maintenance FIAT UNO 1983 Service Service Manual

Tools and Working FacilitiesREF•7
REF
MImpact screwdriver
MMicrometer and/or vernier calipers (see
illustrations)
MDial gauge (see illustration)
MUniversal electrical multi-meter
MCylinder compression gauge
(see illustration)
MClutch plate alignment set (see
illustration)
MBrake shoe steady spring cup removal tool
(see illustration)
MBush and bearing removal/installation set
(see illustration)
MStud extractors (see illustration)
MTap and die set (see illustration)
MLifting tackle
MTrolley jack
Buying tools
For practically all tools, a tool factor is the
best source, since he will have a very
comprehensive range compared with the
average garage or accessory shop. Having
said that, accessory shops often offer
excellent quality tools at discount prices, so it
pays to shop around.
Remember, you don’t have to buy the most
expensive items on the shelf, but it is always
advisable to steer clear of the very cheap
tools. There are plenty of good tools around atreasonable prices, but always aim to
purchase items which meet the relevant
national safety standards. If in doubt, ask the
proprietor or manager of the shop for advice
before making a purchase.
Care and maintenance of tools
Having purchased a reasonable tool kit, it is
necessary to keep the tools in a clean and
serviceable condition. After use, always wipe
off any dirt, grease and metal particles using a
clean, dry cloth, before putting the tools away.
Never leave them lying around after they have
been used. A simple tool rack on the garage
or workshop wall for items such as
screwdrivers and pliers is a good idea. Store
all normal spanners and sockets in a metal
box. Any measuring instruments, gauges,
meters, etc, must be carefully stored where
they cannot be damaged or become rusty.
Take a little care when tools are used.
Hammer heads inevitably become marked,
and screwdrivers lose the keen edge on their
blades from time to time. A little timely
attention with emery cloth or a file will soon
restore items like this to a good serviceable
finish.
Working facilities
Not to be forgotten when discussing toolsis the workshop itself. If anything more than
routine maintenance is to be carried out,
some form of suitable working area becomes
essential.
It is appreciated that many an owner-
mechanic is forced by circumstances to
remove an engine or similar item without the
benefit of a garage or workshop. Having done
this, any repairs should always be done under
the cover of a roof.
Wherever possible, any dismantling should
be done on a clean, flat workbench or table at
a suitable working height.
Any workbench needs a vice; one with a
jaw opening of 100 mm is suitable for most
jobs. As mentioned previously, some clean
dry storage space is also required for tools, as
well as for any lubricants, cleaning fluids,
touch-up paints and so on, which become
necessary.
Another item which may be required, and
which has a much more general usage, is an
electric drill with a chuck capacity of at least 8
mm. This, together with a good range of twist
drills, is virtually essential for fitting
accessories.
Last, but not least, always keep a supply of
old newspapers and clean, lint-free rags
available, and try to keep any working area as
clean as possible.
Bush and bearing removal/installation setStud extractor setTap and die set

