1983 FIAT UNO engine

Wiring diagrams 14•1
14
Component key for wiring diagrams 1 to 29
Note: Not all the items listed will be fitted to all models
No Description
00200 Alternator with built-in regulator
00500 Battery
01001 Starter motor
01202 Rear front electric window motor
01203 Left front electric window motor
01206 Windscreen wiper motor
01207 Rear screen wiper motor
01252 Right front door locking motor
01253 Left front door locking motor
01254 Right rear door locking motor
01255 Left rear door locking motor
01400 Windscreen washer pump
01401 Rear screen washer pump
01420 Electric fuel pump
01500 Engine cooling fan
01502 Injector cooling fan
01504 Ventilation fan
02001 Engine cut-out solenoid on injection pump
02010 Fuel injector
02011 Fuel injector
02012 Fuel injector
02013 Fuel injector
02015 Supplementary air valve
02210 Accelerator pump outlet cut-out solenoid on
carburettor
02215 Supplementary air valve
02400 Ignition coil
02405 Ignition coil with electronic control unit
02490 Static advance ignition control unit
02492 Microplex ignition system control unit
03000 Insufficient engine oil pressure switch
03002 Right front door ajar switch
03003 Left front door ajar switch
03004 Right rear door ajar switch
03005 Left rear door ajar switch
03006 Handbrake ‘on’ warning switch
03007 Brake stop-lamp switch
03008 Reversing light switch
03028 Radiator thermostatic switch
03029 Coolant overheating warning light thermostatic switch
03034 Injector cooling fan thermostatic switch
03035 Accelerator pump outlet cut-out solenoid thermostatic
switch
03036 Radiator thermostatic switch with two operating ranges
03053 Map reading light switch
03059 Foglamps switch
03060 Rear foglamp switch
03110 Heated rear screen switch
03114 Ventilation fan switch
03123 Air pressure switch
03142 Choke warning light switch
03144 Reset switch
03145 Display switch
03305 Right front door open light push button
03306 Left front door open light push button No Description
03319 Horn push button
03500 Ignition switch
03505 Butterfly valve cut-off switch
03506 Throttle position switch
03530 Right front electric window switch
03531 Left front electric window switch
03546 Rear screen wash/wipe switch
03550 Hazard warning lights switch
04010 Steering column switch unit, direction indicators
04022 Steering column switch unit, headlamps, main beam
and dipped, side lights
04032 Steering column switch unit, windscreen wash/wipe
04214 Fuel injection system control relay
04215 Antiskid system failure relay
04225 Radiator fan 2nd speed engagement relay feed
04241 Foglamps relay feed
04260 Electric windows motor relay feed
04283 Antiskid system relay
04291 Horn relay feed
04292 Heated rear screen relay feed
04441 Dim-dip cut-out 04600 Ignition distributor
04700 Coolant temperature sender unit
04701 Electronic injection coolant temperature sender unit
04720 Oil pressure sender unit
05008 Right headlamp, main beam and dipped with side light
05009 Left headlamp, main beam and dipped with side light
05013 Abnormal fuel consumption sensor
05015 Right foglamp
05016 Left foglamp
05410 Right front direction indicator
05411 Left front direction indicator
05412 Right front side direction indicator
05413 Left front side direction indicator
05640 Rear number plate lamp
05690 Right rear light cluster, sidelight, direction indicator,
brake light, rear foglamp
05691 Left rear light cluster; side light, direction indicator,
brake light, rear foglamp
06000 Centre courtesy light
06026 Map reading light
06076 Ideogram fibre optic light
06080 Heater controls light
06084 Instrument panel light
06300 Sidelights warning light
06305 Main beam headlamps warning light
06310 Rear foglamps warning light
06311 Foglamps warning light
06315 Hazard warning lights warning light
06320 Direction indicators warning light
06335 Insufficient brake fluid level warning light
06336 Handbrake ‘on’ warning light
06343 Insufficient engine oil pressure warning light
06344 Insufficient brake fluid level warning light
06345 Fuel reserve warning light
06350 Coolant overheating warning light

