1983 FIAT UNO spark plugs

4
System type
Except ES engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Battery, coil mechanical breaker distributor
ES engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Marelli Digiplex electronic with breakerless distributor
Firing order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 3 - 4 - 2 (No. 1 cylinder at crankshaft pulley end)
Mechanical breaker distributor
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Marelli or Ducellier
Contact breaker points gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.37 to 0.43 mm (0.015 to 0.017 in)
Condenser capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20 to 0.25 µF
Dwell angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 to 58º
Rotor rotational direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clockwise
Ignition timing (dynamic)
903 cc engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5º BTDC at idle
1116 and 1301 cc engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10º BTDC at idle
Centrifugal advance:
903 cc engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Between 30 and 34º max
1116 and 1301 cc engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Between 22 and 24º max
Vacuum advance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Between 10 and 14º max
Ignition coil
Primary winding resistance at 20ºC (68ºF) . . . . . . . . . . . . . . . . . . . . . . . Between 2.6 and 3.3 ohms depending upon make of coil
Secondary winding resistance at 20ºC (68ºF) . . . . . . . . . . . . . . . . . . . . Between 6745 and 12 000 ohms depending upon make of coil
Marelli Digiplex electronic ignition
Rotor arm resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000 ohms
Advance range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Between 6 to 10º and 47 to 51º
Engine speed sensor
Resistance on flywheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 612 to 748 ohms
Sensor to flywheel tooth gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.25 to 1.3 mm (0.0099 to 0.0512 in)
TDC sensor
Resistance on pulley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 612 to 748 ohms
Sensor to pulley tooth gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 to 1.0 mm (0.016 to 0.039 in)
Ignition coil
Primary winding resistance at 20ºC (68ºF) . . . . . . . . . . . . . . . . . . . . . . . 0.310 to 0.378 ohms
Secondary winding resistance at 20ºC (68ºF) . . . . . . . . . . . . . . . . . . . . 3330 to 4070 ohms
Chapter 4 Ignition system
For modifications and information applicable to later models, see Supplement at end of manual
Condenser (capacitor) - removal, testing and refitting . . . . . . . . . . . 5
Digiplex (electronic) - ignition checks and adjustments . . . . . . . . . . 10
Digiplex (electronic) ignition - location of components and
precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Distributor - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Distributor (mechanical breaker type) - overhaul . . . . . . . . . . . . . . . 7
Dwell angle - checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Fault finding - ignition system . . . . . . . . . . . . . . . . See end of Chapter
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Ignition coil - (mechanical breaker ignition) . . . . . . . . . . . . . . . . . . . . 8
Ignition switch - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 12
Ignition timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Mechanical contact breaker - points servicing . . . . . . . . . . . . . . . . . 2
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4•1
Specifications Contents
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

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)

important that the following precautions are
observed.
3Never start the engine if the battery leads
are loose.
4Do not stop the engine by pulling off a
battery lead.
5Remove the control unit if ambient
temperature (paint drying oven) is above 80ºC
(176ºF).
6Never connect or disconnect the multi-plug
at the control unit unless the ignition is
switched off.
7Disconnect the battery negative lead before
carrying out electric body welding.10 Digiplex (electronic) ignition
- checks and adjustments
3
1Without special equipment, any work on the
system components should be restricted to
the following.
Engine speed sensor
2The gap between the sensor and the teeth
of the flywheel should be between 0.25 and
1.3 mm (0.0099 to 0.0512 in). Any
deviation will be due to mechanical damage to
the sensor, no adjustment being possible.
TDC sensor
3The gap between the sensor and one of the
TDC reference marks on the crankshaft pulley
should be between 0.4 and 1.0 mm (0.016 to
0.039 in).
4Any deviation will be due to the sensor
plate becoming loose. To reposition it will
necessitate setting No. 1 piston at TDC which
can only be carried out accurately by your
dealer using special tools.
Supply circuit and continuity of
coil primary winding
5Connect a test lamp between contacts 11
and 9 of the multi-plug having first pulled it
from the control unit.
6Switch on the ignition, the test lamp should
come on. If it does not, either the connection
at the positive pole of the control unit or the
coil primary winding is open.
Control unit earth
7Connect a test lamp between contacts 8
and 9 of the multi-plug having first pulled it
from the control unit. Switch on the ignition,
the test lamp should come on. If it does not,
improve the earth connection.
11 Spark plugs
1
1The correct functioning of the spark plugs is
vital for the correct running and efficiency of the
engine. It is essential that the plugs fitted are
appropriate for the engine, and the suitable type
is specified at the beginning of this chapter. If
Ignition system 4•7
Fig. 4.9 Digiplex control unit (Sec 9)
1 Vacuum hose connector
2 Multi-plug socket
1 Control unit
2 Distributor
3 Ignition coil4 TDC sensor
5 Wiring connector plug6 Engine speed sensor
7 Wiring connector plug
Fig. 4.8 Location of Digiplex ignition system components (Sec 9)
Fig. 4.13 Test lamp connected between
terminals 8 and 9 of control unit multi-plug
(Sec 10)Fig. 4.12 Test lamp connected between
terminals 11 and 9 of control unit
multi-plug (Sec 10)
Fig. 4.11 TDC sensor gap (Sec 10)
Fig. 4.10 Engine speed sensor gap
(Sec 10)
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.