Fault FindingREF•9
REF
Introduction
The vehicle owner who does his or her own
maintenance according to the recommended
schedules should not have to use this section
of the manual very often. Modern component
reliability is such that, provided those items
subject to wear or deterioration are inspected
or renewed at the specified intervals, sudden
failure is comparatively rare. Faults do not
usually just happen as a result of sudden
failure, but develop over a period of time.
Major mechanical failures in particular are
usually preceded by characteristic symptoms
over hundreds or even thousands of miles.
Those components which do occasionally fail
without warning are often small and easily
carried in the vehicle.
With any fault finding, the first step is to
decide where to begin investigations.
Sometimes this is obvious, but on other
occasions a little detective work will be
necessary. The owner who makes half a
dozen haphazard adjustments or
replacements may be successful in curing a
fault (or its symptoms), but he will be none the
wiser if the fault recurs and he may well have
spent more time and money than was
necessary. A calm and logical approach will
be found to be more satisfactory in the long
run. Always take into account any warning
signs or abnormalities that may have been
noticed in the period preceding the fault –
power loss, high or low gauge readings,
unusual noises or smells, etc – and remember
that failure of components such as fuses or
spark plugs may only be pointers to some
underlying fault.
The pages which follow here are intended
to help in cases of failure to start or
breakdown on the road. There is also a Fault
Diagnosis Section at the end of each Chapter
which should be consulted if the preliminary
checks prove unfruitful. Whatever the fault,
certain basic principles apply. These are as
follows:Verify the fault. This is simply a matter of
being sure that you know what the symptoms
are before starting work. This is particularly
important if you are investigating a fault for
someone else who may not have described it
very accurately.
Don’t overlook the obvious. For example,
if the vehicle won’t start, is there petrol in the
tank? (Don’t take anyone else’s word on this
particular point, and don’t trust the fuel gauge
either!) If an electrical fault is indicated, look
for loose or broken wires before digging out
the test gear.
Cure the disease, not the symptom.
Substituting a flat battery with a fully charged
one will get you off the hard shoulder, but if
the underlying cause is not attended to,the
new battery will go the same way. Similarly,
changing oil-fouled spark plugs for a new set
will get you moving again, but remember that
the reason for the fouling (if it wasn’t simply an
incorrect grade of plug) will have to be
established and corrected.
Don’t take anything for granted.
Particularly, don’t forget that a ‘new’
component may itself be defective (especially
if it’s been rattling round in the boot for
months), and don’t leave components out of a
fault diagnosis sequence just because they
are new or recently fitted. When you do finally
diagnose a difficult fault, you’ll probably
realise that all the evidence was there from
the start.
Electrical faults
Electrical faults can be more puzzling than
straightforward mechanical failures, but they
are no less susceptible to logical analysis if
the basic principles of operation are
understood. Vehicle electrical wiring exists in
extremely unfavourable conditions – heat,
vibration and chemical attack and the first
things to look for are loose or corroded
connections and broken or chafed wires,especially where the wires pass through holes
in the bodywork or are subject to vibration.
All metal-bodied vehicles in current
production have one pole of the battery
‘earthed’, ie connected to the vehicle
bodywork, and in nearly all modern vehicles it
is the negative (–) terminal. The various
electrical components – motors, bulb holders,
etc – are also connected to earth, either by
means of a lead or directly by their mountings.
Electric current flows through the component
and then back to the battery via the
bodywork. If the component mounting is
loose or corroded, or if a good path back to
the battery is not available, the circuit will be
incomplete and malfunction will result. The
engine and/or gearbox are also earthed by
means of flexible metal straps to the body or
subframe; if these straps are loose or missing,
starter motor, generator and ignition trouble
may result.
Assuming the earth return to be
satisfactory, electrical faults will be due either
to component malfunction or to defects in the
current supply. Individual components are
dealt with in Chapter 9. If supply wires are
broken or cracked internally this results in an
open-circuit, and the easiest way to check for
this is to bypass the suspect wire temporarily
with a length of wire having a crocodile clip or
suitable connector at each end. Alternatively,
a 12V test lamp can be used to verify the
presence of supply voltage at various points
along the wire and the break can be thus
isolated.
If a bare portion of a live wire touches the
bodywork or other earthed metal part, the
electricity will take the low-resistance path
thus formed back to the battery: this is known
as a short-circuit. Hopefully a short-circuit will
blow a fuse, but otherwise it may cause
burning of the insulation (and possibly further
short-circuits) or even a fire. This is why it is
inadvisable to bypass persistently blowing
fuses with silver foil or wire.

