engine FIAT UNO 1983 Service Repair Manual

1 Electric fan
2 Radiator
3 Thermostat
4 Coolant supply hose (inlet
manifold to heater matrix)
5 Heater matrix6 Coolant return hose (heater
matrix to the manifold pipe)
7 Coolant pump
8 Coolant manifold pipe
9 Coolant supply hose (cylinder
block/crankcase to the
turbocharger)10 Coolant return hose
(turbocharger to the expansion
tank)
11 Coolant supply hose (expansion
tank to the manifold pipe)
12 Expansion tank13 Coolant return hose (radiator to
the manifold pipe)
14 Fan thermostatic switch
15 Coolant supply hose
(thermostat to the radiator)
16 Coolant return hose (radiator to
the expansion tank)
13•56 Supplement: Revisions and information on later models
Fig. 13.29 Cooling system circuit - 1372 cc ie engine (Sec 8C)
Fig. 13.30 Cooling system circuit - 1372 cc Turbo ie engine (Sec 8C)
1 Expansion tank
2 Radiator
3 Electric fan
4 Coolant supply hose (thermostat
to radiator)
5 Coolant manifold pipe
6 Coolant pump
7 Coolant supply hose (thermostat
to heater matrix)
8 Coolant return hose (heater
radiator to manifold pipe)
9 Heater matrix10 Coolant return hose (inlet manifold
to manifold pipe)
11 Coolant return hose (radiator to
manifold pipe)
12 Thermostat
13 Fan thermostatic switch

10Apply suitable sealant to the threads of
the drain plug, then refit and tighten the plug.
11Dispose of the drained coolant safely, or
keep it in a covered container if it is to be
re-used.
12If required, the system can be flushed
through as described in Section 2 of Chap-
ter 2.
13Before attempting to refill the cooling
system, make sure that all hoses have been
reconnected, that the hoses and clips are in
good condition, and that the clips are tight.
Also ensure that the cylinder block drain plug
has been refitted and tightened. Note that an
antifreeze mixture must be used all year round
to prevent corrosion of the engine
components - refer to Section 3, Chapter 2.
14Open the bleed screw in the top of the
expansion tank (photo).
15Remove the expansion tank cap, and fill
the system by slowly pouring the coolant into
the expansion tank to prevent air locks from
forming.
16Top up the coolant until liquid free from air
bubbles emerges from the radiator bleed
screw orifice, then close the bleed screw.
17Continue topping up until the coolant
reaches the Maximum mark on the expansion
tank.
18Start the engine and run it until it reaches
normal operating temperature, then stop the
engine and allow it to cool. Normal operating
temperature is reached when the cooling fancuts into operation. Feel the radiator top hose
to ensure that it is hot. If cool, it indicates an
air lock in the system.
19Check for leaks, particularly around
disturbed components. Check the coolant
level in the expansion tank, and top up if
necessary. Note that the system must be cold
before an accurate level is indicated. There is
a risk of scalding if the expansion tank cap is
removed whilst the system is hot.
Radiator (and cooling fan)
- removal and refitting Á
20Disconnect the battery negative lead.
21Detach the wiring connectors from the
cooling fan and the fan switch located in the
radiator (photos).
22If preferred, the cooling fan unit can be
removed separately from the radiator, by
undoing the attachment bolts and carefully
withdrawing the unit upwards from the
vehicle. Take care not to damage the radiator
core as it is lifted clear (photo).
23Drain the cooling system as described
earlier in this part of the Section, but note that
it will not be necessary to remove the cylinder
block drain plug.
24Undo the retaining screws and remove
the front grille panel.
25Loosen off the retaining clips and detach
the upper coolant hose and the expansion
hose from the radiator.26Note their direction of fitting, then prise
free the radiator retaining clips. Carefully lift
the radiator from the car.
27Refitting is a reversal of the removal
procedure. Ensure that as the radiator is
lowered into position, it engages in the two
rubber location grommets.
28With the radiator (and cooling fan) refitted,
top up the cooling system as described earlier
in this Section (photo).
Thermostat -
removal and refitting Á
Note: A new thermostat cover gasket must be
used on refitting.
29Drain the cooling system as described
earlier in this Section, but note that there is no
need to drain the cylinder block.
30Disconnect the coolant hoses from the
thermostat cover (situated at the gearbox end
of the cylinder head).
31Unscrew the two thermostat cover
securing bolts, noting that the left-hand bolt
may also secure the HT lead bracket, and
remove the thermostat/cover assembly.
Recover the gasket (photo).
32If faulty, the thermostat must be renewed
complete with the housing as an assembly.
33If desired the thermostat can be tested as
described in Chapter 2.
34Refitting is a reversal of removal, bearing
in mind the following points.
Supplement: Revisions and information on later models 13•57
8C.21B Cooling fan switch wiring
connector8C.21A Cooling fan and wiring connector8C.14 Bleed screw location on top of the
expansion tank (arrowed)
8C.31 Thermostat unit removal on the
1372 cc ie engine (distributor removed for
clarity)8C.28 Topping up the radiator coolant level
on the 1372 cc ie engine. Note orientation
of radiator retaining clip (arrowed)8C.22 Cooling fan to radiator securing bolt
13

