1983 FIAT UNO coolant

Fault finding - cooling and heating systems
2•8 Cooling and heating systems
Overheating
m mInsufficient coolant in system
m mPump ineffective due to slack drivebelt
m mRadiator blocked either internally or externally
m mKinked or collapsed hose causing coolant flow restriction
m mThermostat not working properly
m mEngine out of tune
m mIgnition timing retarded or auto advance malfunction
m mCylinder head gasket blown
m mEngine not yet run-in
m mExhaust system partially blocked
m mEngine oil level too low
m mBrakes binding
Engine running too cool
m
mFaulty, incorrect or missing thermostat
Loss of coolant
m
mLoose hose clips
m mHoses perished or leaking
m mRadiator leaking
m mFiller/pressure cap defective
m mBlown cylinder head gasket
m mCracked cylinder block or head
Heater gives insufficient output
m
mEngine overcooled (see above)
m mHeater matrix blocked
m mHeater controls maladjusted or broken
m mHeater control valve jammed or otherwise
defective

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

3The centralised door locking system can
operate independently of the key.
4To gain access to the lock solenoid and
linkage, remove the front door trim panel as
described in Chapter 12.
5Disconnect the battery negative lead.
6Disconnect the electrical wiring plugs from
the solenoid within the door cavity.
7Disconnect the solenoid from the lock lever
by removing the clip.
8Unscrew the two bolts which secure the
solenoid to the door and remove it.
9Renew the solenoid or switch as necessary.
10Refitting is a reversal of removal.
11Refer to Section 10 for details of system
fuses and relays.
33 Economy gauge
(Econometer)
2
1This device is fitted to ES (energy saving)
models and indicates to the driver the fuel
consumption (in litres per 100 km) coupled
with a needle which moves over coloured
sections of a dial to make the driver aware
that his method of driving is either conducive
to high or low fuel consumption. Refer to
Chapter 3, Section 16.
2The device is essentially a vacuum gauge
which also incorporates a warning lamp to
indicate to the driver when a change of gear is
required.
3A fuel cut-out valve (see Chapter 3, Sec-
tion 11) is used in conjunction with the
economy gauge so that when the accelerator
pedal is released during a pre-determined
engine speed range, fuel supply to the engine
is stopped, but resumes when the engine
speed falls below the specified range.
LED (light emitter diode)
4The gearchange indicator will only light up
at engine speeds in excess of 2000 rev/min
for vacuum pressures up to 600 mm Hg in 1st,
2nd and 3rd speed gears and for vacuum
pressures up to 676 mm Hg in 4th speedgear. The light will not come on if 5th speed
gear is engaged or if the coolant temperature
is below 55ºC.
5There is a two second delay in the light
coming on to prevent it operating during rapid
acceleration in a low gear.
6If the LED light comes on during
deceleration it should be ignored.
Fault finding
7A faulty economy gauge should be checked
in the following way.
8Refer to Section 21 and remove the
instrument panel.
9Disconnect the economy gauge L
connector and then connect a test lamp
between the BN cable contact and earth. If
the lamp comes on then the gauge supply
circuit is not open. If the lamp does not come
on, check all connections in the supply cable
which comes from the interconnecting unit of
the electrical system, also Fuse No 12.
10Now connect a voltmeter between the
white cable and earth. Check the voltage with
the engine not running, but the ignition
switched on. It should be between 0.7 and
0.9 volt. If the reading varies considerably
from that specified, check the connections
between the economy gauge and the fuel
cut-out device control unit. If the fault cannot
be rectified, renew the ignition control unit
(Digiplex system, see Chapter 4).
11Now check the closed throttle valve plate
switch by connecting a voltmeter between the
brown and BN cables of the L connector. With
the valve plate open, there should be no
reading, but with it open, voltage should be
indicated.
12Failure to conform as described will be
due to a faulty earth in the switch or a faulty
fuel cut-out device control unit.
13A further test of the throttle valve plate
switch may be carried out by disconnecting
the multi-plug from the fuel cut-out device
control unit.
14Connect a test lamp to contact 4 (positive
battery terminal). The lamp should come on,
when the engine is idling or the accelerator
released. If it does not, renew the throttle
valve plate switch.15Connect a tachometer to the brown/white
cable contact in the L connector and record
the engine speed with the engine running. If
no reading is obtained, renew the Digiplex
ignition control unit which must be faulty.
34 Check control (warning
module) system
2
1This is fitted into the instrument panel of
certain models to provide a means of
checking the operation of many electrical
circuits and other systems in the interest of
safety. Sensors are used where appropriate.
2The following components are not
monitored by the system, but have separate
warning lamps:
Handbrake “on”
Choke in use
Low engine oil pressure
Battery charge indicator
3The multi-functional electronic device
automatically checks the following functions
whether the engine is running or not:
Coolant level
Disc pad wear
Door closure
Engine oil level
Front parking lamps
Rear foglamps
Stop lamps
4The check information is stored by the
system monitor until the engine is started
when the display panel then indicates the
situation by means of the LEDs (light emitter
diodes) and the general lamp.
5If all functions are in order, the green panel
lamp will come on when the ignition key is
turned and will go out after two to three
seconds.
6If some functions are not in order, then the
red panel lamp will come on also the
appropriate LED.
Sensors - checking
7If a fault signal occurs which is
subsequently found to be incorrect, first
check the wiring connections between the
9•12 Electrical system
Fig. 9.15 Check system control panel (Sec 34)
A Parking lamps
B Coolant levelC Engine oil level
D Door closureE Brake fluid level
F Disc pad wearFig. 9.14 Location of control units (Sec 33)
A Digiplex ignition system control unit
B Fuel cut-out valve control unit

