1983 FIAT UNO catalytic converter

Cooling system................................................................................. 8
Part A: 999 cc engine
Description
Maintenance
Thermostat - removal and refitting
Coolant pump - removal and refitting
Part B: 1301 cc Turbo ie engine
Description
Part C: 1372 cc ie and 1372 cc Turbo ie engines
Description
Maintenance
Cooling system - draining, flushing and refilling
Radiator (and cooling fan) - removal and refitting
Thermostat - removal and refitting
Coolant pump - removal and refitting
Coolant pump/alternator drivebelt - checking, renewal and
tensioning
Part D: Heater unit later models
Heater unit - removal and refitting
Heater unit - dismantling and reassembly
Fuel and exhaust systems............................................................... 9
Part A: General
Unleaded fuel
Air cleaner modified types
Fuel pump (999 cc engine) - description, removal and
refitting
Fuel tank (999 cc engine)
Part B: Carburettor models
Carburettor (Weber 32 TLF) - description
Carburettor (Weber 32 TLF) - idle speed and mixture
Carburettor (Weber 32 TLF) - removal and refitting
Carburettor (Weber 32 TLF) - overhaul
Carburettor (Weber 30/32 DMTE) - general
Carburettor (Weber 30/32 DMTE) - overhaul
Carburettor (Weber 32 ICEV 61/250 and DMTE 30/32,
DMTE 30/150) - general
Carburettor (Solex C 30/32-CIC 8) - description
Part C: Bosch LE-2 Jetronic fuel injection system
Description
Maintenance
Fuel filter - renewal
Air cleaner element - renewal
Idle speed and mixture - adjustment
Fuel injection system - electrical tests
Fuel injection system - mechanical tests
Fuel injection system components - removal and
refitting
Throttle control linkage - general
Fuel tank - general
Part D: Bosch Mono-Jetronic fuel injection system
Description
Maintenance
Fuel filter - renewal
Air cleaner element - renewal
Idle speed and mixture adjustment
Accelerator control system - check and adjustment
Fuel system - depressurisation
Fuel pump and supply - system checks
Fuel pump - removal and refitting
Injector unit - removal and refitting
Intake air temperature sensor - removal and refitting
Fuel injector - removal and refitting
Electronic control unit (ECU) - removal and refitting
Inlet manifold - removal and refitting
Exhaust manifold - removal and refitting
Catalytic converter - general information
Fuel evaporation control system - generalPart E: Bosch L3.1/2 Jetronic fuel injection systems
Description
Fuel system - depressurisation
Maintenance
Fuel filter - renewal
Air cleaner element - renewal
Checks and adjustments
Injection system components - removal and refitting
Part G: Turbocharger system
Description
Precautions
Turbocharger (1301 cc ie engine) - removal and refitting
Turbocharger (1372 cc ie engine) - removal and refitting
Intercooler - removal and refitting
Injector cooling fan - removal and refitting
Fault finding - fuel injection system
Fault finding - turbocharger system
Ignition system................................................................................. 10
General
Ignition timing (all later models)
Breakerless ignition system - description
Distributor (breakerless type) - removal and refitting
Distributor (breakerless type) - overhaul
Breakerless ignition system components - testing
Microplex ignition system - description
Distributor (Microplex) - removal and refitting
Microplex ignition system components - testing
Digiplex 2 ignition system - description
Distributor (Digiplex 2) - removal and refitting
Spark plugs and HT leads - general
Fault finding - Microplex ignition system
Clutch................................................................................................ 11
Clutch pedal adjustment (cable clutch)
Hydraulic clutch - description
Maintenance (hydraulic clutch)
Clutch master cylinder - removal, overhaul and
refitting
Clutch operating cylinder - removal, overhaul and
refitting
Clutch hydraulic system - bleeding
Transmission.................................................................................... 12
Part A: 1301 cc Turbo ie engine
Description
Gearchange linkage - removal and refitting
Gearchange linkage (Antiskid models) - general
Final drive output shafts - description and oil seal
renewal
Part B: 1372 cc ie and 1372 cc Turbo ie engines
Description
Maintenance
Oil level - checking
Oil - renewal
Gearlever and linkages - general
Transmission - removal and refitting
Part C: 999 and 1108 cc with C514 type transmission
Description
Maintenance
Driveshafts........................................................................................ 13
