Chapter 5).
7Fit a new oil filter cartridge (Section 2 of this
Chapter).
44 Engine/transmission-
reconnection and refitting
3
1Offer the transmission to the engine making
sure that the clutch has been centralised as
described in Chapter 5 (photo).
1•32 1116 cc and 1301 cc engine
44.1 Offering transmission to engine42.27 Engine rear plate42.26 Tightening a camshaft carrier cover
nut
42.24C Engine mounting bracket with belt
tensioner plunger (arrowed)
42.24B Belt cover mounting stud42.24A Belt cover rear plate
42.21 Crankshaft pulley and nut42.20 Fitting crankshaft timing belt
sprocket42.19 Tightening flywheel bolts

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

2
System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “No loss” with radiator and integral expansion tank. Electric cooling
fan, belt-driven coolant pump, thermostat on cylinder head
General
Radiator fan cuts in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 to 94ºC (194 to 201ºF)
Radiator fan switches off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 to 89ºC (185 to 192ºF)
Thermostat opens:
903 cc engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 to 89ºC (185 to 192ºF)
1116 cc and 1301 cc engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 to 87ºC (181 to 188.6ºF)
Fully open:
903 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100ºC (212ºF)
1116 cc and 1301 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95ºC (203ºF)
Expansion tank pressure cap rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.78 bar (11 lbf/in2)
Coolant
Capacity:
903 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 litre (8.1 pint)
1116 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 litre (10.6 pint)
1301 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 litre (10.9 pint)
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ethylene glycol based antifreeze
Torque wrench settingsNm lbf ft
Temperature sender switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Coolant pump mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 25
Alternator adjuster and mountings nuts . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Chapter 2 Cooling and heating systems
For modifications, and information applicable to later models, see Supplement at end of manual
Coolant mixtures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Coolant pump - removal, overhaul and refitting . . . . . . . . . . . . . . . . 9
Cooling system - draining, flushing and refilling . . . . . . . . . . . . . . . . 2
Cooling system sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Description and maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Drivebelt - tensioning and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Fault finding - cooling and heating . . . . . . . . . . . . See end of ChapterHeater - dismantling, overhaul and reassembly . . . . . . . . . . . . . . . . 13
Heater unit - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Heating and ventilation system - description . . . . . . . . . . . . . . . . . . 11
Radiator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Radiator fan thermostatic switch - removal, checking and refitting . 5
Radiator fan - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 6
Thermostat - removal, testing and refitting . . . . . . . . . . . . . . . . . . . . 4
2•1
Specifications Contents
1 Description and
maintenance
1
1The cooling system consists of a
front-mounted radiator with built-in expansion
tank, a coolant pump (belt-driven from the
crankshaft pulley) and a thermostatically-
controlled electric cooling fan.
2In order to assist rapid warm-up, athermostat is located in a housing at the
left-hand end of the cylinder head. The hose
connections to the thermostat housing vary
according to model.
3The heater is supplied with coolant from the
engine and incorporates a matrix and blower
with the necessary controls.
4The throttle valve plate block of the
carburettor is coolant-heated as a means of
improving fuel atomisation.
5Maintenance is minimal as in theory no
coolant should ever be lost from theexpansion tank. Regularly check that the
coolant level is between 50.0 and 70.0 mm
(1.97 and 2.8 in) above the MIN mark on the
tank with the engine cold. The need for
regular topping up will indicate a leak
somewhere in the system. If one cannot be
found suspect an internal leak in the engine
although this is usually confirmed by a rise in
the engine oil level and water on the dipstick
(photo). Any topping-up should be done using
an antifreeze mixture (see Section 3), not plain
water.
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321

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

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

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