Cooling system................................................................................. 8
Part A: 999 cc engine
Description
Maintenance
Thermostat - removal and refitting
Coolant pump - removal and refitting
Part B: 1301 cc Turbo ie engine
Description
Part C: 1372 cc ie and 1372 cc Turbo ie engines
Description
Maintenance
Cooling system - draining, flushing and refilling
Radiator (and cooling fan) - removal and refitting
Thermostat - removal and refitting
Coolant pump - removal and refitting
Coolant pump/alternator drivebelt - checking, renewal and
tensioning
Part D: Heater unit later models
Heater unit - removal and refitting
Heater unit - dismantling and reassembly
Fuel and exhaust systems............................................................... 9
Part A: General
Unleaded fuel
Air cleaner modified types
Fuel pump (999 cc engine) - description, removal and
refitting
Fuel tank (999 cc engine)
Part B: Carburettor models
Carburettor (Weber 32 TLF) - description
Carburettor (Weber 32 TLF) - idle speed and mixture
Carburettor (Weber 32 TLF) - removal and refitting
Carburettor (Weber 32 TLF) - overhaul
Carburettor (Weber 30/32 DMTE) - general
Carburettor (Weber 30/32 DMTE) - overhaul
Carburettor (Weber 32 ICEV 61/250 and DMTE 30/32,
DMTE 30/150) - general
Carburettor (Solex C 30/32-CIC 8) - description
Part C: Bosch LE-2 Jetronic fuel injection system
Description
Maintenance
Fuel filter - renewal
Air cleaner element - renewal
Idle speed and mixture - adjustment
Fuel injection system - electrical tests
Fuel injection system - mechanical tests
Fuel injection system components - removal and
refitting
Throttle control linkage - general
Fuel tank - general
Part D: Bosch Mono-Jetronic fuel injection system
Description
Maintenance
Fuel filter - renewal
Air cleaner element - renewal
Idle speed and mixture adjustment
Accelerator control system - check and adjustment
Fuel system - depressurisation
Fuel pump and supply - system checks
Fuel pump - removal and refitting
Injector unit - removal and refitting
Intake air temperature sensor - removal and refitting
Fuel injector - removal and refitting
Electronic control unit (ECU) - removal and refitting
Inlet manifold - removal and refitting
Exhaust manifold - removal and refitting
Catalytic converter - general information
Fuel evaporation control system - generalPart E: Bosch L3.1/2 Jetronic fuel injection systems
Description
Fuel system - depressurisation
Maintenance
Fuel filter - renewal
Air cleaner element - renewal
Checks and adjustments
Injection system components - removal and refitting
Part G: Turbocharger system
Description
Precautions
Turbocharger (1301 cc ie engine) - removal and refitting
Turbocharger (1372 cc ie engine) - removal and refitting
Intercooler - removal and refitting
Injector cooling fan - removal and refitting
Fault finding - fuel injection system
Fault finding - turbocharger system
Ignition system................................................................................. 10
General
Ignition timing (all later models)
Breakerless ignition system - description
Distributor (breakerless type) - removal and refitting
Distributor (breakerless type) - overhaul
Breakerless ignition system components - testing
Microplex ignition system - description
Distributor (Microplex) - removal and refitting
Microplex ignition system components - testing
Digiplex 2 ignition system - description
Distributor (Digiplex 2) - removal and refitting
Spark plugs and HT leads - general
Fault finding - Microplex ignition system
Clutch................................................................................................ 11
Clutch pedal adjustment (cable clutch)
Hydraulic clutch - description
Maintenance (hydraulic clutch)
Clutch master cylinder - removal, overhaul and
refitting
Clutch operating cylinder - removal, overhaul and
refitting
Clutch hydraulic system - bleeding
Transmission.................................................................................... 12
Part A: 1301 cc Turbo ie engine
Description
Gearchange linkage - removal and refitting
Gearchange linkage (Antiskid models) - general
Final drive output shafts - description and oil seal
renewal
Part B: 1372 cc ie and 1372 cc Turbo ie engines
Description
Maintenance
Oil level - checking
Oil - renewal
Gearlever and linkages - general
Transmission - removal and refitting
Part C: 999 and 1108 cc with C514 type transmission
Description
Maintenance
Driveshafts........................................................................................ 13
Inboard joint boots (non-Turbo models, September 1987 on) -
modification
Intermediate driveshaft (Turbo ie models)
Inboard CV joints (Turbo ie models - overhaul
Right-hand driveshaft damper weight (1108 and 1372 cc
models) - removal and refitting
13•2 Supplement: Revisions and information on later models

