heating FIAT UNO 1983 Service Owner's Manual

Engine cuts out suddenly –
ignition fault
m mLoose or disconnected LT wires
m mWet HT leads or distributor cap (after
traversing water splash)
m mCoil failure (check for spark)
m mOther ignition fault (see Chapter 4)
Engine misfires before cutting out
– fuel fault
m mFuel tank empty
m mFuel pump defective or filter blocked
(check for delivery)
m mFuel tank filler vent blocked (suction will be
evident on releasing cap)
m mCarburettor needle valve sticking
m mCarburettor jets blocked (fuel contami-
nated)
m mOther fuel system fault (see Chapter 3)
Engine cuts out – other causes
m
mSerious overheating
m mMajor mechanical failure (eg camshaft
drive)
Ignition (no-charge) warning light
illuminated
m mSlack or broken drivebelt — retension or
renew (Chapter 9)
Ignition warning light not
illuminated
m mCoolant loss due to internal or external
leakage (see Chapter 2)
m mThermostat defective
m mLow oil level
m mBrakes binding
m mRadiator clogged externally or internally
m mElectric cooling fan not operating correctly
m mEngine waterways clogged
m mIgnition timing incorrect or automatic
advance malfunctioning
m mMixture too weak
Note: Do not add cold water to an overheated
engine or damage may result
Note: Low oil pressure in a high-mileage
engine at tickover is not necessarily a cause
for concern. Sudden pressure loss at speed is
far more significant. In any event check the
gauge or warning light sender before
condemning the engine.
Gauge reads low or warning light
illuminated with engine running
m mOil level low or incorrect grade
m mDefective gauge or sender unit m mWire to sender unit earthed
m mEngine overheating
m mOil filter clogged or bypass valve defective
m mOil pressure relief valve defective
m mOil pick-up strainer clogged
m mOil pump worn or mountings loose
m mWorn main or big-end bearings
Pre-ignition (pinking) on
acceleration
m mIncorrect grade of fuel
m mIgnition timing incorrect
m mDistributor faulty or worn
m mWorn or maladjusted carburettor
m mExcessive carbon build-up in engine
Whistling or wheezing noises
m
mLeaking vacuum hose
m mLeaking carburettor or manifold gasket
m mBlowing head gasket
Tapping or rattling
m
mIncorrect valve clearances (where appli-
cable)
m mWorn valve gear
m mWorn timing chain or belt
m mBroken piston ring (ticking noise)
Knocking or thumping
m
mUnintentional mechanical contact (eg fan
blades)
m mWorn drivebelt
m mPeripheral component fault (generator,
water pump, etc)
m mWorn big-end bearings (regular heavy
knocking, perhaps less under load)
m mWorn main bearings (rumbling and
knocking, perhaps worsening under load)
m mPiston slap (most noticeable when cold)
Engine noises
Low engine oil pressure
Engine overheatsEngine cuts out and will not restart
Fault FindingREF•11
REF
Crank engine and check for spark. Note
use of insulated tool

REF•16Glossary of Technical Terms
RotorIn a distributor, the rotating device
inside the cap that connects the centre
electrode and the outer terminals as it turns,
distributing the high voltage from the coil
secondary winding to the proper spark plug.
Also, that part of an alternator which rotates
inside the stator. Also, the rotating assembly
of a turbocharger, including the compressor
wheel, shaft and turbine wheel.
RunoutThe amount of wobble (in-and-out
movement) of a gear or wheel as it’s rotated.
The amount a shaft rotates “out-of-true.” The
out-of-round condition of a rotating part.
SSealantA liquid or paste used to prevent
leakage at a joint. Sometimes used in
conjunction with a gasket.
Sealed beam lampAn older headlight design
which integrates the reflector, lens and
filaments into a hermetically-sealed one-piece
unit. When a filament burns out or the lens
cracks, the entire unit is simply replaced.