Engine fails to turn when starter
operated
m mFlat battery (recharge use jump leads or
push start)
m mBattery terminals loose or corroded
m mBattery earth to body defective
m mEngine earth strap loose or broken
m mStarter motor (or solenoid) wiring loose or
broken
m mIgnition/starter switch faulty
m mMajor mechanical failure (seizure)
m mStarter or solenoid internal fault (see
Chapter 12)
Starter motor turns engine slowly
m mPartially discharged battery (recharge, use
jump leads, or push start)
m mBattery terminals loose or corroded
m mBattery earth to body defective
m mEngine earth strap loose m mStarter motor (or solenoid) wiring loose
m mStarter motor internal fault (see Chapter 9)
Starter motor spins without
turning engine
m mFlywheel gear teeth damaged or worn
m mStarter motor mounting bolts loose
Engine turns normally but fails to
start
m mDamp or dirty HT leads and distributor cap
(crank engine and check for spark)
m mNo fuel in tank (check for delivery at
carburettor) m mExcessive choke (hot engine) or insufficient
choke (cold engine)
m mFouled or incorrectly gapped spark plugs
(remove, clean and regap)
m mOther ignition system fault (see Chapter 4)
m mOther fuel system fault (see Chapter 3)
m mPoor compression (see Chapter 1)
m mMajor mechanical failure (eg camshaft drive)
Engine fires but will not run
m
mInsufficient choke (cold engine)
m mAir leaks at carburettor or inlet manifold
m mFuel starvation (see Chapter 3)
m mIgnition fault (see Chapter 4)
Engine will not start
REF•10Fault Finding
Spares and tool kit
Most vehicles are supplied only with
sufficient tools for wheel changing; the
Maintenance and minor repairtool kit detailed
in Tools and working facilities,with the
addition of a hammer, is probably sufficient
for those repairs that most motorists would
consider attempting at the roadside. In
addition a few items which can be fitted
without too much trouble in the event of a
breakdown should be carried. Experience and
available space will modify the list below, but
the following may save having to call on
professional assistance:
m mSpark plugs, clean and correctly gapped
m mHT lead and plug cap – long enough to
reach the plug furthest from the distributor
m mDistributor rotor, condenser and contact
breaker points (where applicable)m mDrivebelt(s) — emergency type may
suffice
m mSpare fuses
m mSet of principal light bulbs
m mTin of radiator sealer and hose bandage
m mExhaust bandage
m mRoll of insulating tape
m mLength of soft iron wire
m mLength of electrical flex
m mTorch or inspection lamp (can double as
test lamp)
m mBattery jump leads
m mTow-rope
m mIgnition waterproofing aerosol
m mLitre of engine oil
m mSealed can of hydraulic fluid
m mEmergency windscreen
m mWormdrive clips
m mTube of filler pasteIf spare fuel is carried, a can designed for
the purpose should be used to minimise risks
of leakage and collision damage. A first aid kit
and a warning triangle, whilst not at present
compulsory in the UK, are obviously sensible
items to carry in addition to the above. When
touring abroad it may be advisable to carry
additional spares which, even if you cannot fit
them yourself, could save having to wait while
parts are obtained. The items below may be
worth considering:
m mClutch and throttle cables
m mCylinder head gasket
m mAlternator brushes
m mTyre valve core
One of the motoring organisations will be
able to advise on availability of fuel, etc, in
foreign countries.
A simple test lamp is useful for checking
electrical faultsCarrying a few spares may save you a long walk!

Buying spare parts
Spare parts are available from many
sources, for example, FIAT garages, other
garages and accessory shops, and motor
factors. Our advice regarding spare parts is as
follows:
Officially appointed FIAT garages -This is
the best source of parts which are peculiar to
your car and otherwise not generally available
(eg complete cylinder heads, internal gearbox
components, badges, interior trim etc). It is
also the only place at which you should buy
parts if your vehicle is still under warranty;
non-FlAT components may invalidate the
warranty. To be sure of obtaining the correct
parts it will always be necessary to give the
partsman your car’s engine number, chassis
number and number for spares, and if
possible, to take the old part along for positive
identification. Many parts are available under
a factory exchange scheme - any parts
returned should always be clean. It obviously
makes good sense to go straight to the
specialists on your car for this type of part for
they are best equipped to supply you. They
will also be able to provide their own FIATservice manual for your car should you require
one.
Other garages and accessory shops - These
are often very good places to buy material
and components needed for the maintenance
of your car (eg oil filters, spark plugs, bulbs,
drivebelts, oils and grease, touch-up paint,
filler paste etc). They also sell accessories,
usually have convenient opening hours,
charge lower prices and can often be found
not far from home.
Motor factors - Good factors stock all of the
more important components which wear out
relatively quickly (eg clutch components,
pistons, valves, exhaust systems, brake
pipes/seals/shoes and pads etc). Motor
factors will often provide new or reconditioned
components on a part exchange basis - this
can save a considerable amount of money.
Vehicle identification
numbers
Modifications are a continuing and
unpublicised process in vehicle manufacture
quite apart from major model changes. Spareparts manuals and lists are compiled upon a
numerical basis, the individual vehicle
numbers being essential to correct identifi-
cation of the component required.
The chassis type and number plate is
located on the wing valance under the bonnet.
The identification data plate is located on the
radiator top rail. The engine type and number
is stamped on the cylinder block. The
paintwork colour code is given on a label
stuck to the inner surface of the tailgate.
REF•12Buying spare parts & Vehicle identification numbers
Manufacturer’s plate legend
Location of under-bonnet identification numbers and plates
A Chassis type and number
B Manufacturer’s plate
C Engine number (903 cc)
D Engine number (1116 cc and 1301 cc)
Engine number on 1116 cc engine
A Name of manufacturer
B Approval number
C Vehicle identification number
D Chassis serial number
E Maximum laden weight
F Maximum laden weight
(vehicle plus trailer)G Maximum front axle weight
H Maximum rear axle weight
I Engine type
L Body type
M Spares reference
N Diesel models only (smoke
coefficient)

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