Inboard joint boots (non-Turbo models, September 1987 on) -
modification
Intermediate driveshaft (Turbo ie models)
Inboard CV joints (Turbo ie models - overhaul
Right-hand driveshaft damper weight (1108 and 1372 cc
models) - removal and refitting
13•2 Supplement: Revisions and information on later models

Braking system................................................................................. 14
Part A: Braking system general
Front brake pads all later models
Part B: Braking system - Turbo ie models
Description
Front disc pads - renewal
Front disc caliper - removal and refitting
Front disc caliper - overhaul
Front brake disc - inspection, renovation or renewal
Rear disc pads - renewal
Rear disc caliper - removal, overhaul and refitting
Rear brake disc - inspection, renovation and renewal
Pressure regulating valve
Brake pedal - removal and refitting
Vacuum servo unit and master cylinder - general
Antiskid system - description
Electrical system.............................................................................. 15
Alternator (999 cc models) - removal and refitting
Alternator (later models) - removal and refitting
Alternator brushes - renewal
Starter motor (999 cc models) - removal and refitting
Starter motor (1301 cc Turbo ie, 1372 cc ie, 1372 cc Turbo ie)
- removal and refitting
Starter motor brushes (later models) - renewal
Fuses - later models
Relays (Turbo ie models) - general
Headlamps - later models
Headlamp beam adjusters for load compensation - later models
Headlamp unit removal - later models
Headlamp dim-dip system - description
Front fog lamps bulb/unit - removal and refitting and beam
adjustment
Horn - relocation
Steering column combination switches (later models) - removal
and refittingInstrument panel (Turbo ie models) - removal and refitting
Facia-mounted switches (1301 cc Turbo ie model) - removal
and refitting
Instrument panel (later models) - removal and refitting
Auxiliary control panel (later models) - removal and refitting
Heater control panel (later models) - removal and refitting
Trip master
Interior roof mounted spotlamp, switch and/or clock - removal
and refitting
Central door locking system
Cigar lighter (later models) - removal and refitting
Electrically operated window switches - removal and refitting
Windscreen wiper motor (later models) - removal and refitting
Windscreen washer reservoir (Turbo) - removal and refitting
Tailgate wiper motor (later models) - removal and refitting
Radio Check control system sensors - description
Check control system sensors - testing
Suspension....................................................................................... 16
Front anti-roll bar - removal and refitting
Suspension strut later models
Bodywork.......................................................................................... 17
Plastic components
Rear view mirrors
Door armrest
Tailgate (Turbo ie model) - component removal and refitting
Radiator grille (1301 cc Turbo ie model) - removal and
refitting
Radiator grille (1372 cc ie and 1372 cc Turbo ie models) -
removal and refitting
Bumpers (1301 cc Turbo ie, 1372 cc ie and 1372 cc Turbo ie
models) - removal and refitting
Rear hinged windows - removal and refitting
Door trim panel (Turbo ie model) - removal and refitting
Supplement: Revisions and information on later models 13•3
13
1 Introduction
Since its introduction in 1983, the FIAT Uno
has had a number of modifications and
improvements including the fitting of a twin
choke carburettor, low profile tyres, tinted
windows and remotely-controlled central door
locking.
The major mechanical change was the
introduction of the FIRE (Fully Integrated
Robotised Engine) on 45 and 45S models to
be followed by a new 1108 cc “FIRE” engine
on the 60S model from 1989 on.
A 1301 cc Turbo ie engine model wasavailable for a short period. This model had a
Bosch LE2 Jetronic electronic fuel injection
(ie) and a turbocharger to give added
performance. To uprate the braking to suit,
disc brakes were fitted to the rear in place of
the original drum type brakes.
A 1372 cc engine model was introduced in
1989. Two versions were initially available. A
Bosch Mono-Jetronic single-point fuel
injection (SPi) system, as found on the 70 SX
model and Bosch L3.1 or L3.2 Jetronic
multi-point fuel injection (MPi) systems were
fitted to Turbo models. L3.2 MPi system
models were equipped with catalytic
converters, to improve exhaust emission. All
fuel injection engines are fitted with electroni-
cally controlled engine management systems.