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

Valve timing clearance:
999 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 mm
1108 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.70 mm
1372 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.80 mm
Valve timing:Inlet Exhaust
999 cc:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1º BTDC 29º BBDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19º ABDC 9º ATDC
1108 cc:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2º BTDC 42º BBDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19º ABDC 2º ATDC
1116 cc:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7º BTDC 37º BBDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35º ABDC 5º ATDC
1299/1301 cc:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9º BTDC 39º BBDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31º ABDC 1º ATDC
1299/1301 cc Turbo ie:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0º TDC 30º BBDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40º ABDC 10º ATDC
1372 cc ie:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7º BTDC 37º BBDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35º ABDC 5º ATDC
1372 cc Turbo ie:
Opens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14º BTDC 36º BBDC
Closes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44º ABDC 6º ATDC
Cam lift:
999 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1 mm
1108 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.0 mm
1116 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8 mm
1299/1301 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.0 mm
1372 cc ie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8 mm
1372 cc Turbo ie
Inlet valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.5 mm
Exhaust valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8 mm
Supplement: Revisions and information on later models 13•5
13
View of engine compartment (air
cleaner removed) on the 999 cc
FIRE engined model
1 Wiper motor cover
2 Suspension strut turret
3 Brake hydraulic fluid reservoir
4 Carburettor
5 Washer fluid reservoir
6 Right-hand engine mounting
7 Fuel pump
8 Ignition distributor
9 Ignition coil
10 Headlamp
11 Oil filler cap
12 Battery
13 Radiator cooling fan
14 Coolant filler/expansion tank
15 Radiator

