check engine FIAT UNO 1983 Service Repair Manual

MOT Test ChecksREF•3
REF
Exhaust system
MStart the engine. With your assistant
holding a rag over the tailpipe, check the
entire system for leaks. Repair or renew
leaking sections.
Jack up the front and rear of the vehicle,
and securely support it on axle stands.
Position the stands clear of the suspension
assemblies. Ensure that the wheels are
clear of the ground and that the steering
can be turned from lock to lock.
Steering mechanism
MHave your assistant turn the steering from
lock to lock. Check that the steering turns
smoothly, and that no part of the steering
mechanism, including a wheel or tyre, fouls
any brake hose or pipe or any part of the body
structure.
MExamine the steering rack rubber gaiters
for damage or insecurity of the retaining clips.
If power steering is fitted, check for signs of
damage or leakage of the fluid hoses, pipes or
connections. Also check for excessive
stiffness or binding of the steering, a missing
split pin or locking device, or severe corrosion
of the body structure within 30 cm of any
steering component attachment point.
Front and rear suspension and
wheel bearings
MStarting at the front right-hand side, grasp
the roadwheel at the 3 o’clock and 9 o’clock
positions and shake it vigorously. Check for
free play or insecurity at the wheel bearings,
suspension balljoints, or suspension mount-
ings, pivots and attachments.
MNow grasp the wheel at the 12 o’clock and
6 o’clock positions and repeat the previous
inspection. Spin the wheel, and check for
roughness or tightness of the front wheel
bearing.
MIf excess free play is suspected at a
component pivot point, this can be confirmed
by using a large screwdriver or similar tool and
levering between the mounting and the
component attachment. This will confirm
whether the wear is in the pivot bush, its
retaining bolt, or in the mounting itself (the bolt
holes can often become elongated).
MCarry out all the above checks at the other
front wheel, and then at both rear wheels.
Springs and shock absorbers
MExamine the suspension struts (when
applicable) for serious fluid leakage, corrosion,
or damage to the casing. Also check the
security of the mounting points.
MIf coil springs are fitted, check that the
spring ends locate in their seats, and that the
spring is not corroded, cracked or broken.
MIf leaf springs are fitted, check that all
leaves are intact, that the axle is securely
attached to each spring, and that there is no
deterioration of the spring eye mountings,
bushes, and shackles.MThe same general checks apply to vehicles
fitted with other suspension types, such as
torsion bars, hydraulic displacer units, etc.
Ensure that all mountings and attachments are
secure, that there are no signs of excessive
wear, corrosion or damage, and (on hydraulic
types) that there are no fluid leaks or damaged
pipes.
MInspect the shock absorbers for signs of
serious fluid leakage. Check for wear of the
mounting bushes or attachments, or damage
to the body of the unit.
Driveshafts
(fwd vehicles only)
MRotate each front wheel in turn and inspect
the constant velocity joint gaiters for splits or
damage. Also check that each driveshaft is
straight and undamaged.
Braking system
MIf possible without dismantling, check
brake pad wear and disc condition. Ensure
that the friction lining material has not worn
excessively, (A) and that the discs are not
fractured, pitted, scored or badly worn (B).
MExamine all the rigid brake pipes
underneath the vehicle, and the flexible
hose(s) at the rear. Look for corrosion, chafing
or insecurity of the pipes, and for signs of
bulging under pressure, chafing, splits or
deterioration of the flexible hoses.
MLook for signs of fluid leaks at the brake
calipers or on the brake backplates. Repair or
renew leaking components.
MSlowly spin each wheel, while your
assistant depresses and releases the
footbrake. Ensure that each brake is operating
and does not bind when the pedal is released.
3Checks carried out
WITH THE VEHICLE RAISED
AND THE WHEELS FREE TO
TURN

REF•4MOT Test Checks
MExamine the handbrake mechanism,
checking for frayed or broken cables,
excessive corrosion, or wear or insecurity of
the linkage. Check that the mechanism works
on each relevant wheel, and releases fully,
without binding.