A new style instrument panel, switchgearand a revised facia layout was introduced in
1989.
During 1992, SPi fuel systems were fitted to
the 999 cc and 1108 cc engines, along with
catalytic converters for improved exhaust
emissions.
Five speed transmissions were introduced
to 999 cc models in 1993.
It is recommended that this Supplement is
always referred to before the main Chapters
of the Manual.
Project vehicles
The vehicles used in the preparation of this
supplement, and appearing in many of the
photographic sequences were a 1986 Uno
45S FIRE, a 1988 1301 cc Uno Turbo ie and a
1991 1372 cc Uno SXie.
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321

Initial start-up after major
overhaul
28Refer to Chapter 1, Section 45, but note
that an oil pressure gauge is fitted to indicate
oil pressure.
29Check the ignition static timing as
described in Section 10.
30Check the engine idle speed and CO level
as described in Section 9.
7 Engine-
1372 cc ie and 1372 cc
Turbo ie
PART A: GENERAL
Description
1The 1372 cc engine is similar in design to
the OHC engine fitted to the FIAT Tipo
variants. The engine is of four-cylinder, in-line,
overhead camshaft type, mounted
transversely at the front of the vehicle.
2The crankshaft runs in five main bearings.
Thrustwashers are fitted to the rear (flywheel
end) main bearing in order to control
crankshaft endfloat.
3The connecting rods are attached to the
crankshaft by horizontally split shell-type
big-end bearings. The pistons are attached to
the connecting rods by fully-floating gudgeon
pins which are secured by circlips. The
aluminium alloy pistons are fitted with three
piston rings: two compression rings and an oil
control ring.
4The camshaft is driven by a toothed belt
and operates the valves via bucket and shim
type cam followers. The camshaft is located in
a separate housing on top of the cylinder
head.
5The inlet and exhaust valves are each
closed by double valve springs, and operate
in guides pressed into the cylinder head.
6The auxiliary shaft, which is also driven by
the toothed belt, drives the oil pump.
7Lubrication is by means of a gear type
pump which draws oil through a strainer
located in the sump, and forces it through a
full-flow filter into the engine oil galleries fromwhere it is distributed to the crankshaft,
camshaft and auxiliary shaft. The big-end
bearings are supplied with oil via internal
drillings in the crankshaft. The undersides of
the pistons are cooled by oil spray nozzles
located in each main bearing location in the
crankcase.
8A crankcase ventilation system is
employed, whereby piston blow-by gases are
drawn via an oil separator into the air cleaner,
from where they are drawn into the inlet
manifold and re-burnt with fresh air/fuel
mixture.
9The 1372 cc ie engine is fitted with a Bosch
Mono-Jetronic single point fuel injection (SPi)
system. Whilst the higher performance
1372 cc Turbo ie engine is fitted with a Bosch
L3.1 (L3.2 from 1992) Jetronic multi-point
injection (MPi) system and turbocharger with
intercooler and oil cooling. The L3.2 system
models are fitted with catalytic converters.
Maintenanceª
10At the intervals specified in Section 3 or
“Routine maintenance” at the beginning of
this Manual, carry out the following tasks.
11Check the engine oil level as follows. With
the vehicle parked on level ground, and with
the engine having been stopped for a few
minutes, withdraw the oil level dipstick, wipe it
on a clean rag, and re-insert it fully. Withdraw
the dipstick again and read off the oil level
relative to the MAX and MIN marks. The oil
level should be between the marks. If the level
is at or below the MIN mark, top up through
the filler on the camshaft cover without delay
(photo). The quantity of oil required to raise
the level from MIN to MAX on the dipstick is
approximately 1.0 litre (1.8 pints). Do not
overfill.
12Renew the engine oil and filter as
described in Section 2 of Chapter 1 (photos).
13Check and if necessary adjust the valve
clearances as described in Part B of this
Section.
14Inspect the engine for signs of oil, coolant
or fuel leaks and rectify as necessary.
15Inspect the crankcase ventilation hose for
blockage or damage. Clean or renew as
necessary.