13•18 Supplement: Revisions and information on later models
Every 9000 miles (15 000 km) or
12 months (whichever comes first)
m mCheck the tyre pressures and their condition
(including the spare)
m mWhere a pad wear warning light is fitted, check its
operation
m mCheck the front brake disc pads for excessive wear
m mCheck the underbody condition (fuel and brakes
pipes, exhaust system, hoses, bushes and gaiters)
m mCheck the condition and tension of drivebelts
m mCheck the engine idle speed and CO emissions
m mCheck the EGR system (If fitted)
m mCheck fluid levels (coolant, brake fluid and
windscreen washer)
m mRenew spark plugs (1372 cc Turbo models)
m mRenew the engine oil and oil filter (non-Turbo
models)
m mCheck the HT leads and connections
m mCheck the condition of all coolant, fuel and
hydraulic hoses and connections
Every 18 000 miles (30 000 km) or
24 months (whichever comes first)
In addition to the items listed for 9000 mile (15 000 km) or 12 months
service
m mCheck the rear brake disc pads for wear (where
applicable)
m mCheck/adjust the valve clearances
m mCheck and tighten (if necessary), inlet and exhaust
manifolds
m mCheck the clutch adjustment (cable operated
models)
m mRenew the fuel filter (where applicable)
m mRenew the air cleaner element
m mRenew the spark plugs and check the HT leads
and connections (all models)
m mWhere applicable, have the ignition and injection
systems checked (special equipment needed)
m mRenew coolant
m mRenew brake fluid
Every 28 000 miles (45 000 km) or
36 months (whichever comes first)
In addition to the items listed for 9000 mile (15 000 km) or 12 months
service
m mCheck Lambda (oxygen) sensors operation (special
equipment needed)
m mCheck fuel evaporation system (where fitted)
m mCheck the transmission oil level
m mCheck the condition crankcase ventilation system
Every 37 000 miles (60 000 km) or
48 months (whichever comes first)
In addition to the items listed for 18 000 mile (30 000 km) or
24 months service
m mCheck the condition of the rear brake shoe linings
m mCheck the condition of the timing belt
Every 65 000 miles (105 000 km)
m
mRenew the timing belt
Every 74 500 miles (120 000 km)
m
mRenew the manual transmission oil
Every 250 miles (400 km), weekly or
before a long journey
m mProceed as described for the earlier models at the
start of this manual
Every 6000 miles (10 000 km) or
12 months (whichever comes first)
m mRenew the engine oil and oil filter (Turbo models
only)
3 Routine maintenance- all models from June 1991
The maintenance intervals in this manual are provided with the
assumption that you, not the dealer, will be carrying out the work.
These are the minimum maintenance intervals recommended by us, for
vehicles driven daily. If you wish to keep your vehicle in peak condition
at all times, you may wish to perform some of these procedures more
often. We encourage frequent maintenance, since it enhances the
efficiency, performance and resale value of your vehicle.
If the vehicle is driven in dusty areas, used to tow a trailer, or driven
frequently at slow speeds (idling in traffic) or on short journeys, more
frequent maintenance intervals are recommended.
When the vehicle is new, it should be serviced by an authorised
dealer to preserve the factory warranty.