MIt is not possible to test brake efficiency
without special equipment, but a road test can
be carried out later to check that the vehicle
pulls up in a straight line.
Fuel and exhaust systems
MInspect the fuel tank (including the filler
cap), fuel pipes, hoses and unions. All
components must be secure and free from
leaks.
MExamine the exhaust system over its entire
length, checking for any damaged, broken or
missing mountings, security of the retaining
clamps and rust or corrosion.
Wheels and tyres
MExamine the sidewalls and tread area of
each tyre in turn. Check for cuts, tears, lumps,
bulges, separation of the tread, and exposure
of the ply or cord due to wear or damage.
Check that the tyre bead is correctly seated
on the wheel rim, that the valve is sound andproperly seated, and that the wheel is not
distorted or damaged.
MCheck that the tyres are of the correct size
for the vehicle, that they are of the same size
and type on each axle, and that the pressures
are correct.
MCheck the tyre tread depth. The legal
minimum at the time of writing is 1.6 mm over
at least three-quarters of the tread width.
Abnormal tread wear may indicate incorrect
front wheel alignment.
Body corrosion
MCheck the condition of the entire vehicle
structure for signs of corrosion in load-bearing
areas. (These include chassis box sections,
side sills, cross-members, pillars, and all
suspension, steering, braking system and
seat belt mountings and anchorages.) Any
corrosion which has seriously reduced the
thickness of a load-bearing area is likely to
cause the vehicle to fail. In this case
professional repairs are likely to be needed.
MDamage or corrosion which causes sharp
or otherwise dangerous edges to be exposed
will also cause the vehicle to fail.
Petrol models
MHave the engine at normal operating
temperature, and make sure that it is in good
tune (ignition system in good order, air filter
element clean, etc).
MBefore any measurements are carried out,
raise the engine speed to around 2500 rpm,
and hold it at this speed for 20 seconds. Allowthe engine speed to return to idle, and watch
for smoke emissions from the exhaust
tailpipe. If the idle speed is obviously much
too high, or if dense blue or clearly-visible
black smoke comes from the tailpipe for more
than 5 seconds, the vehicle will fail. As a rule
of thumb, blue smoke signifies oil being burnt
(engine wear) while black smoke signifies
unburnt fuel (dirty air cleaner element, or other
carburettor or fuel system fault).
MAn exhaust gas analyser capable of
measuring carbon monoxide (CO) and
hydrocarbons (HC) is now needed. If such an
instrument cannot be hired or borrowed, a
local garage may agree to perform the check
for a small fee.
CO emissions (mixture)
MAt the time of writing, the maximum CO
level at idle is 3.5% for vehicles first used after
August 1986 and 4.5% for older vehicles.
From January 1996 a much tighter limit
(around 0.5%) applies to catalyst-equipped
vehicles first used from August 1992. If the
CO level cannot be reduced far enough to
pass the test (and the fuel and ignition
systems are otherwise in good condition) then
the carburettor is badly worn, or there is some
problem in the fuel injection system or
catalytic converter (as applicable).
HC emissionsMWith the CO emissions within limits, HC
emissions must be no more than 1200 ppm
(parts per million). If the vehicle fails this test
at idle, it can be re-tested at around 2000 rpm;
if the HC level is then 1200 ppm or less, this
counts as a pass.
MExcessive HC emissions can be caused by
oil being burnt, but they are more likely to be
due to unburnt fuel.
Diesel models
MThe only emission test applicable to Diesel
engines is the measuring of exhaust smoke
density. The test involves accelerating the
engine several times to its maximum
unloaded speed.
Note: It is of the utmost importance that the
engine timing belt is in good condition before
the test is carried out.
M
Excessive smoke can be caused by a dirty
air cleaner element. Otherwise, professional
advice may be needed to find the cause.