16Check the condition and tension of thetiming belt as described in Part B of this
Section.
17Renew the timing belt as described in
Part B of this Section.
PART B:
OPERATIONS POSSlBLE
WITH ENGINE IN CAR
Valve clearances -
checking and adjustment#
1It is important to ensure that the valve
clearances are set correctly, as incorrect
clearances will result in incorrect valve timing
thus affecting engine performance.
2The clearances must be checked and
adjusted with the engine cold.
3On the ie engine, refer to Section 9 in this
Chapter for details and remove the air cleaner
unit.
4On the ie engine disconnect the crankcase
ventilation hose from the injector unit and
position the hose out of the way.
5On Turbo ie engines, loosen off the clips
and remove the air hose to the inlet manifold
(above the camshaft cover).
6On Turbo ie engines, disconnect the
accelerator cable from the throttle housing
and the support bracket on the camshaft
cover.
7Unscrew the securing nuts and washers
and remove the camshaft cover, noting that
on later models two of the nuts also secure
the hose clip assembly. Recover the gasket.
8Numbering from the front (timing belt) end
of the engine, the exhaust valves are 1, 4, 5
and 8, and the inlet valves are 2, 3, 6 and 7.
Supplement: Revisions and information on later models 13•37
7A.12B Engine oil filter removal using a
strap wrench - 1372 cc engine7A.12A Engine sump drain plug - 1372 cc
engine7A.11 Topping up the engine oil level -
1372 cc engine
Fig. 13.15 Engine oil level dipstick location
and level markings on the 1372 cc ie and
Turbo ie engines (Sec 7A)
13

9 Fuel and exhaust systems
Warning: Many of the
procedures in this Section
require the removal of fuel lines
and connections that may result
in some fuel spillage. Before carrying out
any operation on the fuel system refer to
the precautions given in ‘Safety first!’ at
the beginning of this Manual and follow
them implicitly. Petrol is a highly
dangerous and volatile liquid, and the
precautions necessary when handling it
cannot be overstressed.
Caution: On fuel injection
models, the system is
pressurised, therefore extra
care must be taken when
disconnecting fuel lines. When
disconnecting a fuel line union, loosen the
union slowly, to avoid a sudden release of
pressure that may cause fuel to spray out
and have a container and cloth ready to
catch spillages. Fuel pressure checking
must be entrusted to a Fiat dealer, or other
specialist, who has the necessary special
equipment.
PART A: GENERAL
Unleaded fuel
Note: On models with catalytic convertersonly unleaded petrol must be used - the use
of leaded petrol will destroy the catalyst.
1It is possible to use unleaded fuel (minimum
95 RON) in the following models with the
indicated serial numbers.
Engine Serial number
903 cc 146A.000
146A.046
146A.048
999 cc 156A2.00
1108 cc 160A3.000
1116 cc 138B.000
138B.046
146A4000
146A4.048
1299/1301 cc 138B2.000
138B2.046
149A7.000
1149A7.000
146A2.000
1372 cc 146C1.000
146A8.000
160A1.046
2On all except the 903 cc engine, the use of
unleaded fuel is conditional upon the
avoidance of constant high speeds and
sudden acceleration.
Air cleaner - modified types
3The air cleaner on later models is of the
automatic temperature controlled type. The
need to move the intake control lever to winter
or summer positions is no longer required.
4The air cleaner on the 999 cc engine is ofrectangular shape and the element is
removed for renewal after prising back the
toggle type clips (photos).
5To remove this type of air cleaner,
disconnect the cold and hot air intake hoses
and the large and small breather hoses
(photos).
6Unscrew the nut from the upper casing
section and then release the lower toggle type
clip and lift the air cleaner from the carburettor
(photo). Note the sealing ring between the air
cleaner and the carburettor. Unless the ring is
in good condition, renew it.
7If the thermostatically-controlled cold air
flap opener in the air cleaner casing is faulty
(checked by holding a mirror against the cold
air intake when the engine is warm), renew the
opener (single fixing screw); no repair is
possible (photo).