View of front end from below on
the 999 cc FIRE engined model
1 Left hand front engine mounting
2 Transmission
3 Track control arm
4 Driveshaft
5 Left hand rear (lower) engine
mounting
6 Gearchange rods
7 Exhaust pipe
8 Oil filter cartridge
9 Brake caliper
10 Sump pan drain plug
View of engine compartment on
the 1301 cc Turbo ie engined
model
1 Alternator air cooling intake
2 Washer fluid reservoir cap
3 Suspension strut turret
4 Secondary fuel filter
5 Fuel supply hose
6 Coolant expansion tank
7 Brake fluid reservoir cap
8 Ignition system ECU
9 Inlet manifold
10 Excessive pressure switch
11 Air cleaner
12 Timing belt cover
13 Fuel pressure regulator
14 Airflow meter
15 Throttle position switch
16 Air intake duct
17 Air intake to throttle valve
housing
18 Engine oil filler cap
19 Radiator cooling fan
20 Headlamp dim-dip transformer
21 Intercooler air duct
22 Ignition distributor
23 Headlamp
24 Main idle speed adjusting screw
25 Base setting idle speed screw
13•6 Supplement: Revisions and information on later models

Supplement: Revisions and information on later models 13•7
View of engine compartment (air
cleaner removed) on the
1372 cc ie engined model
1 Engine oil level dipstick
2 Timing belt cover
3 Engine mounting (right-hand)
4 Clutch master cylinder fluid
reservoir
5 Fuel supply and return hoses
6 Injection unit
7 Inlet manifold
8 Washer reservoir
9 Brake master cylinder and fluid
reservoir
10 Injection system fuse/relay block
11 Suspension strut turret
12 Ignition coil
13 Ignition system ECU
14 Battery
15 Coolant filter expansion tank
16 Ignition distributor
17 Radiator cooling fan
18 Engine oil filler cap
19 Starter motor
20 Oil filter
View of front end from below on
the 1031 cc Turbo ie engined
model
1 Anti-roll bar
2 Exhaust pipe
3 Track control arm
4 Engine centre mounting
5 Gearchange rods
6 Brake caliper
7 Left-hand driveshaft
8 Intermediate driveshaft
9 Right-hand driveshaft
10 Transmission
11 Engine oil drain plug
12 Auxiliary lamp
13 Horn
14 Intercooler
15 Starter motor
16 Oil filter cartridge
17 Oil pressure sender unit
18 Engine oil cooler
19 Right-hand underwing shield
20 Left-hand underwing shield
13

Lubrication system
Oil pump type:
999/1108 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gear driven from front of crankshaft.
1372 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pump operated from front of crankshaft. Oil pressure relief valve in
front cover.
Tooth tip-to-body clearance (999/1108 cc) . . . . . . . . . . . . . . . . . . . . . . 0.080 to 0.186 mm
Gear endfloat:
999/1108 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 to 0.056 mm
1372 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.106 mm
Oil pressure (at normal operating temperature) . . . . . . . . . . . . . . . . . . . 3.4 to 4.9 bars
Oil filter:
999/1108 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion F107
1372 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion C106
Torque wrench settingsNm lbf ft
Auxiliary shaft sprocket bolt (1372 cc) . . . . . . . . . . . . . . . . . . . . . . . . . . 83 62
Big-end cap bolts:
999/1108 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 30
1372 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 38
Camshaft bearing cap bolts:
M8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 14
M6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
Camshaft cover screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
Camshaft housing to lower cylinder head securing bolt (1372 cc) . . . . . 20 15
Camshaft housing to inlet manifold bracket bolt (1372 cc) . . . . . . . . . . 25 18
Camshaft sprocket bolt
999/1108 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 50
1372 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 62
Centre mounting to final drive casing bracket (1201/1301 cc) . . . . . . . . 23 17
Coolant temperature switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Crankshaft pulley bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Crankshaft pulley nut (1372 cc) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 145
Crankshaft rear oil seal retainer bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
Crankshaft sprocket bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 58
13•8 Supplement: Revisions and information on later models
View of front end from below on
the 1372 cc ie engine model
1 Oil filter
2 Engine oil drain plug
3 Starter motor
4 Horns
5 Transmission front mounting
6 Front fog lamp and adjuster
7 Driveshaft
8 Transmission rear mounting
9 Gearchange linkage
10 Exhaust downpipe and system
joint
11 Anti-roll bar
12 Track control arm
13 Tie-rod balljoint
14 Brake unit
15 Driveshaft damper
16 Underwing shield