35Clean the mating faces of the thermostat
cover and cylinder head, and use a new
gasket when refitting the cover.
36Refill the cooling system as described
earlier in this Section.
Coolant pump -
removal and refittingÁ
Note: A new coolant pump gasket must be
used on refitting. If the pump is found to be
worn it must be renewed as a complete unit as
dismantling and repair is not possible.
37Disconnect the battery negative lead.
38Drain the cooling system as described
earlier in this Section.
39Remove the coolant/alternator drivebelt
as described in the next sub-Section.
40Unscrew the four coolant pump securing
bolts, noting that two of the bolts also secure
the alternator adjuster bracket, and withdraw
the pump from the housing (photo). Recover
the gasket.
41Refitting is a reversal of removal, bearing
in mind the following points.
42Use a new gasket between the pump and
the housing.
43Refit and tension the coolant
pump/alternator drivebelt as described in the
next sub-Section.
44On completion, refill the cooling system
as described earlier in this Section.
Coolant pump/alternator
drivebelt - checking,
renewal and tensioning
Á
45At the intervals specified in Section 3 or
“Routine maintenance” at the beginning of
this manual (as applicable), the drivebelt
should be checked and if necessary
re-tensioned.
46Access to the drivebelt is made from the
underside of the car on the right-hand side.
Loosen off the front right-hand roadwheel
retaining bolts, then raise and support the car
on axle stands at the front. Remove the front
roadwheel on the right-hand side.
47Remove the underwing shield from the
right-hand wheel arch by drifting the
compression pins out from the retaining
clips. Prise free the clips and remove the
shield.
48Additional, though somewhat restricted,
access can be obtained from above by
removing the air cleaner unit on the non-Turbo
ie-engine (photo).
49Check the full length of the drivebelt for
cracks and deterioration. It will be necessary
to turn the engine in order to check the
portions of the drivebelt in contact with the
pulleys. If a drivebelt is unserviceable, renew it
as follows (photo).
50Loosen the alternator mounting and
adjuster nuts and bolts and pivot the
alternator towards the cylinder block.51Slip the drivebelt from the alternator,
coolant pump and crankshaft pulleys.
52Fit the new drivebelt around the pulleys,
then lever the alternator away from the
cylinder block until the specified belt tension
is achieved. Lever the alternator using a
wooden or plastic lever at the pulley end to
prevent damage. It is helpful to partially
tighten the adjuster nut before tensioning the
drivebelt (photo).
53When the specified tension has been
achieved, tighten the mounting and adjuster
nuts and bolts (photo).
PART D: HEATER UNIT- LATER
MODELS
Heater unit -
removal and refitting
Á
1The heater unit is removed complete with
the facia/control panel. Commence by
draining the cooling system as described
previously in this Section.
2Disconnect the battery negative lead.
3Refer to Section 15 of this Chapter for
details and remove the ashtray/cigar lighter
and the auxiliary control panel.
4Undo the upper screw retaining the heater
unit to the facia (see Fig. 13.31).
5Remove the radio from the central facia.
6Undo the retaining screw on each side at
the front of the gear lever console. Prise free
13•58 Supplement: Revisions and information on later models
Fig. 13.31 Removing the heater unit-to-
facia upper retaining screw (Sec 8D)8C.53 Tightening the alternator adjuster
nut8C.52 Fitting a new coolant
pump/alternator drivebelt around the
pulleys
8C.49 Alternator/water pump drivebelt and
tensioner viewed from the right-hand
wheel arch8C.48 Top side view of water pump,
alternator and drivebelt8C.40 Coolant pump/alternator bracket
bolt removal

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

8The air cleaner on the 1116 cc and
1299/1301 cc engine is of circular type.
Access to the element is obtained by
extracting the three cover nuts and lifting off
the lid (photos).9The air cleaner casing can be removed after
unscrewing the four nuts which hold it to the
carburettor and the single nut on the camshaft
cover bracket. As the casing is withdrawn,
disconnect the hoses from it (photos).10The thermostatically-controlled cold air
flap opener is similar to that described in
paragraph 7.
11The air cleaner on the 1372 cc ie engine is
of rectangular shape. The element can be
removed after releasing the spring clips at the
front of the unit, followed by the two screws
from its top face. The air cleaner end cover
can then be withdrawn and the element
removed. The air cleaner unit on the 1372 cc
Turbo ie engine is located in the front
right-hand corner of the engine compartment.
Prise free the four clips to release the top
cover and expose the element.
Fuel pump (999 and 1108 cc
carburettor models) -
description, removal
and refitting
Á
12The fuel pump is mechanically-operated
via a pushrod which is in contact with an
eccentric cam on the camshaft. The pump is
of sealed, disposable type - no repair or
cleaning being possible.
13To remove the pump, disconnect the
flexible hoses and unbolt the pump from the
cylinder head. Retain the pushrod and the
insulator block.
14Refitting is a reversal of removal, use new
gaskets, one on each side of the insulator
block.
Fuel tank (999 and 1108 cc
engines)
15In conjunction with the plastic type fuel
tank, the breather and fuel level transmitter
unit have been modified as shown in
Fig. 13.35.
Supplement: Revisions and information on later models 13•61
9A.9A Circular type air cleaner fixing nuts9A.9B Circular type air cleaner nut on the
camshaft cover (arrowed)
9A.8B Circular type air cleaner element9A.8A Air cleaner on the 1116 cc, 1299 cc
and 1301 cc models
Fig. 13.35 Fuel tank and supply circuit on the 999 and 1108 cc engines (Sec 9A)
1 Carburettor 2 Fuel pump 3 Fuel return pipe 4 Fuel feed pipe 5 Tank vent valve 6 Fuel level sender unit
13

