wiring FIAT UNO 1983 Service Owner's Guide

solenoid-operated type, actuated from the
ECU.
7Fuel pressure is regulated according to inlet
manifold vacuum pressure by a fuel pressure
regulator. Excess unpressurised fuel is
returned to the fuel tank.
Airflow meter
8This component measures the quantity of
air drawn into the engine, and converts this
into an electric signal which is transmitted to
the ECU.
9The intake air exerts a force on the floating
plate (1) (Fig. 13.39) which is connected to a
potentiometer (2).
10A compensating butterfly valve (3)
compensates for any reflex pressure which
may occur, and is subject to the braking effect
of the damper chamber (4).
11The idle mixture (air/fuel ratio) is altered by
means of the screw (8), which alters the
cross-section of the bypass channel (7).
12An integral-type temperature sensor is
fitted, the resistance value of which decreases
as the temperature of the intake air increases.
This facility is used to correct the mixture
strength within a pre-determined air
temperature range.
Throttle valve housing
13The housing incorporates a conventional
butterfly-type throttle valve, actuated by
cables and rods from the accelerator pedal.
14The idle bypass channel (2) (Fig. 13.40) is
fitted with an adjustment screw (3) to vary the
idle speed.
15The other screw (4) and locknut are usedto set the closing position of the throttle valve
plate.
Supplementary air valve
16This controls the air volume requirement
during cold starting. Essentially, the valve is an
electrically-heated bi-metallic strip, which rotates
the plate (4) (Fig. 13.41) to vary the volume of air
being drawn in through the aperture (1),
according to the temperature of the engine.
17The requirement for additional air during
cold starting is to dilute the additional fuel,
which is injected and controlled by the ECU
as a result of monitoring the engine coolant
temperature sensor.
Electrical control circuit
18The main components of the system are
the ECU and the system control relay. The
relay incorporates a fuel cut-off facility, which
cuts off the fuel supply in the event of engine
failure, the vehicle turning over, or a fuel line
breaking. The relay energises the following
electrical components.
19Coolant temperature sensor, which
signals the coolant temperature to the ECU.
20Throttle position switch, which signals the
ECU when the throttle valve plate is closed, in
order to actuate the deceleration fuel cut-off
device at speeds above 2500 rpm.21The switch also signals the ECU at full
throttle, so that the mixture can be enriched to
cope with full-power requirements.
22The system control relay also monitors the
engine speed directly from the ignition coil
primary winding.
MaintenanceÁ
23Regularly check the security of all system
hoses, wiring connections and plugs.
24At the intervals specified in Section 3,
renew the fuel filter and the air cleaner element.
Fuel filter - renewalÁ
25This is located within the engine
compartment just above the timing belt cover.
Disconnect the fuel hoses, but be prepared
for loss of fuel (photo).
26When fitting the new filter, make sure that
the arrow stamped on it is pointing towards
the fuel injector rail.
Air cleaner element -
renewal
Á
27Prise back the toggle-type clips and take
off the air cleaner lid. Remove and discard the
element, and wipe any dirt from the inside of
the casing (photos).
28Fit the new element and replace the lid.
Supplement: Revisions and information on later models 13•67
Fig. 13.41 Supplementary air valve -
1301 cc Turbo ie engine (Sec 9C)
1 Aperture
2 Bi-metallic strip
3 Passage
4 Rotating plate (closed position)Fig. 13.40 Sectional view of throttle valve
housing - 1301 cc Turbo ie engine (Sec 9C)
1 Butterfly-type throttle valve
2 Idle bypass channel
3 Idle speed adjusting screw
4 Throttle valve plate setting screwFig. 13.39 Sectional view of airflow meter -
1301 cc Turbo ie engine (Sec 9C)
1 Floating plate
2 Potentiometer
3 Compensating butterfly valve
4 Damper chamber
6 Spring
7 Bypass channel
8 CO adjusting screw
9 Tamperproof plug
Terminals
5, 7, 8, Potentiometer
9 Air temperature sensor
E Sealed (not to be touched)
9C.27A Removing the air cleaner lid9C.25 Secondary fuel filter
13

Idle speed and mixture
adjustment¢
29Before carrying out any adjustments, the
engine must be at operating temperature, the
fan having cut in at second speed and then
switched off.