Serpentine drivebeltA single, long, wide
accessory drivebelt that’s used on some
newer vehicles to drive all the accessories,
instead of a series of smaller, shorter belts.
Serpentine drivebelts are usually tensioned by
an automatic tensioner.
ShimThin spacer, commonly used to adjust
the clearance or relative positions between
two parts. For example, shims inserted into or
under bucket tappets control valve
clearances. Clearance is adjusted by
changing the thickness of the shim.
Slide hammerA special puller that screws
into or hooks onto a component such as a
shaft or bearing; a heavy sliding handle on the
shaft bottoms against the end of the shaft to
knock the component free.SprocketA tooth or projection on the
periphery of a wheel, shaped to engage with a
chain or drivebelt. Commonly used to refer to
the sprocket wheel itself.
Starter inhibitor switchOn vehicles with an
automatic transmission, a switch that
prevents starting if the vehicle is not in Neutral
or Park.
StrutSee MacPherson strut.
TTappetA cylindrical component which
transmits motion from the cam to the valve
stem, either directly or via a pushrod and
rocker arm. Also called a cam follower.
ThermostatA heat-controlled valve that
regulates the flow of coolant between the
cylinder block and the radiator, so maintaining
optimum engine operating temperature. A
thermostat is also used in some air cleaners in
which the temperature is regulated.
Thrust bearingThe bearing in the clutch
assembly that is moved in to the release
levers by clutch pedal action to disengage the
clutch. Also referred to as a release bearing.
Timing beltA toothed belt which drives the
camshaft. Serious engine damage may result
if it breaks in service.
Timing chainA chain which drives the
camshaft.
Toe-inThe amount the front wheels are
closer together at the front than at the rear. On
rear wheel drive vehicles, a slight amount of
toe-in is usually specified to keep the front
wheels running parallel on the road by
offsetting other forces that tend to spread the
wheels apart.
Toe-outThe amount the front wheels are
closer together at the rear than at the front. On
front wheel drive vehicles, a slight amount of
toe-out is usually specified.
ToolsFor full information on choosing and
using tools, refer to the Haynes Automotive
Tools Manual.
TracerA stripe of a second colour applied to
a wire insulator to distinguish that wire from
another one with the same colour insulator.
Tune-upA process of accurate and careful
adjustments and parts replacement to obtain
the best possible engine performance.TurbochargerA centrifugal device, driven by
exhaust gases, that pressurises the intake air.
Normally used to increase the power output
from a given engine displacement, but can
also be used primarily to reduce exhaust
emissions (as on VW’s “Umwelt” Diesel
engine).
UUniversal joint or U-jointA double-pivoted
connection for transmitting power from a
driving to a driven shaft through an angle. A
U-joint consists of two Y-shaped yokes and a
cross-shaped member called the spider.
VValveA device through which the flow of
liquid, gas, vacuum, or loose material in bulk
may be started, stopped, or regulated by a
movable part that opens, shuts, or partially
obstructs one or more ports or passageways.
A valve is also the movable part of such a
device.
Valve clearanceThe clearance between the
valve tip (the end of the valve stem) and the
rocker arm or tappet. The valve clearance is
measured when the valve is closed.
Vernier caliperA precision measuring
instrument that measures inside and outside
dimensions. Not quite as accurate as a
micrometer, but more convenient.
ViscosityThe thickness of a liquid or its
resistance to flow.
VoltA unit for expressing electrical
“pressure” in a circuit. One volt that will
produce a current of one ampere through a
resistance of one ohm.
WWeldingVarious processes used to join metal
items by heating the areas to be joined to a
molten state and fusing them together. For
more information refer to the Haynes
Automotive Welding Manual.
Wiring diagramA drawing portraying the
components and wires in a vehicle’s electrical
system, using standardised symbols. For
more information refer to the Haynes
Automotive Electrical and Electronic Systems
Manual.
