trip computer FIAT UNO 1983 Service Repair Manual

4 Engine-
903 and 1299/1301 cc
Sump pan sealing strips (903 cc
engine) - modification
1The design of the sealing strips which go
between the sump pan and the main bearing
caps has been changed. Make sure that the
narrower side of the strip fits into the channel
in the sump pan.
1299 cc engine - description
2In April 1984, a 1299 cc engine was
introduced, progressively replacing the
1301 cc units used previously. The new
engine is identical to the 1301 cc engine
described in Chapter 1, with the exception of
having a slightly shorter stroke.
3However, as of approximately September
1987, the 1299 cc unit was phased out, being
progressively replaced by the 1301 cc engine
used initially.
4As mentioned above, the two engines are
all but identical, so identification of the unit
fitted should not be necessary in practice.
Consult a FIAT dealer if in doubt.
Rocker cover (903 cc engine) -
removal
5Before removing the rocker cover, it will be
necessary to remove the distributor, first.
Refer to Chapter 4 for more details.
Cylinder head (903 cc engine) -
refitting
6Modified cylinder head bolts are fitted to
903 cc models, from engine number 8581470.
When refitting the cylinder head, tighten each
head bolt, as described in Chapter 1, by the
torques and angles shown the Specifications
in this Chapter.
5 Engine-
999 and 1108 cc (FIRE)
Note:Later models are fitted with SPi fuel
injection. Where a procedure refers to a
carburettor, if applicable, replace with throttle
body.
PART A: GENERAL
Description
1Both of these engine types are designated
FIRE (Fully Integrated Robotised Engine),
being largely manufactured and assembled by
computer-controlled mechanical robots.
2The engine is of oversquare design, having
four cylinders and a belt-driven overhead
camshaft.
3The high torque of this engine enableshigher gear ratios to be used with the result
that fuel economy is exceptionally good.
4The cylinder head is of light alloy, while the
cylinder block is cast-iron.
5The camshaft is supported in three
bearings which have detachable caps.
6Valve clearances are maintained by shims
located in the cam followers (tappets).
7The cylinder head is of crossflow type
having the intake manifold (coolant-heated)
and exhaust manifold on opposite sides.
8The pistons have two compression rings
and one oil control ring and are connected to
the connecting rods by means of a gudgeon
pin which is an interference fit in the rod
small-end.
9The crankshaft is supported in five main
bearings. The upper section of the centre
bearing shell retains semi-circular thrust
washers to control crankshaft endfloat.
10The oil pump, which is of gear type, is
Supplement: Revisions and information on later models 13•19
Fig. 13.2 Cross-section view of the 999 and 1108 cc engine (Sec 5A)
Fig. 13.1 Correct method of fitting sump
pan sealing strip (Sec 4)
13

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