30Release the locknut and turn the main idle
speed screw in the throttle valve housing until
the engine idles at the specified speed. This
should be all that is necessary to obtain the
correct idle speed, as the throttle valve plate
base setting is set during production.
However, if wear has taken place, or incorrect
adjustment has been carried out previously,
proceed in the following way.
31Disconnect the intake duct from the
throttle valve housing. Release the locknut on
the base (small) adjusting screw, and turn thescrew until there is a clearance between the
lower edge of the throttle valve plate and the
throat wall of between 0.05 and 0.1 mm
(photos).
32With the engine still at operating
temperature, start the engine, and having
released the locknut, turn the main (large) idle
speed screw fully clockwise to close the
bypass passage.
33Now turn the base (small) screw until the
engine idles at between 700 and 800 rpm.
Tighten the locknut.
34Finally, turn the main (large) adjusting
screw to give an idle speed of between 800
and 900 rpm.
35It is unlikely that the mixture will require
alteration, but if it does, connect an exhaust
gas analyser to the car in accordance with the
equipment manufacturer’s instructions.
36With the engine at operating temperature,
prise out the tamperproof cap, and turn the
mixture screw, which is located in the airflow
meter, until the CO level is as given in the
Specifications. Turning the screw clockwise
richens the mixture, turning it anti-clockwise
weakens the mixture. Use a close-fitting Allen
key for the adjustment (photo).
Fuel injection system -
electrical testsª
37When carrying out checks to trace a fault
in the system, an ohmmeter should be used
for the following tests.
38Disconnect the multipin connector from
the ECU, and also the one from the system
control relay, and apply the probes of the
ohmmeter in accordance with the following
sequence to check for continuity in thecables. The component wiring plug will of
course be disconnected for the test.
ECU connector Component connector
plug terminal plug terminal
1 1 of ignition coil
2 2 of throttle position
switch
3 3 of throttle position
switch
4 50 of ignition switch
5 Earth
5 5 of airflow meter
7 7 of airflow meter
8 8 of airflow meter
9 9 of airflow meter
9 9 of throttle position
switch
9 18 of supplementary air
valve
9 87 main relay socket
10 10 of coolant temperature
sensor
12 Injector terminals
13 Earth
System control Component connector
relay connector plug terminal
plug terminal
1 1 of ignition coil
15 15 of ignition switch
30 Battery positive
31 Earth
50 50 of ignition switch
87 Injector terminals
87 18 of throttle position
switch
87 9 of ECU multipin socket
87b Fuel pump (fused)
13•68 Supplement: Revisions and information on later models
Fig. 13.42 ECU and component connector plug terminals - 1301 cc Turbo ie engine (Sec 9C)
For colour code see main wiring diagrams
9C.31C Checking throttle valve plate
opening with a feeler blade
9C.36 Using an Allen key to adjust the
mixture (CO level)
9C.31B Idle speed base setting screw (1)
and main adjustment screw (2)9C.31A Disconnecting the throttle valve
housing intake duct9C.27B Removing the air cleaner element

39Now use the ohmmeter to check the
resistance of the following components.
Supplementary air valve
40Resistance between the terminals should
be between 40 and 60 ohms at 20ºC (68ºF).
Airflow meter
41Resistance between terminals 5 and 8 of
the potentiometer should be between 330 and
360 ohms at 20ºC (68ºF).
42Resistance between terminals 8 and 9 of
the internal circuit should be between 190 and
210 ohms at 20ºC (68ºF) and between 170
and 190 ohms at 60ºC (140ºF).
Coolant temperature sensor
43At 20ºC (68ºF) the resistance should be
between 2 and 4 k ohms. At 50ºC (122ºF) the
resistance should be between 600 and
900 ohms. At 90ºC (194ºF) the resistance
should be between 100 and 300 ohms.
Fuel injectors
44The winding resistance should be
between 15 and 17 ohms at 20ºC (68ºF).
Throttle position switch
45With the throttle butterfly valve closed,
there should be continuity between ter-
minals 18 and 2, and with the valve fully open,
there should be no continuity between
terminals 18 and 3.