14•2 Wiring diagrams
No Description
06355 Battery charging warning light
06365 Choke warning light
06368 Antiskid system failure lamp
06385 Heated rear screen warning light
06800 Horn
06801 Right horn
06802 Left horn
07000 Coolant level sensor
07001 Engine oil level sensor
07003 Brake fluid level sensor
07015 Right front brake pad wear sensor
07016 Left front brake pad wear sensor
07020 Engine speed sensor
07021 TDC sensor
07022 Anti-knock sensor
07023 Diagnostic socket
07037 Butterfly valve (cut-off) switch
07050 Fuel gauge
07051 Instant fuel consumption gauge (econometer)
07052 Airflow meter
07060 Idle cut-off device
07107 Roadwheel speed sensors
07109 Vacuum switch
07191 Absolute pressure sensor
07192 Vacuum switch
07400 Fuel gauge
07410 Engine oil temperature gauge
07415 Coolant temperature gauge
07420 Engine oil pressure gauge
07430 Tachometer
07460 Clock
07461 Digital clockNo Description
08051 Ignition coil condenser
09000 Dim-dip transformer
09008 Radiator cooling fan 1st speed resistor
09100 Heated rear screen
10022 Cut-off device electronic control unit
10500 Control (fuse) box
10515 Electronic injection control unit
10571 Central locking control unit
10584 Antiskid system ECU
10586 Pressure modulators
59000 Cigar lighter
60000 Instrument panel
60204 Four place fusebox
70090 General earth
70091 General earth
70092 Earth plate
M Electronic control unit
Wire colour codes
A Light blue
B White
C Orange
G Yellow
H Grey
L Blue
M Brown
N Black
R Red
S Pink
V Green
Z Violet
Example of two-colour wire: BN (White/Black) Component key for wiring diagrams 1 to 29 (continued)
Note: Not all the items listed will be fitted to all models