Serpentine drivebelt

A
Accelerator cable - 3•12, 13•80
Accelerator control system - 13•75
Accelerator pump -3•7, 3•8, 3•11, 13•66
Acknowledgements - 0•4
Aerial -9•10
Air bags - 0•5
Air cleaner -3•4, 13•60, 13•69, 13•67,
13•75, 13•79
Air pressure switch - 13•70
Air temperature sensor - 13•76
Airflow meter - 13•67, 13•69, 13•80
Alternator -9•3, 13•58, 13•103, 13•104
Alternator fault -9•14
Anti-flooding device -3•8, 3•9, 3•10, 3•11,
13•64
Anti-knock sensor - 13•86, 13•90
Anti-roll bar - 13•111
Antifreeze - 0•6, 0•13, 2•1, 2•2
Antiskid system - 13•103
Armrest - 13•112
Asbestos - 0•5
Auxiliary shaft -1•29, 1•30, 13•51, 13•53
B
Battery -0•5, 9•2
Battery fault -9•14
Bleeding brakes -8•7
Bleeding clutch - 13•94
Bodywork- 12•1et seq, 13•111, REF•4
Bonnet - 12•3, 12•4
Boots -7•2, 10•2, 13•98
Brake fluid -0•13, 8•1, 13•110, 13•111
Braking system-8•1et seq, 13•100,
REF•1, REF•2, REF•3
Braking system fault finding -8•9
Breakerless ignition system - 13•85, 13•86
Bumpers - 12•4, 12•11, 13•113
Burning -0•5
C
Cables -3•12, 5•1, 8•9, 9•8, 13•80
Calipers -8•3, 13•101, 13•102Camshaft -1•19, 1•21, 1•24, 1•29, 1•32,
13•21, 13•30, 13•34, 13•41, 13•42
Capacities -0•6, 13•17
Carburettors -3•6 to 3•11, 13•62 to 13•66
Carpets - 12•2
Cassette player-9•10
Catalytic converter - 13•77
Central door locking -9•11, 13•109
Centre console - 12•9
Check control (warning module) system -
9•12, 9•13, 13•110, 13•111
Choke -3•11, 3•12
Cigar lighter -9•13, 13•109
Clock -9•13, 13•108
Clutch-5•1et seq, 13•83, 13•92, 13•94
Clutch fault finding -5•3
Clutch fluid -0•13
CO emissions (mixture) - REF•4
Coil -4•6, 13•86, 13•90, 13•91
Coil spring - 11•3, 11•4
Condenser -4•5
Connecting rods -1•12, 1•18, 1•22, 1•26,
1•30, 13•25, 13•26, 13•30, 13•35,
13•47, 13•48, 13•53
Console - 12•9
Constant velocity joint -0•13, 7•3, 13•98,
13•99
Contact breaker points -4•2, 4•3
Contents -0•2
Control panel - 13•108
Conversion factors -0•14
Coolant -0•6, 0•13, 2•1, 2•2, 13•69, 13•70,
13•110, 13•111
Coolant pump -2•4, 13•55, 13•58
Cooling and heating systems-2•1et seq,
13•54, 13•55
Cooling and heating systems fault finding -
2•8
Courtesy lamp -9•5, 9•8
Crankcase -1•17
Crankcase ventilation system -1•8
Crankshaft -1•18, 1•20, 1•30, 1•31, 13•44,
13•45, 13•52
Crossmember - 11•4
Crushing -0•5
CV joints -0•13, 7•3, 13•98, 13•99
Cylinder block -1•17Cylinder head -1•10, 1•16, 1•19, 1•22,
1•25, 1•28, 1•32, 13•19, 13•22, 13•30,
13•34, 13•43, 13•44, 13•53
D
Dents in bodywork - 12•2
Depressurisation (fuel system) - 13•75
Digiplex 2 ignition system - 13•90
Dim-dip system - 13•106
Dimensions -0•6, 13•17
Direction indicators -9•7
Discs -8•4, 13•101, 13•102
Distributor -4•3, 4•5, 13•86, 13•89, 13•90,
13•92