mounted on the front end of the crankshaft
and driven by it.
11The flexible toothed timing belt drives thecamshaft and the coolant pump from a
sprocket on the front end of the crankshaft.
The belt is tensioned by an
eccentrically-mounted pulley.
12The distributor and the fuel pump
(carburettor models) are driven from the
flywheel end of the camshaft. The fuel pump
on fuel injection models is an integral unit
combined with the fuel gauge sender unit and
immersed in the fuel tank.
PART B:
OPERATIONS POSSIBLE
WITH ENGINE IN CAR
Valve clearances - adjustment
1The operations are similar to those
described in Chapter 1, Section 26, but note
that the special tools referred to have differentpart numbers for the FlRE engine -
1860443000 and 1887001000 (photos).
2Remember that the clearance for inlet and
exhaust valves differs see Specifications at
the beginning of this Supplement.
3Counting from the timing cover end of the
engine, the valve sequence is as follows.
Inlet 2-4-5-7
Exhaust 1-3-6-8
Timing belt - renewal #
4Remove the air cleaner.
5Slacken and remove the alternator
drivebelt, then remove the spark plugs.
6Unbolt and remove the timing belt cover.
Note the bolt located at the bottom of the
cover, this can be easily overlooked (photo).
7Unbolt and remove the crankshaft pulley
(photo).
13•20 Supplement: Revisions and information on later models
5B.7 Unscrewing the crankshaft pulley
bolts5B.6 Timing cover lower fixing bolt
removal5B.1B Using a modified C-spanner and
screwdriver to remove a shim
5B.1A Checking a valve clearance
Fig. 13.3 Longitudinal sectional view of the 999 and 1108 cc
engine (Sec 5A)Fig. 13.4 999 and 1008 cc engine lubrication system (Sec 5A)

8Turn the crankshaft sprocket bolt, or
engage top gear and raise and turn a front
roadwheel, until the camshaft sprocket TDC
timing mark is aligned with the mark on the
cylinder head and the crankshaft sprocket
timing mark is aligned with the mark on the oil
pump cover (photos).
9Release the nut on the timing belt
tensioner, move the pulley away from the belt
and retighten the nut to hold the pulley in the
retracted position (photo).
10Slide the drivebelt from the sprockets.
11When refitting the new belt, make sure
that the sprocket timing marks are still in
alignment and fit the belt so that the arrows
on the belt point in the direction of engine
rotation, and the lines of the belt coincide with
the sprocket marks.
12Engage the timing belt with the crankshaft
sprocket first, then place it around the coolant
pump sprocket and the camshaft sprocket
(photo). Finally slip the belt around the
tensioner pulley.
13Release the tensioner nut and push the
pulley against the belt until the belt is quite
taut. Check that the sprocket timing marks
have not moved out of alignment. If they have,
reset them by moving them over the belt
teeth.
14Still applying force to the pulley, tighten its
nut.
15Turn the crankshaft through two complete
turns in the normal direction of rotation and
check that when the centre of the longest runof the belt is gripped between finger and
thumb it can just be twisted through 90º. If
increased tension is required to achieve this,
release the tensioner nut and prise the pulley
against the timing belt. 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.
16Refit the timing belt cover, the crankshaft
pulley, alternator drivebelt, spark plugs and
the air cleaner.
Camshaft -
removal and refitting#
Warning: Refer to the beginning
of Section 9 before starting any
work.
17Remove the air cleaner and the fuel pump(carb. models), as described in Section 9 of
this Supplement.
18Remove the distributor (Section 10).
19Remove the timing belt cover.
20Unbolt and remove the camshaft cover,
having first disconnected the HT lead clip
(photos).
21Turn the crankshaft (by engaging top gear
and raising and turning a front roadwheel)
until No. 4 piston is at TDC. The timing mark
on the camshaft sprocket will be in alignment
with the mark on the cylinder head.
22Pass a rod through one of the holes in the
camshaft sprocket to prevent it rotating and
then unscrew the sprocket fixing bolt. Slip the
sprocket from the camshaft and out of the
loop of the belt (photos).
23Mark the camshaft bearing caps as to
position and then unbolt and remove the
Supplement: Revisions and information on later models 13•21
5B.9 Releasing the timing belt tensioner
nut5B.8B Crankshaft sprocket timing mark
and oil pump cover alignment mark
(arrowed)5B.8A Camshaft sprocket timing mark and
cylinder head timing mark in alignment
5B.22B Camshaft sprocket bolt and
washer5B.22A Unscrewing the camshaft sprocket
bolt
5B.20A Camshaft cover HT lead clip5B.12 Fitting the timing belt
5B.20B Removing the camshaft cover
13