46The throttle position switch should not be
disturbed unless absolutely necessary. If it
has to be removed, then refit it so that themicroswitch is heard to click immediately the
throttle butterfly is opened.
Fuel injection system -
mechanical tests ª
Fuel pump
47To test the pressure of the fuel pump, a
pressure gauge will be required, connected
into the fuel delivery hose.
48Remove the multipin plug from the system
control relay and bridge terminals 87b and 30.
49Turn the ignition switch on. The pump
should operate and indicate a pressure of
between 2.8 and 3.0 bars (40 and 44 lbf/in
2).
50To check the operation of the peak
pressure regulator, pinch the fuel return hose.
If the fuel pressure increases, the regulator
must be faulty, and should be renewed.
51Check that the fuel pressure increases
when, with the engine idling, the accelerator is
depressed sharply.
Supplementary air valve
52With the engine at normal operating
temperature and idling, pinch the
supplementary air valve hose using a pair of
pliers. The engine speed should not drop by
more than 50 rpm. If it does, renew the valve.
Fuel injection system
components -
removal and refitting
ª
53Disconnect the battery before carrying out
any of the following operations.
Air cleaner
54Remove the cover and filter element as
previously described.
55Disconnect the duct from the air cleaner
casing, and then unbolt and remove the
casing. Note that the lower bracket bolt need
not be completely removed, only unscrewed,
due to the design of the bracket. The air
cleaner metal duct is routed over the top of
the radiator (photos).
Airflow meter
56Release the securing clip and disconnect
the air intake duct (photo).
57Release the securing clip and disconnect
the air outlet duct (photo).
58Disconnect the wiring plug.
59Unscrew the fixing screws and remove
the airflow meter from its mounting bracket.
Supplement: Revisions and information on later models 13•69
9C.55B Removing the air cleaner casing
upper bracket9C.55A Disconnecting the duct from the air
cleanerFig. 13.43 System control relay connector
plug terminals 1301 cc Turbo ie engine
(Sec 9C)
9C.57 Air outlet duct securing clip removal
from airflow meter
9C.55C Air cleaner casing lower bracket
and bolt (arrowed)
9C.56 Air intake duct at airflow meter
(securing clip arrowed)9C.55D Air cleaner metal duct over
radiator
13

Fuel pressure regulator
60Disconnect the vacuum hose from the
regulator (photo).
61Anticipate some loss of pressurised fuel,
and then disconnect the fuel hose from the
regulator. Unbolt and remove the unit.
Excessive air pressure switch
62This is screwed into the end of the inlet
manifold. Disconnect the electrical leads and
unscrew the switch.
Coolant temperature sensor
63This is screwed into the cylinder head and
has wires connected to it. Drain the cooling
system before commencing operations.
64Disconnect the wiring plug and unscrew
the sensor.
Throttle valve housing and inlet
manifold
65Disconnect the air inlet hose from the
throttle valve housing, and also the
supplementary air valve hose.
66Disconnect the throttle control cable by
swivelling the grooved sector and slipping the
cable nipple from its recess.
67Disconnect the wiring plug from the
throttle position (potentiometer) switch.
68Unbolt the fuel pressure regulator/wiring
loom bracket, and also the wiring loom
bracket at the other end of the inlet manifold.
Move the wiring loom aside.
69Unbolt and remove the throttle housing
support bracket.
70Disconnect the vacuum servo hose and
the fuel pressure regulator vacuum hosesfrom the inlet manifold (photos).
71Disconnect the leads from the excessive
air pressure switch.
72Unscrew the inlet manifold fixing nuts.
Note that double nuts are used at the ends of
the manifold in order to secure the exhaust
heat shield (photo). The shield should be
released and lowered to rest on the exhaust
manifold.
73Unscrew and remove the remaining two
nuts now exposed by lowering the heat shield
and lifting the inlet manifold away (photo).
74If necessary, the injectors and cooling
tube can be withdrawn, and the two twin inlet
pipe stubs removed. These are retained with
the exhaust manifolds using nuts and washers
(photo).
Fuel rail and injectors
75Disconnect the fuel delivery hose from the
fuel rail by unscrewing the union nut (photo).