Doors -9•11, 12•5, 12•6, 12•7, 13•111,
13•112, 13•114, REF•2
Drivebelts -2•3, 13•58
Driveshaft
Driveshafts and hubs fault finding -7•6
Driveshafts,hubs,roadwheels and tyres-
0•13, 7•1et seq, 10•4, 11•3, 11•6,
13•98, 13•99, REF•3, REF•4
Drums -8•4
Dwell angle -4•4
E
Economy gauge (Econometer) -3•11, 9•12
Electric shock -0•5
Electric windows -9•11, 13•109
Electrical control circuit (ECU) - 13•67,
13•71, 13•81, 13•86, 13•90
Electrical system-9•1et seq,13•103,
REF•2
Electrical system fault finding -9•14,
REF•9
Electronic ignition -4•3, 4•6, 4•7
Engine-1•1et seq, 13•19, 13•33, 13•37
Engine fault finding -1•35, 1•36, 2•8, 3•13,
4•9, 13•92, REF•10, REF•11
Engine oil -0•6, 0•13, 1•3, 1•4, 1•8
Engine speed sensor -4•7, 13•89, 13•91
Environmental considerations - REF•8
Exhaust emission checks - REF•4
Exhaust manifold - 13•77
Exhaust system -3•12, REF•3
IndexREF•17
REF
Note: References throughout this index relate to Chapter•page number

F
Facia - 12•10, 13•107
Fan -2•3, 13•57, 13•71, 13•84
Fast idle adjustment -3•7, 3•9, 3•10, 3•11,
13•64
Fault finding- REF`•9et seq
Fault finding - braking system -8•9
Fault finding - clutch -5•3
Fault finding - cooling and heating systems
-2•8
Fault finding - driveshafts and hubs -7•6
Fault finding - Econometer -9•12
Fault finding - electrical system -9•14,
REF•9
Fault finding - engine -1•35, 1•36, 2•8,
3•13, 4•9, 13•92, REF•10, REF•11
Fault finding - fuel system -3•9, 3•13,
13•84
Fault finding - ignition system -4•9,
REF•11
Fault finding - Microplex ignition system -
13•92
Fault finding - steering - 10•4
Fault finding - suspension - 11•6
Fault finding - transmission -6•4
Fault finding - turbocharger system - 13•84
Filling - 12•3
Final drive output shafts - 13•94
Fire -0•5
Float adjustment -3•7, 3•8, 3•10, 3•11,
13•64, 13•66
Flywheel -1•19, 1•21, 1•31, 13•46, 13•53
Fog lamps - 13•106
Fuel evaporation control system - 13•78
Fuel filter - 13•67, 13•72, 13•74, 13•79
Fuel gauge fault -9•14
Fuel injection electronic control unit (ECU)
- 13•77
Fuel injection system - 13•68, 13•69
Fuel injection system fault finding - 13•84
Fuel injectors - 13•69, 13•70, 13•71, 13•76,
13•77, 13•81, 13•84
Fuel level transmitter -3•5
Fuel pressure regulator - 13•70
Fuel pump -3•5, 13•61, 13•69, 13•72,
13•76, 13•80, 13•81
Fuel rail - 13•70, 13•81
Fuel system-3•1et seq, 13•60, REF•4
Fuel system fault finding -3•9, 3•13
Fuel tank -3•5, 13•61, 13•72
Fume or gas intoxication -0•5
Fuses -9•5, 13•105
G
Gaiters -7•2, 10•2, 13•98
Gashes in bodywork - 12•2
Gaskets -1•20
Gearbox - SeeTransmission
Gearchange lever -6•2
Gearchange linkage - 13•94, 13•95
Glossary of technical terms- REF•13et seq
Grille - 12•3, 13•113
H
Handbrake -8•8, 8•9, REF•1
Handles - 12•11
