1983 FIAT UNO four wheel drive

Ignition unit
36This comprises four elements (photo).
a) Power module - receives the ignition
advance command and controls the
conduction angle of the primary current
and energy stored in the coil.
b) Dissipater plate - eliminates the heat
which is generated by the high volume of
current.
c) Ignition coil with low primary resistance.
d) Distributor - a means of distributing high
tension to the spark plugs. The rotor is
driven in an anti-clockwise direction
(viewed from transmission) by a dog on
the end of the camshaft.
37The system incorporates a safety
pressure switch, which cuts out the ignition if
the turbocharging pressure exceeds a value
of between 0.84 and 0.93 bars (12.2 and
13.5 lbf/in
2) above atmospheric pressure.
Distributor (Microplex) -
removal and refitting#
38Remove the distributor cap and place it to
one side, complete with spark plug leads
(photo).
39Turn the crankshaft by means of the
pulley nut, or by raising and turning a front
wheel with top gear engaged, until No. 4
piston is on its firing stroke. This will be
indicated when the contact end of the rotorarm is aligned with the mark on the distributor
body rim, and the lug on the crankshaft pulley
is aligned with the timing pointer on the
engine. The right-hand underwing shield will
have to be removed in order to see the marks
(photo).
40Unscrew the distributor fixing nuts and
withdraw the distributor.
41When fitting the distributor, the offset
drive dog will automatically locate the
distributor rotor in its correct position, but the
distributor body may require rotating in order
to align the rim mark with the rotor. The
elongated slots for the fixing studs are to
permit initial alignment, not for subsequent
adjustment, as advance angle alterations are
carried out automatically by the system ECU
(photos).
42Tighten the nuts and refit the cap with
leads.
43Unless a stroboscope and a vacuum
pressure gauge are available, it will not be
possible to check the advance values with the
engine running. Where these instruments are
available, connect the vacuum gauge to the
inlet manifold, and the stroboscope in
accordance with the equipment manufac-
turer’s instructions. Refer to Fig. 13.79
according to the inlet manifold vacuum
pressure indicated.
Microplex ignition system
components - testing ª
44An ohmmeter and a voltmeter will be
required for these tests.
45Remove the multipin plug from the ECU.
Engine speed sensor
46Insert the probes of an ohmmeter
between terminals 3 and 16 of the multipin
connector; 618 to 748 ohms (1301 cc) or
578 to 782 ohms (1372 cc) should be
indicated.
47If necessary, carry out a check of the gap
between the sensor and flywheel teeth as
described in Chapter 4, Section 10.
Supplement: Revisions and information on later models 13•89
10.39 Crankshaft pulley timing marks
(arrowed)10.38 Removing the distributor cap10.36 Ignition coil (1) and power module (2)
on 1301 cc Turbo ie engine
Fig. 13.78 Rotor aligned with distributor
body rim mark - Microplex ignition system
(Sec 10)
10.41A Distributor body showing elongated
slots in the mounting lugs
Fig. 13.77 Crankshaft pulley timing mark
aligned with timing pointer - Microplex
ignition system (Sec 10)
1 TDC sensor10.41B Distributor drive dog
13