4Checks carried out on
YOUR VEHICLE’S EXHAUST
EMISSION SYSTEM

REF•8General Repair Procedures
Whenever servicing, repair or overhaul work
is carried out on the car or its components,
observe the following procedures and
instructions. This will assist in carrying out the
operation efficiently and to a professional
standard of workmanship.
Joint mating faces and gaskets
When separating components at their
mating faces, never insert screwdrivers or
similar implements into the joint between the
faces in order to prise them apart. This can
cause severe damage which results in oil
leaks, coolant leaks, etc upon reassembly.
Separation is usually achieved by tapping
along the joint with a soft-faced hammer in
order to break the seal. However, note that
this method may not be suitable where
dowels are used for component location.
Where a gasket is used between the mating
faces of two components, a new one must be
fitted on reassembly; fit it dry unless otherwise
stated in the repair procedure. Make sure that
the mating faces are clean and dry, with all
traces of old gasket removed. When cleaning a
joint face, use a tool which is unlikely to score
or damage the face, and remove any burrs or
nicks with an oilstone or fine file.
Make sure that tapped holes are cleaned
with a pipe cleaner, and keep them free of
jointing compound, if this is being used,
unless specifically instructed otherwise.
Ensure that all orifices, channels or pipes
are clear, and blow through them, preferably
using compressed air.
Oil seals
Oil seals can be removed by levering them
out with a wide flat-bladed screwdriver or
similar implement. Alternatively, a number of
self-tapping screws may be screwed into the
seal, and these used as a purchase for pliers or
some similar device in order to pull the seal free.
Whenever an oil seal is removed from its
working location, either individually or as part
of an assembly, it should be renewed.
The very fine sealing lip of the seal is easily
damaged, and will not seal if the surface it
contacts is not completely clean and free from
scratches, nicks or grooves. If the original
sealing surface of the component cannot be
restored, and the manufacturer has not made
provision for slight relocation of the seal
relative to the sealing surface, the component
should be renewed.
Protect the lips of the seal from any surface
which may damage them in the course of
fitting. Use tape or a conical sleeve where
possible. Lubricate the seal lips with oil before
fitting and, on dual-lipped seals, fill the space
between the lips with grease.
Unless otherwise stated, oil seals must be
fitted with their sealing lips toward the
lubricant to be sealed.
Use a tubular drift or block of wood of the
appropriate size to install the seal and, if the
seal housing is shouldered, drive the seal
down to the shoulder. If the seal housing isunshouldered, the seal should be fitted with
its face flush with the housing top face (unless
otherwise instructed).
Screw threads and fastenings
Seized nuts, bolts and screws are quite a
common occurrence where corrosion has set
in, and the use of penetrating oil or releasing
fluid will often overcome this problem if the
offending item is soaked for a while before
attempting to release it. The use of an impact
driver may also provide a means of releasing
such stubborn fastening devices, when used
in conjunction with the appropriate
screwdriver bit or socket. If none of these
methods works, it may be necessary to resort
to the careful application of heat, or the use of
a hacksaw or nut splitter device.
Studs are usually removed by locking two
nuts together on the threaded part, and then
using a spanner on the lower nut to unscrew
the stud. Studs or bolts which have broken off
below the surface of the component in which
they are mounted can sometimes be removed
using a stud extractor. Always ensure that a
blind tapped hole is completely free from oil,
grease, water or other fluid before installing
the bolt or stud. Failure to do this could cause
the housing to crack due to the hydraulic
action of the bolt or stud as it is screwed in.
When tightening a castellated nut to accept
a split pin, tighten the nut to the specified
torque, where applicable, and then tighten
further to the next split pin hole. Never slacken
the nut to align the split pin hole, unless stated
in the repair procedure.
When checking or retightening a nut or bolt
to a specified torque setting, slacken the nut
or bolt by a quarter of a turn, and then
retighten to the specified setting. However,
this should not be attempted where angular
tightening has been used.