13•60 Supplement: Revisions and information on later models
9A.7 Air cleaner thermostatic flap opener
on the 999 cc model9A.6 Air cleaner casing nut on the 999 cc
model9A.5C Air cleaner breather hoses on the
999 cc model
9A.5B Air cleaner cold air intake on the
999 cc model
9A.5A Air cleaner hot air intake and lower
retaining clip on the 999 cc model9A.4B Air cleaner element on the 999 cc
model9A.4A Air cleaner toggle clip on the 999 cc
model

necessary processing (photo). A conventional
paper type air filter element is used and this
must be renewed at the specified intervals.
9The ECU is specific to the model type, its
function being to control the fuel system
under all operating conditions, including
starting from cold - it richens the fuel mixture
as required but at the same time prevents
flooding. As the engine temperature rises, the
injection impulses are progressively reduced
until the normal operation temperature is
reached.
10An integral emergency system enables
the fuel injection system to remain operational
in the event of any of the following
components malfunctioning. These items are
the coolant temperature sensor, the air intake
sensor, the Lambda sensor, the idle speed
check actuator and the throttle position
switch. In the event of the throttle position
switch malfunctioning, the fuel system
becomes automatically inoperative.
11The catalytic converter fitted in the
exhaust system minimises the amount of
pollutants which escape into the atmosphere.
The Lambda sensor in the exhaust system
provides the fuel injection system ECU with
constant feedback which enables it to adjust
the mixture to provide the best possible
conditions for the converter to operate. The
fuel tank ventilation is contained within the
system. This is done by feeding any excess
vapours through a carbon filter back into the
engine intake, using solenoids and valves, as
shown in Fig. 13.46.
MaintenanceÁ
12Regularly check the condition and
security of the system hoses and
connections. Also check the system wiring
connections for condition and security.
13At the specified intervals, renew the air
cleaner element and the fuel filter.
Fuel filter - renewalÁ
14The in-line fuel filter is secured to the
right-hand suspension turret in the engine
compartment. To remove the filter, first
depressurize the fuel in the system as
described later in this Part.
13•74 Supplement: Revisions and information on later models
Fig. 13.46 Fuel evaporation control system (Sec 9D)
1 Fuel tank
2 Two-way safety valve
3 Throttle body4 Two-way vapour vent
valve
5 Vapour cut-off solenoid6 Carbon filter
7 Elbi solenoid
8 ECU
9D.8 Atmospheric air intake for air
temperature sensor (1). Also shown are the
supply and return fuel line connections (2
and 3) and the throttle position sensor (4)
Fig. 13.45 Mono-Jetronic fuel injection component locations in the engine compartment
- 1372 cc ie engine (Sec 9D)
1 Injector resistor
2 Lambda sensor signal connector
3 Lambda sensor heating connector
4 Secondary fuel filter
5 Fuel return pipe
6 Fuel supply pipe
7 Coolant temperature sensor
8 ECU9 Injector holder turret
10 Lambda sensor
11 Nut for adjusting accelerator cable
12 Engine speed and TDC sensor connector
13 Ignition control unit
14 Ignition coil
15 Diagnostic socket
16 Fuel pump relay and system relay

air temperature sensor. Undo the retaining
screw and remove the sensor from the
injector unit (photo).
50Refit in the reverse order of removal.
Fuel injector -
removal and refittingÁ
51Depressurise the fuel system as
described previously, then disconnect the
battery negative lead.
52Remove the air cleaner unit.
53Release the injector feed wiring mutliplug
and detach it from the injector.
54Bend over the locking tabs retaining the
injector screws, then undo and remove the
screws. Withdraw the injector retaining collar,
then carefully withdraw the injector (noting its
orientation) followed by its seal.
55Refit in the reverse order of removal.
Always use new seals in the unit and the
retaining collar and lightly lubricate them with
clean engine oil prior to assembly. Take care
not to damage the seals when fitting and also
when the injector is fitted; check that it
engages correctly.
Fuel injection electronic
control unit (ECU) -
removal and refitting
Á
56The control unit is located under the facia
on the driver’s side of the vehicle. Commence
by disconnecting the battery negative lead.
57To gain access to the control unit, detach
and remove the trim panel from the underside
of the facia on the driver’s side of the car.
58Disconnect the wiring multiplug from the
control unit, then undo the retaining screw
and remove the unit from the car (photos).