Be prepared for some loss of pressurised fuel.
76Disconnect the fuel return hose.
77Unbolt the fuel pressure regulator and the
wiring loom brackets (photo).
78Disconnect the air intake hose from the
throttle valve housing, and then unbolt and
remove the throttle valve housing support
bracket (photo).
79Disconnect the hose from the injector
cooling fan, and also disconnect the fan
thermo-switch on the underside of the injector
cooling air duct (photo). Disconnect the
injector wiring plugs, and then slide out the
injector cooling air duct.
13•70 Supplement: Revisions and information on later models
9C.77 Wiring loom clip and bracket9C.75 Disconnecting the fuel delivery hose
union9C.74 Removing an inlet manifold twin
pipe stub
9C.73 Removing the inlet manifold9C.72 Double nuts at the end of the inlet
manifold
9C.70B Fuel pressure regulator vacuum
hose connection at the inlet manifold9C.70A Brake servo vacuum hose
connection to inlet manifold9C.60 Fuel pressure regulator

80The injector retaining plate socket-headed
screws may now be removed using an Allen
key. Withdraw the fuel injectors and insulators
(photos).
81New injectors, complete with the fuel rail,
must be purchased as an assembly. Always
use new seals when refitting the injectors and
the insulators (photos).
Electronic control unit (ECU)
82The ECU is located under the right-hand
side of the facia panel.
83Pull off the multipin connector plug and
extract the fixing screws (photo).
System control relay
84This is located adjacent to the airflow
meter. Pull off the multipin connector and
release the relay fixing (photo).
Fuel injector cooling fan
85This is located low down on the left-hand
side of the radiator (photo).
86Remove the spiral-wire-wound hose
which connects with the injector cooling duct.
87Pull off the wiring plug, and unbolt and
remove the fan.
Supplementary air valve
88Disconnect the hoses and wiring plug
from the valve, which is located on the front
face of the engine (photos).
89Unscrew the mounting bracket screws
and withdraw the valve.
Supplement: Revisions and information on later models 13•71
9C.80A Extracting a fuel injector screw9C.79 Fan thermostatic switch on
underside of injector cooling air duct (duct
removed for clarity)
9C.85 Fuel injector cooling fan9C.84 Fuel injector system relay9C.83 ECU multipin plug
9C.81C Injector wiring plug refitting9C.81B Fuel injector cooling air duct
refitting
9C.81A Fuel injectors attached to fuel rail9C.80B Fuel injector removal
13
9C.78 Throttle valve housing support
bracket

Throttle position switch
(potentiometer)
90This is located on the left side of the
throttle valve housing (photo).
91Disconnect the wiring plug, unscrew the
two fixing screws and withdraw the switch.
Fuel filter
92Unscrew the fuel line banjo unions from
the filter, which is located in the right-hand
rear corner of the engine compartment. Be
prepared for some loss of pressurised fuel,
and mop it up with rags.
Fuel pump
93The fuel pump can be removed from its
location beside the fuel tank afterdisconnecting the fuel hoses and wiring plug,
and then releasing the mounting clamp.
Refitting all components
94Refitting of all components is a reversal of
removal, but observe the following points.
95Use new seals and gaskets as applicable,
noting that three rubber seals are used on
each fuel injector and insulator (photos).
96Adjust the throttle position switch as
described in paragraph 46 of this Section.
97When refitting a new fuel filter, make sure
that the arrow marked on it is in the direction
of the fuel flow.
98Apply gasket cement to the threads of the
coolant temperature sensor.
Throttle control linkage -
general
99This is of the cable and rod type. Adjust the
cable by means of the end fitting and nut, to give
the slightest play in the cable when the plastic
socket is engaged with the ball on the link rod
which runs across the camshaft cover (photos).
100Keep the cross-shaft pivots and return
springs lubricated.
Fuel tank - general
101The fuel tank is of metal construction, but
note the plastic anti-blow-back compartment
between the filler cap and the tank. This is
accessible from under the right-hand wheel
arch (photo).