20When reassembling, pack the joint with
special FIAT Tutela MRM2 lubricant; if this is not
available, use molybdenum disulphide grease.
21The reference groove on the outer track
must be assembled so that it is towards the
final drive when refitted (photo).
22Pack the joint and the inside of the boot
liberally with the specified grease.
23If a new joint is being fitted to the shaft,
make sure that the joint and shaft colour
codes match.
Shaft colour Joint colour
Blue Blue or white
Red Red or white
Right-hand driveshaft damper
weight (1108 cc and
1372 cc ie models) -
removal and refitting
#
24A damper weight is fitted to the longer,
right-hand driveshaft to reduce vibration (photo).25It should not be necessary to remove the
damper weight unless the driveshaft is to be
renewed, or the weight has been damaged.
26The weight is in two halves, and can be
removed by simply unscrewing the two clamp
bolts securing the two halves to the
driveshaft. Note that the weight locates on a
rubber mounting which is split along its
length, and can simply be pulled from the
driveshaft for renewal if necessary.
27Refitting is a reversal of removal, but
ensure that the damper weight is positioned
exactly as shown in Fig. 13.101.
14 Braking system
PART A: BRAKING
SYSTEM - GENERAL
Front brake pads - all later
models
1The front brake pads have modified
anti-vibration plates and a wire spring fitted to
prevent them from vibrating and knocking in
operation. 2On some models the clip securing the disc
pad locking block is located on the inboard
end, rather than the outer end (shown in
Chapter 8). To ensure correct reassembly,
check the location of the original block
retaining clip before dismantling the brake
unit. The alternative fixing arrangement is
shown in the accompanying photos, in this
instance on a 1372 cc ie model (photos).
PART B: BRAKING SYSTEM
- TURBO IE MODELS
Description
1Disc brakes are fitted to all four wheels on
the Turbo ie models. The front disc brakes are
of different design from those used on other
models, in that the wear in the pads can be
checked without the need to remove the
caliper cylinder housing.
Front disc pads - renewalª
2Raise the front of the car and remove the
roadwheels.
3Check the thickness of the friction material
on the pads through the aperture in the caliper
cylinder body. If the thickness of the material
is 1.5 mm or less, then the pads on both sides
must be renewed (photo).
13•100 Supplement: Revisions and information on later models
14B.3 Front disc pads (arrowed) on Turbo
ie model14A.2B Front brake locking block
orientation with inboard retaining clip14A.2A Front brake pad locking block is
secured by a clip on the inboard end of the
brake unit on certain models
Fig. 13.101 Correct position of driveshaft damper weight on 1108 cc and 1372 cc ie
models (Sec 13)
Dimensions in mm
13.24 Right-hand driveshaft damper weight
13.21 Outer track reference groove

MOT Test ChecksREF•1
This is a guide to getting your vehicle through the MOT test.
Obviously it will not be possible to examine the vehicle to the same
standard as the professional MOT tester. However, working through
the following checks will enable you to identify any problem areas
before submitting the vehicle for the test.
Where a testable component is in borderline condition, the tester
has discretion in deciding whether to pass or fail it. The basis of such
discretion is whether the tester would be happy for a close relative or
friend to use the vehicle with the component in that condition. If the
vehicle presented is clean and evidently well cared for, the tester may
be more inclined to pass a borderline component than if the vehicle is
scruffy and apparently neglected.
It has only been possible to summarise the test requirements here,
based on the regulations in force at the time of printing. Test standards
are becoming increasingly stringent, although there are some
exemptions for older vehicles. For full details obtain a copy of the Haynes
publication Pass the MOT! (available from stockists of Haynes manuals).
An assistant will be needed to help carry out some of these checks.
The checks have been sub-divided into four categories, as follows:
HandbrakeMTest the operation of the handbrake.
Excessive travel (too many clicks) indicates
incorrect brake or cable adjustment.
MCheck that the handbrake cannot be
released by tapping the lever sideways. Check
the security of the lever mountings.
Footbrake
MDepress the brake pedal and check that it
does not creep down to the floor, indicating a
master cylinder fault. Release the pedal, wait
a few seconds, then depress it again. If the
pedal travels nearly to the floor before firm
resistance is felt, brake adjustment or repair is
necessary. If the pedal feels spongy, there is
air in the hydraulic system which must be
removed by bleeding.MCheck that the brake pedal is secure and in
good condition. Check also for signs of fluid
leaks on the pedal, floor or carpets, which
would indicate failed seals in the brake master
cylinder.
MCheck the servo unit (when applicable) by
operating the brake pedal several times, then
keeping the pedal depressed and starting the
engine. As the engine starts, the pedal will
move down slightly. If not, the vacuum hose or
the servo itself may be faulty.
Steering wheel and column
MExamine the steering wheel for fractures or
looseness of the hub, spokes or rim.
MMove the steering wheel from side to side
and then up and down. Check that the
steering wheel is not loose on the column,
indicating wear or a loose retaining nut.
Continue moving the steering wheel as before,
but also turn it slightly from left to right.
MCheck that the steering wheel is not loose
on the column, and that there is no abnormalmovement of the steering wheel, indicating
wear in the column support bearings or
couplings.
Windscreen and mirrors
MThe windscreen must be free of cracks or
other significant damage within the driver’s
field of view. (Small stone chips are
acceptable.) Rear view mirrors must be
secure, intact, and capable of being adjusted.
1Checks carried out
FROM THE DRIVER’S SEAT
1Checks carried out
FROM THE DRIVER’S
SEAT2Checks carried out
WITH THE VEHICLE
ON THE GROUND3Checks carried out
WITH THE VEHICLE
RAISED AND THE
WHEELS FREE TO
TURN4Checks carried out on
YOUR VEHICLE’S
EXHAUST EMISSION
SYSTEM
REF