59Refit in the reverse order of removal.
Inlet manifold -
removal and refittingÁ
60Remove the fuel injector unit as described
previously.
61Drain the cooling system as described in
Section 8 of this Chapter.
62Detach the coolant hose and coolant
temperature sensor from the inlet manifold.
63Unbolt and remove the accelerator
cable/throttle linkage support bracket from
the top of the inlet manifold. The cable can be
left attached to the bracket.64Detach the brake servo vacuum hose
from the connector on the manifold.
65Unscrew and remove the inlet manifold
securing bolts and nuts and remove the
manifold from the cylinder head. As they are
removed, note the location of the fastenings
and their spacers.
66Remove the gasket and clean the mating
faces of the manifold and the cylinder head.
The gasket must be renewed when refitting
the manifold.
67Refitting is a reversal of the removal
procedure. Ensure that the spacers are
correctly located (where applicable) and
tighten the retaining bolts and nuts to the
specified torque settings.
Exhaust manifold -
removal and refittingÁ
68Remove the inlet manifold as described
previously (1372 cc models only).
69Disconnect the Lambda sensor lead
(photo).
70Raise and support the car at the front end
on axle stands to allow sufficient clearance to
work underneath the car and disconnect the
exhaust downpipe from the manifold.
71Straighten the tab washers, then unscrew
and remove the exhaust downpipe-
to-manifold retaining nuts (photo). Detach the
downpipe from the manifold. Support the
downpipe so that the Lambda sensor will not
get knocked and/or damaged.72Undo the manifold-to-cylinder head
securing bolts/nuts and withdraw and remove
the manifold and heat shield.
73Remove the gasket and clean the mating
faces of the manifold, cylinder head and
downpipe flange. The gasket must be
renewed when refitting the manifold.
74Refitting is a reversal of the removal
procedure. Tighten the retaining bolts/nuts to
the specified torque setting.
Catalytic converter -
general information
75The catalytic converter is a reliable and
simple device which needs no maintenance in
itself, but there are some facts of which an
owner should be aware if the converter is to
function properly for its full service life.
a) DO NOT use leaded petrol in a car
equipped with a catalytic converter - the
lead will coat the precious metals,
reducing their converting efficiency and
will eventually destroy the converter.
b) Always keep the ignition and fuel systems
well-maintained in accordance with the
maintenance schedule - particularly, en-
sure that the air cleaner filter element the
fuel filter and the spark plugs are renewed
at the correct interval - if the intake air/fuel
mixture is allowed to become too rich due
to neglect, the unburned surplus will enter
and burn in the catalytic converter,
overheating the element and eventually
destroying the converter.
Supplement: Revisions and information on later models 13•77
9D.58B . . . for access to the ECU retaining
screw (arrowed)9D.58A Detach the multiplug (arrowed) . . .9D.49 Fuel injector unit sensor retaining
screw (1). Also shown is the intake air
temperature sensor (2)
9D.71 Exhaust downpipe to manifold
flange connection showing retaining nuts
and locktabs9D.69 Lambda sensor in exhaust
downpipe
13

c) If the engine develops a misfire, do not
drive the car at all (or at least as little as
possible) until the fault is cured - the
misfire will allow unburned fuel to enter
the converter, which will result in its
overheating, as noted above.
d) DO NOT push- or tow-start the car - this
will soak the catalytic converter in
unburned fuel, causing it to overheat
when the engine does start - see b)
above.
e) DO NOT switch off the ignition at high
engine speeds - if the ignition is switched
off at anything above idle speed,
unburned fuel will enter the (very hot)
catalytic converter, with the possible risk
of its igniting on the element and
damaging the converter.
f) DO NOT use fuel or engine oil additives -
these may contain substances harmful to
the catalytic converter.
g) DO NOT continue to use the car if the
engine burns oil to the extent of leaving a
visible trail of blue smoke - the unburned
carbon deposits will clog the converter
passages and reduce its efficiency; in
severe cases the element will overheat.
h) Remember that the catalytic converter
operates at very high temperatures and
the casing will become hot enough to
ignite combustible materials which brush
against it. DO NOT, therefore, park the car
in dry undergrowth, over long grass or
piles of dead leaves.