For some screw fastenings, notably
cylinder head bolts or nuts, torque wrench
settings are no longer specified for the latter
stages of tightening, “angle-tightening” being
called up instead. Typically, a fairly low torque
wrench setting will be applied to the
bolts/nuts in the correct sequence, followed
by one or more stages of tightening through
specified angles.
Locknuts, locktabs and washers
Any fastening which will rotate against a
component or housing during tightening
should always have a washer between it and
the relevant component or housing.
Spring or split washers should always be
renewed when they are used to lock a critical
component such as a big-end bearing
retaining bolt or nut. Locktabs which are
folded over to retain a nut or bolt should
always be renewed.
Self-locking nuts can be re-used in non-
critical areas, providing resistance can be felt
when the locking portion passes over the bolt
or stud thread. However, it should be noted
that self-locking stiffnuts tend to lose theireffectiveness after long periods of use, and
should then be renewed as a matter of course.
Split pins must always be replaced with
new ones of the correct size for the hole.
When thread-locking compound is found
on the threads of a fastener which is to be re-
used, it should be cleaned off with a wire
brush and solvent, and fresh compound
applied on reassembly.
Special tools
Some repair procedures in this manual
entail the use of special tools such as a press,
two or three-legged pullers, spring com-
pressors, etc. Wherever possible, suitable
readily-available alternatives to the manu-
facturer’s special tools are described, and are
shown in use. In some instances, where no
alternative is possible, it has been necessary
to resort to the use of a manufacturer’s tool,
and this has been done for reasons of safety
as well as the efficient completion of the repair
operation. Unless you are highly-skilled and
have a thorough understanding of the
procedures described, never attempt to
bypass the use of any special tool when the
procedure described specifies its use. Not
only is there a very great risk of personal
injury, but expensive damage could be
caused to the components involved.
Environmental considerations
When disposing of used engine oil, brake
fluid, antifreeze, etc, give due consideration to
any detrimental environmental effects. Do not,
for instance, pour any of the above liquids
down drains into the general sewage system,
or onto the ground to soak away. Many local
council refuse tips provide a facility for waste
oil disposal, as do some garages. If none of
these facilities are available, consult your local
Environmental Health Department, or the
National Rivers Authority, for further advice.
With the universal tightening-up of legis-
lation regarding the emission of environmen-
tally-harmful substances from motor vehicles,
most vehicles have tamperproof devices fitted
to the main adjustment points of the fuel
system. These devices are primarily designed
to prevent unqualified persons from adjusting
the fuel/air mixture, with the chance of a
consequent increase in toxic emissions. If
such devices are found during servicing or
overhaul, they should, wherever possible, be
renewed or refitted in accordance with the
manufacturer’s requirements or current
legislation.
Note: It is
antisocial and
illegal to dump
oil down the
drain. To find
the location of
your local oil
recycling
bank, call this
number free.

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!

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•14Glossary of Technical Terms
Catalytic converterA silencer-like device in
the exhaust system which converts certain
pollutants in the exhaust gases into less
harmful substances.
CirclipA ring-shaped clip used to prevent
endwise movement of cylindrical parts and
shafts. An internal circlip is installed in a
groove in a housing; an external circlip fits into
a groove on the outside of a cylindrical piece
such as a shaft.
ClearanceThe amount of space between
two parts. For example, between a piston and
a cylinder, between a bearing and a journal,
etc.
Coil springA spiral of elastic steel found in
various sizes throughout a vehicle, for
example as a springing medium in the
suspension and in the valve train.
CompressionReduction in volume, and
increase in pressure and temperature, of a
gas, caused by squeezing it into a smaller
space.
Compression ratioThe relationship between
cylinder volume when the piston is at top
dead centre and cylinder volume when the
piston is at bottom dead centre.
Constant velocity (CV) jointA type of
universal joint that cancels out vibrations
caused by driving power being transmitted
through an angle.