13•72 Supplement: Revisions and information on later models
9C.99B Throttle cable (secondary section)
and cross-shaft9C.99A Throttle cable and end fitting
(primary section)9C.95D Inlet pipe stub gasket
9C.95C Fuel injector insulator seal9C.95B Fuel injector small seal9C.95A Fuel injector large seal
9C.90 Throttle position switch (wiring plug
arrowed)9C.88B Supplementary air valve (arrowed)9C.88A Disconnecting the supplementary
air valve hose from the inlet manifold

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

26Loosen off the knurled retaining nut and
remove the cover from the fuel pump relay.
This is located on the left-hand suspension
turret in the engine compartment (photo).
27Carefully pull free the fuel pump relay,
then start the engine and run it until it stops
(photo). The fuel system is now
depressurised. Turn the ignition off before
removing/dismantling any components.
28Do not refit the fuel pump relay or turn the
ignition on until the system is fully
reconnected. When the engine is ready to be
restarted, refit the relay and its cover, then
restart the engine in the normal manner.
Fuel pump and supply
system checks°
29Specialised equipment is required to
undertake accurate tests in the fuel supply
system and such checks must therefore be
entrusted to a FIAT dealer or a fuel injection
specialist. If the fuel pump is suspected of
malfunction, a basic check can be made by
removing the fuel filler cap then listening
through the filler pipe, get an assistant to turn
on the ignition whilst you listen to hear if the
pump is heard to operate in the tank. If the
pump fails to operate, check that the pump
fuse is sound and that its connection (and
also that of the relay) are clean and secure.
30The pump can be further checked by first
depressurising the fuel system as described in
the previous sub-Section, then disconnect the
fuel supply pipe at the injector unit and locateit in a suitable container. With the fuel pump
relay removed, connect up a suitable test lead
with a 7.5 amp (10 amp on models with
catalyst) fuse, in series, to the relay terminals
30 and 87, and check that fuel flows into the
container from the supply pipe (photo). If a
suitable pressure gauge is available for
connecting into the fuel line between the
engine compartment fuel filter and the
injection unit, check that the fuel pressure is
as specified at the beginning of this Chapter.
31If the pump fails to operate, check that the
battery is in good condition and that the pump
wiring connections are clean and secure
before condemning the pump. To remove the
pump unit from the fuel tank, proceed as
described in the following sub-Section.
Fuel pump -
removal and refittingÁ
32Release the pressure from the fuel system
as described previously.
33Move the front seats forward, then tilt the
rear seat cushions forward. Peel back the
luggage area floor cover from the right-hand
side towards the centre to expose the access
cover above the pump/sender unit in the floor.
Remove the access cover.
34Detach the wiring connectors from the
pump unit and the fuel level sender unit.
35Loosen off the hose retaining clips and
detach the fuel supply and return hoses from
the pump unit connections. Mark the hosesfor identity to avoid incorrect attachment
during refitting.
36Unscrew the retaining nuts then carefully
lift out and withdraw the fuel pump/level
sender unit from the fuel tank.
37Refitting is a reversal of the removal
procedure. A new seal gasket must be used
and it is important to ensure that all
connections are securely and correctly made.
Injector unit -
removal and refittingÁ
38Depressurise the fuel system as
described previously, then disconnect the
battery negative lead.
39Remove the air cleaner unit and the
rubber seal (photo).
40Disconnect the engine idle speed check
actuator lead and the throttle position switch
lead from the side faces of the injector unit.
41Undo the retaining clips and detach the
fuel supply and return hose from the injector
unit. If crimped type retaining clips are fitted,
they will have to be carefully cut free and new
screw type clips obtained to replace them.
Take care not to cut into the hoses when
releasing the crimped type clips.
42Detach the crankcase ventilation hose
from the fuel injector unit.
43Disconnect the accelerator linkage at the
throttle lever on the injector unit.
44Undo the four retaining screws and lift the
injector unit from the inlet manifold. Remove
the gasket (photo).
45Clean the injector unit and the inlet
manifold mating faces.
46Refit in the reverse order of removal.
Intake air temperature
sensor - removal and
refitting
Á
47The air temperature sensor is located in
the top of the injector unit. It is basically a
resistor which varies its value in accordance
with the air temperature entering the induction
circuit from the air filter. The sensor can then
transmit the registered air temperature at this
point to the ECU temperature sensor (2).