14•20 Wiring diagrams
Component key for wiring diagrams 30 to 52
Note: Not all the items listed will be fitted to all models
No Description
1 Injector cooling fan
2 Left front light cluster
3 Left foglamp
4 Left front engine compartment earth
5 Radiator cooling fan
6 Double contact thermostatic switch
on engine radiator
6A Thermostatic switch on engine
radiator
7 Left horn
8 Right horn
9 Resistor for engaging radiator fan 1st
speed
10 Right front light cluster
11 Right foglamp
12 Right front engine compartment earth
13 Battery
14 Ignition coil
15 Ignition distributor with magnetic
impulse generator
16 Left front side direction indicator
17 Ignition power module
18 MPi electronic injection control unit
19 Join between injection/ignition cables
in engine compartment
20 Battery cables join in engine
compartment
21 Antiskid braking system wiring join
22 Starting go-ahead relay
23 Earth for battery
24 Radiator coolant temperature sender
unit for electronic injection
25 Anti-knock sensor
26 Injection system diagnostic socket
27 Switch signalling insufficient engine
oil pressure
28 Radiator coolant temperature sender
unit
29 Engine oil temperature sender unit
30 Engine oil pressure sender unit
31 Right front side direction indicator
32 Engine oil temperature sender unit
cable join
33 Battery recharging signal cable join
34 Windscreen washer pump
35 Rear screen washer pump
36 Reversing switch
37 Fuel injectors relay feed
38 Insufficient brake fluid level sensor
39 Left brake pad wear sensor
40 Microplex electronic ignition control
unit
41 Injection cables join in engine
compartment
42 Ignition cables join in engine
compartment
43 Join between battery cable and
injection cables
44 Join between engine cable and
battery cables
45 Left front brake pad cables join
46 Starter motorNo Description
47 Windscreen wiper motor
48 Headlamp washer pump
49 Fuel injector
50 Fuel injector
51 Fuel injector
52 Fuel injector
53 Supplementary air valve
54 Spark plug
55 Spark plug
56 Spark plug
57 Spark plug
58 Excess supercharging pressure
switch
59 Throttle position switch
60 Engine speed sensor
61 Ignition diagnostic socket
62 Connector block
63 Connector block
64 Alternator
65 Thermostatic switch for injector
cooling fan
66 Right brake pad wear sensor
67 TDC sensor
68 Connector block
69 Connector block
70 Connector block
71 Connector block
72 Join with right brake pad cables
73 Electronic earth
74 Power earth
75 Brake stop-lamp switch
76 20 A fuse for central locking
77 10 A fuse for electric fuel pump
78 30 A fuse for radiator cooling fan
79 30 A fuse for electric windows
80 10 A fuse for injector cooling fan
81 20 A fuse for headlamp
wash/wipe
82 20 A fuse for foglamps
83 Junction box with fuses and relays:
E1 Horn relay (for single tone horns
bridge between 86 and 87)
E2 Heated rear screen relay
E3 Heater (bridge between 85 and 30)
84 Join between front cable and rear
cables
85 Join between front cable and door
ajar sensor cables
86 Earth on dashboard, left hand side
87 Earth on dashboard, right hand
side
88 Choke warning light switch
89 Ignition switch
90 Hazard warning lights switch
91 Steering column switch unit
A Rear screen wash/wipe switch
B Horn button
C Direction indicators switch
D Windscreen wiper intermittent
speed selector switch
E Windscreen/headlamp washer
control switchNo Description
F Rear foglamps/headlamp washer
intermittent device switch
G Headlamp dip switch
H External lights switch
I Flasher switch
92 Foglamp relay
93 Electric fuel pump relay
94 Electric windows relay feed
95 Headlamp wash/wipe intermittent
device
96 Direction indicators/hazard warning
lights flasher unit
97 Central locking receiver
98 Central locking control unit
99 Join with brake pad cables
100 Join between engine cable and
dashboard cables
101 Automatic heater cable join
102 Instrument panel
A Foglamps warning light
B Main beam headlamps warning
light
C Side lights warning light
D Rear foglamps warning light
E Heated rear screen warning light
F Hazard warning lights warning
light
G Direction indicators warning light
H Handbrake applied and insufficient
brake fluid level warning light
I Choke warning light
K Instrument panel light bulbs
L Battery recharging warning light
M Insufficient engine oil pressure
warning light
O Antiskid braking system failure
warning light
P Maximum turbocharging pressure
warning light
Q Brake pad wear warning light
R Door ajar warning light
U Fuel level gauge
V Engine oil pressure gauge
W Engine oil temperature gauge
Y Tachometer
Z Coolant temperature gauge
103 Join with remote control central
locking cables
104 Cigar lighter
105 Radio receiver
106 Heater unit
107 Switch unit
A Heated rear screen switch
B Rear foglamps switch
C Switch unit light bulb
D Rear screen wiper switch
E Foglamps switch
F Clock
108 Left front electric window motor
109 Left front central locking geared
motor
110 Switch signalling left front door ajar