Core plugA disc or cup-shaped metal device
inserted in a hole in a casting through which
core was removed when the casting was
formed. Also known as a freeze plug or
expansion plug.
CrankcaseThe lower part of the engine
block in which the crankshaft rotates.
CrankshaftThe main rotating member, or
shaft, running the length of the crankcase,
with offset “throws” to which the connecting
rods are attached.
Crocodile clipSee Alligator clipDDiagnostic codeCode numbers obtained by
accessing the diagnostic mode of an engine
management computer. This code can be
used to determine the area in the system
where a malfunction may be located.
Disc brakeA brake design incorporating a
rotating disc onto which brake pads are
squeezed. The resulting friction converts the
energy of a moving vehicle into heat.
Double-overhead cam (DOHC)An engine
that uses two overhead camshafts, usually
one for the intake valves and one for the
exhaust valves.
Drivebelt(s)The belt(s) used to drive
accessories such as the alternator, water
pump, power steering pump, air conditioning
compressor, etc. off the crankshaft pulley.
DriveshaftAny shaft used to transmit
motion. Commonly used when referring to the
axleshafts on a front wheel drive vehicle.
Drum brakeA type of brake using a drum-
shaped metal cylinder attached to the inner
surface of the wheel. When the brake pedal is
pressed, curved brake shoes with friction
linings press against the inside of the drum to
slow or stop the vehicle.
EEGR valveA valve used to introduce exhaust
gases into the intake air stream.
Electronic control unit (ECU)A computer
which controls (for instance) ignition and fuel
injection systems, or an anti-lock braking
system. For more information refer to the
Haynes Automotive Electrical and Electronic
Systems Manual.
Electronic Fuel Injection (EFI)A computer
controlled fuel system that distributes fuel
through an injector located in each intake port
of the engine.
Emergency brakeA braking system,
independent of the main hydraulic system,
that can be used to slow or stop the vehicle if
the primary brakes fail, or to hold the vehicle
stationary even though the brake pedal isn’t
depressed. It usually consists of a hand lever
that actuates either front or rear brakes
mechanically through a series of cables and
linkages. Also known as a handbrake or
parking brake.EndfloatThe amount of lengthwise
movement between two parts. As applied to a
crankshaft, the distance that the crankshaft
can move forward and back in the cylinder
block.
Engine management system (EMS)A
computer controlled system which manages
the fuel injection and the ignition systems in
an integrated fashion.
Exhaust manifoldA part with several
passages through which exhaust gases leave
the engine combustion chambers and enter
the exhaust pipe.
F
Fan clutchA viscous (fluid) drive coupling
device which permits variable engine fan
speeds in relation to engine speeds.
Feeler bladeA thin strip or blade of hardened
steel, ground to an exact thickness, used to
check or measure clearances between parts.
Firing orderThe order in which the engine
cylinders fire, or deliver their power strokes,
beginning with the number one cylinder.
Flywheel A heavy spinning wheel in which
energy is absorbed and stored by means of
momentum. On cars, the flywheel is attached
to the crankshaft to smooth out firing
impulses.
Free playThe amount of travel before any
action takes place. The “looseness” in a
linkage, or an assembly of parts, between the
initial application of force and actual
movement. For example, the distance the
brake pedal moves before the pistons in the
master cylinder are actuated.
FuseAn electrical device which protects a
circuit against accidental overload. The typical
fuse contains a soft piece of metal which is
calibrated to melt at a predetermined current
flow (expressed as amps) and break the
circuit.
Fusible linkA circuit protection device
consisting of a conductor surrounded by
heat-resistant insulation. The conductor is
smaller than the wire it protects, so it acts as
the weakest link in the circuit. Unlike a blown
fuse, a failed fusible link must frequently be
cut from the wire for replacement.Catalytic converter
Crankshaft assembly
Accessory drivebelts
Feeler blade

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