48Remove the air cleaner unit and its
mounting bracket in the injector.
49Disconnect the wiring connector from the
13•76 Supplement: Revisions and information on later models
9D.44 Injector unit retaining screws
(arrowed)9D.39 Removing the filter seal from the
injector unit
9D.30 Test lead connected to relay
terminals 30 and 879D.27 Fuel pump relay removal9D.26 Fuel pump relay (1), injection control
relay (2), Lambda sensor fuse (3) and pump
fuse (4) with cover (5) removed

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

optimum engine operating efficiency. In the
event of a system sensor malfunction, errors
in data passed to the ECU are overcome by
an emergency operation, whereby the ECU
supplies the injectors with one of two set
injection periods independent of the sensors.
One period (2.2 ms) is for idle speed and the
other (2.5 ms) is for speeds above idle
(actuated when the idle speed contact is
opened).
4An injection system relay and a fuel pump
relay are fitted and are located in the engine
compartment, adjacent to the ECU on the left-
hand inner wing panel. In the event of the
engine not being started within two seconds of
the ignition being switched to the “ON”
position, the fuel pump relay is deactivated.
The fuel pump circuit fuse is located in the
main fuse block located under the facia within
the car. Note: To avoid possible damage to the
ECU, it is essential that the ignition is switched
off before disconnecting (or connecting) the
wiring multi-plug from the ECU.A Lambda (or
oxygen) sensor is fitted to L3.2 equipped
models, to measure exhaust gas oxygen
content. In sending signals to the ECU,
optimum catalyst operation is maintained.
Fuel system -
depressurisationÁ
5The fuel system should always be
depressurised whenever any fuel hoses
and/or system components are disconnected
and/or removed. This can easily be achieved
as follows.
6The fuel pump relay is located next to the
ECU and airflow meter in the engine
compartment. Carefully pull free the fuel
pump relay, then start the engine and run it
until it stops. The fuel system is now
depressurised. Turn the ignition off before
removing/dismantling any components.
7Do not refit the fuel pump relay or turn the
ignition on until the system is fully
reconnected. When the engine is ready to be
restarted, refit the relay and its cover, then
restart the engine in the normal manner.
MaintenanceÁ
8Regularly check the condition and security
of the system hoses and connections. Also
check the system wiring connections for
condition and security.9At the specified intervals, renew the air
cleaner element and the fuel filter.
Fuel filter - renewalÁ
10This is located in the engine compartment
on the right-hand side. Disconnect the fuel
inlet and outlet hoses, but be prepared for the
loss of fuel. Loosen off the clamp and remove
the filter.
11Reverse the removal procedure to fit the
new filter, but ensure that the arrow indicating
fuel flow is pointing towards the fuel injector rail.
Air cleaner element -
renewalÁ
12Prise free the four retaining clips, then
remove the cover and the air cleaner element.13Wipe clean the inside surfaces of the air
cleaner housing, then insert the new element,
refit the cover and secure it with the four
retaining clips.
Checks and adjustments°
Engine idle speed and mixture
adjustment
14Before carrying out any adjustments, the
engine must be at its normal operating
temperature, the cooling fan having cut into
Supplement: Revisions and information on later models 13•79
Fig. 13.49 Fuel injection system components layout in engine compartment on the
1372 cc Turbo ie engine (Sec 9E)
1 ECU
1A Diagnostic socket
2 Ignition system relay and
fuel pump relay
7 Coolant temperature
sensor10 Supplementary air valve
11 Throttle position switch
11A Throttle housing
12 Airflow meter
13 Fuel pressure regulator
15 Secondary fuel filter16 Injectors
17 Injector cooling fan
18 Thermostatic switch (to
engage injector cooling
fan)
Fig. 13.52 Idle speed adjustment screw (1)
on the 1372 cc Turbo ie engine (Sec 9E)
Note method of compressing the
supplementary air valve pipe (arrowed)
Fig. 13.51 Air cleaner cover securing clips
(arrowed) on the 1372 cc Turbo ie engine
(Sec 9E)Fig. 13.50 Secondary fuel filter with arrows
indicating direction of flow - 1372 cc Turbo
ie engine (Sec 9E)
13