i) Remember that the catalytic converter is
FRAGILE - do not strike it with tools
during servicing work, take great care
when working on the exhaust system,
ensure that the converter is well clear of
any jacks or other lifting gear used to raise
the car and do not drive the car over
rough ground road humps, etc., in such a
way as to ground the exhaust system.
j) In some cases, particularly when the car is
new and/or is used for stop/start driving, a
sulphurous smell (like that of rotten eggs)
may be noticed from the exhaust. This is
common to many catalytic
converter-equipped cars and seems to be
due to the small amount of sulphur found
in some petrols reacting with hydrogen in
the exhaust to produce hydrogen sulphide
(H
2S) gas; while this gas is toxic, it is not
produced in sufficient amounts to be a
problem. Once the car has covered a few
thousand miles the problem should
disappear - in the meanwhile a change of
driving style or of the brand of petrol used
may effect a solution.
k) The catalytic converter, used on a
well-maintained and well driven car,
should last for at least 50 000 miles
(80 000 km) or five years - from this point
on, careful checks should be made at all
specified service intervals on the CO level
to ensure that the converter is still
operating efficiently - if the converter is no
longer effective it must be renewed.
Fuel evaporation control system
- general
76As mentioned earlier, fuel evaporation is
contained within the system. In high outdoor
temperatures, when the vehicle is parked for a
period of time, the fuel in the tank evaporates,
building up pressure. When the pressure builds
up to a predetermined level a vent valve opens
to allow the vapours to pass on to and absorbed
by a carbon filter. However, if extreme pressure
or vacuum should build up, a two way safety
valve opens to allow external venting.
77If the safety valve needs replacing, note
that it must be fitted correctly. The black end
should be connected to the fuel tank and the
blue to the carbon filter.
78The vapours in the carbon filter are
flushed by warm air passing through the filter
on to a ECU controlled vapour cut-off
solenoid.
79The cut-off solenoid is closed when
starting the engine and opens to allow
vapours to be drawn into the inlet manifold,
through a second solenoid. If the cut-off
solenoid needs replacing ensure that the
black arrow on the casing is pointing towards
the inlet manifold.
80The second solenoid, known as an Elbi
solenoid, is closed when the engine is turned
off, thus preventing engine run-on. The side
facing connection is for the inlet manifold
pipe.
PART E:
BOSCH L3.1/2 JETRONIC
FUEL INJECTION SYSTEMS
Warning: Refer to the beginning
of this Section before starting
any work.
Description
1A Bosch L3.1 (or L3.2, as fitted from 1992)
Jetronic fuel injection system is fitted to the
1372 cc Turbo ie engine. The system circuit
and main component locations are shown in
Figs. 13.48 and 13.49.
2The L3.1/2 Jetronic system is a multi-point
fuel injection (MPi) system. It operates in a
similar manner to that of the LE2-Jetronic
system fitted to the 1301 cc Turbo ie engine
described in Part C of this Section. The L3.1/2
system is more sophisticated and has the
ability to provide reasonably efficient engine
operation when system sensors malfunction.
As with the LE2 system, the fuel and air
supply mixture circuits are regulated in
accordance with the electronic control unit
(ECU), but on the L3.1/2 system the control
unit is attached to the upper part of the
airflow meter.
3The ECU analyses the information passed
to it from the system sensors. These signals
are then processed and the air/fuel mixture is
constantly adjusted as required to provide the
13•78 Supplement: Revisions and information on later models
Fig. 13.48 Bosch L3.1 Jetronic fuel injection system - 1372 cc Turbo ie engine (Sec 9E)
1 ECU
1A Diagnostic socket
2 Injection system relay and
fuel pump relay
3 Ignition switch
4 Battery
5 Fuel tank
6 Fuel pump
6A Primary fuel filter7 Coolant temperature
sensor
8 Intake air cooling radiator
(intercooler)
9 Air cleaner
10 Supplementary air valve
11 Throttle position switch
11A Throttle housing
12 Airflow meter12A Intake air temperature
sensor
13 Fuel pressure regulator
14 Fuel rail (to injectors)
15 Secondary fuel filter
16 Injectors
17 Injector cooling fan
18 Thermostatic switch (to
engage injector cooling fan)

protective shield to gain access to the pump
which is located forward of the fuel tank.