HC emissions - REF•4
Headlamp -9•6, 9•7, 13•105, 13•106
Heated tailgate window -9•10
Heater -2•5, 2•6, 13•58, 13•59, 13•108
Heater fault -2•8
Horn -9•6, 13•106
Horn fault -9•14
HT leads - 13•92
Hubs -7•3, 7•4, 11•3
Hydraulic hoses and pipes -8•6
Hydraulic system -8•7
Hydrofluoric acid -0•5
I
Idle speed adjustment -3•7, 13•62, 13•65,
13•68, 13•75, 13•79
Idling fault -1•36, 3•13, 13•84
Ignition coil - 13•86, 13•90, 13•91
Ignition switch -4•8
Ignition system-4•1et seq, 13•85
Ignition system fault finding -4•9, 9•14,
REF•11
Ignition unit - 13•89
Indicators -9•7
Injectors - 13•69, 13•70, 13•71, 13•76,
13•77, 13•81, 13•84
Inlet manifold - 13•70, 13•77, 13•80
Instrument panel -9•8, 13•107
Intercooler - 13•84
Interior lamps -9•5, 9•8
Introduction to the Fiat Uno -0•4
J
Jacking -0•8
Joint mating faces and gaskets - REF•8
Jump starting -0•7
L
Lambda sensor - 13•82
Lamps -9•6, 9•7, 9•8
Leaks -0•9, 1•36, 13•84
LED (light emitter diode) -9•12
Lights fault -9•14
Locknuts,locktabs and washers - REF•8
Locks -9•11, 10•4, 12•4, 12•6, 12•7,
13•109
Loudspeakers -9•11
Lubricants and fluids -0•13
M
Magnetic impulse generator winding -
13•86
Main bearings -1•20, 1•30, 13•52
Maintenance -0•10, 13•18
Manifolds -3•12, 13•70, 13•77, 13•80
Master cylinder -8•5, 13•103, 13•93
Microplex ignition system - 13•86, 13•89Microplex ignition system fault finding -
13•92
Mirrors - 12•11, 13•111, REF•1
Misfire -1•35, 4•9, REF•11
Mixture adjustment -3•7, 13•62, 13•65,
13•68, 13•75, 13•79
MOT test checks- REF•1et seq
Mountings -1•13, 1•27, 13•26, 13•35,
13•49
N
Needle valve - 13•66
Number plate lamp -9•7
O
Oil cooler - 13•36
Oil filter -1•8
Oil level sensor - 13•110, 13•111
Oil pressure fault -1•36, REF•11
Oil pump -1•13, 1•19, 1•22, 1•26, 1•29,
13•24, 13•30, 13•35, 13•46, 13•53
Oil seals -1•20, 13•41, 13•44, 13•45,
13•94, REF•8
Oil,engine -0•6, 0•13, 1•3, 1•4, 1•8
Oil,transmission -0•6, 0•13, 6•1, 13•14,
13•95
Overheating -2•8, 4•9, REF•11
P
Pad wear sensor - 13•110
Pads -8•2, 13•100, 13•101
Parking lamp -9•7
Pedals -5•2, 8•9, 13•92, 13•102
Pinking -1•36, 13•84, REF•11
Pistons -1•12, 1•18, 1•22, 1•26, 1•30,
13•25, 13•26, 13•30, 13•35, 13•47,
13•48, 13•53
Plastic components - 13•111
Points -4•2, 4•3
Poisonous or irritant substances -0•5
Power module - 13•90
Pre-ignition -1•36, 13•84, REF•11
Pressure regulating valve -8•6, 13•102
Pressure sensor - 13•86
R
Radiator -2•3, 12•3, 13•57, 13•113
Radio -9•10, 13•110
Rear lamp cluster -9•7
Regulator (voltage) -9•4
Regulator (window) - 12•7
Relays -9•5, 13•71, 13•105
Repair procedures - REF•8
Respraying - 12•3
Rocker cover - 13•19
Rockers -1•19
Roof rack - 12•11
Routine maintenance -0•10, 13•18
Rust holes in bodywork - 12•2
REF•18Index