Wiring diagrams 14•21
14
Component key for wiring diagrams 30 to 52 (continued)
Note: Not all the items listed will be fitted to all models
No Description
111 Push button on left front pillar for
centre courtesy light
112 Front electric windows switch panel,
driver’s side
113 Join between dashboard cable and
adjustable map reading light cables
114 Join with left front electric window
cables
115 Join between dashboard cable and
rear cables
116 Join between rear cable and courtesy
light cables
117 Left front speaker
118 Handbrake ‘on’ switch
119 Centre courtesy light bulb
119A Adjustable map reading light on rear
view mirror
120 Right front electric window motor
121 Right front central locking geared
motor
122 Switch signalling right front door ajar
123 Push button on right front pillar for
centre courtesy light
124 Electric windows control panel,
passenger side
125 Fuel level gauge
126 Join with right front electric window
cables
127 Join between engine cable and
dashboard cables
128 Right front speaker
129 Left rear light cluster
130 Join between rear cable and luggage
compartment courtesy light
131 Windscreen washer pump wiring join
132 Rear screen washer pump wiring join
133 Left rear earth
134 Rear screen wiper motor
135 Electric fuel pump
136 Rear number plate lamp
137 Heated rear screen
138 Right rear light cluster
139 Rear foglamp go-ahead switch
140 Join between front cable and antiskid
brakes cables
141 Join between front cable and antiskid
brakes cables
142 25 A fuse for antiskid brakes
143 Antiskid braking system control unit
144 Left modulator for antiskid brakes
145 Right modulator for antiskid brakes
146 Sensor on left front wheel
147 Sensor on right front wheel
148 10A fuse for antiskid braking system
149 Vacuum switch for antiskid braking
system
150 Antiskid braking system engagement
relay
151 Antiskid braking system failure
signalling switch
152 Digiplex electronic ignition control
unitNo Description
153 Bosch SPi Mono-Jetronic injection
system control unit
155 Join between engine cable and
injection cables
156 Join between engine cable and rear
cables for SPi system
157 Idle adjustment actuator
158 Throttle position switch
159 Injector current restriction resistor
(SPi)
162 Engine cut-out solenoid
163 Idle cut-out solenoid valve
168 Tachometer electro-magnetic sensor
169 Automatic heater control unit
170 Heater fan
171 Outside temperature sensor
172 Mixed air temperature sensor
173 Air mixture flap electrical control
motor
174 Diagnostic socket for automatic
heater
175 Connector block
176 Connector block
177 Join with cables for automatic heater
178 Radiator coolant circulation solenoid
valve
179 Automatic heater unit:
A Temperature control potentiometer
B Fan speed control potentiometer
C Heater controls light bulbs
D Ideogram signalling automatic
function engaged
E Automatic function engaged
switch
180 Horn
181 Check Panel:
A Insufficient engine oil level warning
light
B Insufficient coolant level warning
light
C Failure with side lights/rear
foglamp/rear number
plate light/braking lights warning light
D Insufficient brake fluid level
warning light
E Door ajar warning light
F Brake pad wear warning light
182 Earth on dashboard
183 Join with cables for central locking
184 Join with cables for central locking
185 Left rear central locking geared motor
186 Right rear central locking geared
motor
187 Contact on choke lever
188 Resistor for inlet manifold heating
189 Pre-heating thermal switch
191 Heated Lambda sensor
192 Lambda sensor protective fuse
193 Silicon diode
194 Join between front cable and injection
cable
197 Connector blockNo Description
198 Rear cable join
199 Insufficient engine oil level sensor
200 Insufficient coolant level sensor
201 Switch signalling left rear door ajar
202 Switch signalling right rear door ajar
203 Switch on gear selector
204 Light for gear selector panel signalling
gear engaged
205 Parking signal not on
206 Connector block
207 Join in engine compartment with
injection cables
208 Petrol vapour cut out-solenoid valve
209 Petrol vapour cut out-solenoid valve
210 Airflow meter
211 Speedometer relay
212 LE2 Jetronic electronic injection
control unit
213 Connector block
214 Connector block
215 Connector block
216 Ignition cable join
217 Join between front cable and
emission control cable
218 Join between front cable and battery
cable
219 Injection system air temperature
sensor
220 Ignition control unit relay feed
225 Front cable join
226 Front cable join
227 Dim-dip circuit cut out switch
228 Dim-dip circuit resistance
229 Dim-dip circuit 7.5 A protective fuse
230 Driver’s side seat heated pad
231 Driver’s seat backrest heated pad
232 10 A protective fuse for driver’s seat
heated pads
233 Foglamps go-ahead switch
234 Driving lights cut out switch
235 Dipped headlamps relay
236 Main beam headlamps relay
237 Join between engine cable and
dashboard cables
Wire colour codes
A Light blue
B White
C Orange
G Yellow
H Grey
L Blue
M Brown
N Black
R Red
S Pink
V Green
Z Violet
Example of two-colour wire:
BN (White/Black)

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

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

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