60Disconnect the fuel hoses and the wiring
connector, release the retaining clamp and
withdraw the pump unit.
Refitting all components
61Refitting of all components is a reversal of
the removal procedure, but note the following
specific points.
62Ensure that all components are clean prior
to refitting and where applicable, use new
seals and gaskets. Ensure that all connectionsare securely and correctly made.
63Do not reconnect the battery until all the
refitting procedures are complete.
64When the engine is restarted, check
around the fuel injection system for any signs
of leakage from the fuel supply and return
components.
Lambda sensor - general
65The sensor is screwed into the exhaust in
front of the catalytic converter.
66A faulty sensor can damage the converter,
therefore it must be checked regularly (see
Maintenance schedule, Section 3) by a dealer
using special equipment.
67Use of leaded fuel will also damage this
sensor, as well the converter.
PART F:
TURBOCHARGER SYSTEM
Description
1A turbocharger is fitted to certain 1301 and
1372 cc ie engines. The accompanying
photographs are all taken from a 1301 cc
engine, but the system is much the same for
both engine types.
2The turbocharger is basically a shaft with an
exhaust gas-driven turbine at one end, and a
compressor located at the other end which
draws in outside air and forces it into the inlet
manifold. By compressing the incoming air, a
larger charge can be let into each cylinder,
and greater power output is achieved than
with normal aspiration.3Lubrication of the turbocharger shaft
bearings is provided by pressurised engine
oil, and the unit is cooled by the coolant from
the engine cooling system.
4A wastegate valve is incorporated in the
turbocharger to divert excessive exhaust gas
pressure from the turbine into the exhaust
pipe at a predetermined pressure level.
5A maximum air pressure switch is located in
the inlet manifold. Its purpose is to cut the
ignition system off when the turbocharger
system pressure continues to increase
beyond 0.86 bars (12.5 lbf/in
2). This would
otherwise damage the engine, due to high
combustion temperatures and pressures
(photo).
6An intercooler (heat exchanger) is located
between the turbocharger and the inlet
manifold. Its function is to cool the inlet
charge, thus increasing its density, to provide
greater power output.
7A mechanical bypass valve is located
between the low-pressure pipe (downstream)
and the high-pressure pipe (upstream), which
reduces the inherent noise from the
turbocharger when the accelerator pedal is
released (photo).
8None of the components of the
turbocharger system can be repaired and
parts are not available. Any fault will therefore
mean that the turbocharger or associated
assemblies will have to be renewed complete.
Precautions
9The following precautions should be
observed when using a turbocharged vehicle.
a) Never operate the engine without the air
cleaner fitted.
b) Never switch off the engine before its
speed has dropped to idling. If the car
has been driven hard, allow it to idle for a
few minutes before switching off. Failure
to observe these recommendations can
cause damage to the turbocharger due to
lack of lubrication.
10Always keep the fuel injection system
well-maintained and tuned. Operating on a
weak mixture can cause overheating of the
turbocharger.
Turbocharger
(1301 cc ie engine) -
removal and refitting
Á
11Disconnect and remove the airflow meter
as described in Section 9C.
12Disconnect the spiral-wound hose from
the fuel injector cooling duct.
13Remove the turbocharger air hoses from
within the left-hand side of the engine
compartment. Note particularly their routing.
14Remove the throttle housing/inlet
manifold as described in Section 9C, also the
fuel rail, injectors and inlet manifold branch
pipe stubs. Remove the alternator heat shield
(photo).
15Remove the exhaust heat shield.
16Unscrew the turbocharger-to-exhaust
pipe flange nuts (photos).
13•82 Supplement: Revisions and information on later models
9F.16A Turbocharger-to-exhaust flange
nut (arrowed)9F.14 Alternator heat shield
9F.7 Bypass valve9F.5 Maximum air pressure switch
(arrowed)
Fig. 13.63 Fuel pump and sender unit
location on the 1372 cc Turbo ie engine
(Sec 9E)
1 Fuel level gauge sender connector
2 Fuel pump connector
3 Fuel return hose
4 Fuel supply hose