PART B:
CARBURETTOR MODELS
Carburettor (Weber 32 TLF) -
description
Warning: Refer to the beginning
of this Section before starting
any work.
1This carburettor is used on the 999 cc
engine and is of the single venturi
downdraught type, with a manually-operated
choke (cold start).
2The unit incorporates an automatic
anti-flooding device, a full power valve and an
accelerator pump (photos).
3The throttle valve block, although
incorporating coolant hose stubs, is not in fact
coolant-heated.4A solenoid-operated idle cut-off valve is
fitted to prevent running-on (dieseling) when
the ignition is switched off.
Carburettor (Weber 32 TLF) -
idle speed and mixture
adjustment
¢
5If the car is not equipped with a rev counter,
connect one in accordance with the
manufacturer’s instructions.
6Have the engine at normal operating
temperature and idling. Turn the idle speed
screw on the carburettor until the speed
matches that specified (photo).
7The idle mixture is set in production, and
the adjustment screw is sealed with a
tamperproof cap. If, however, the idling is not
smooth or the engine or carburettor havebeen extensively overhauled, the mixture may
require adjusting.
8Prise out the tamperproof plug and connect
an exhaust gas analyser to the car in
accordance with the instrument
manufacturer’s instructions (photo).
9With the engine at normal operating
temperature and idling at the specified speed,
turn the mixture screw until the CO
percentage is within the specified tolerance
(photo).
10If an exhaust gas analyser is not available,
turn the mixture screw anti-clockwise to
obtain maximum idle speed and then turn it
clockwise until the speed just starts to drop.
Re-adjust the idle speed screw to bring the
idle speed to the specified level.
11Switch off the engine and remove the test
instruments. It is advisable to fit a new
tamperproof cap to the mixture screw if it is
intended to take the vehicle overseas. This is
required to meet legislation in certain
countries.
Carburettor (Weber 32 TLF)
- removal and refitting ª
12Remove the air cleaner.
13Release the clips and disconnect the fuel
hoses from the carburettor. Take extreme
care that fuel spillage is contained and that
there are no naked flames in the vicinity of the
work area. Do not smoke.
14Disconnect the distributor vacuum hose
from the carburettor.
13•62 Supplement: Revisions and information on later models
9B.9 Mixture adjustment - Weber 32 TLF
carburettor9B.8 Weber 32 TLF 4/250 carburettor
mixture screw location under tamperproof
plug (arrowed)9B.6 Weber 32 TLF 4/250 carburettor idle
speed screw (arrowed)
9B.2E Weber 32 TLF 4/250 carburettor
from above9B.2D Weber 32 TLF 4/250 carburettor
from throttle linkage side
9B.2C Weber 32 TLF 4/250 carburettor
from accelerator pump side9B.2B Weber 32 TLF 4/250 carburettor
from choke linkage side9B.2A Weber 32 TLF 4/250 carburettor
from anti-run-on solenoid valve side

adjustments described in this sub-Section,
however, will require removal of the
carburettor.
39Disconnect the short, curved diaphragm
hose from the top cover.
40Extract the top cover screws, lift the cover
from the carburettor body, and rotate it in
order to release the cranked choke control
rod from its key hole (photo). Mop out the fuel
and clean the jets.
41Check the jet sizes and other components
against those listed in the Specifications, in
case a previous owner has substituted
incorrect components (photo).
42Overhaul procedures are generally as
given in Chapter 3, Section 14 for the Weber
30/32 DMTR, but use the Specifications listed
in this Chapter. Additional overhaul
procedures are given here.
Fuel inlet needle valve
43If a high float level causing flooding of the
carburettor has been evident, first check that
the inlet valve housing is tight, and its washer
is sealing satisfactorily. A leak here will cause
fuel to bypass the inlet valve.
44If the needle valve is to be renewed,
remove it in the following way.
45Access to the fuel inlet needle valve is
obtained by carefully tapping out the float arm
pivot pin. Take care, the pivot pin pillars are
very brittle (photo).
46Unscrew the fuel inlet valve body and
remove the valve and washer.47When refitting the new valve, always use a
new sealing washer.
Float stroke (travel) - see Fig. 3.10
48The float stroke should be between 42.5
and 43.5 mm when measured from the top
cover gasket. Adjust if necessary by bending
the tab on the end of the arm.
Accelerator pump
49Adjustment of the accelerator pump is
very rarely required, but if performance is
suspect, carry out the following operations.
50Fill the carburettor float chamber and then
operate the throttle valve plate lever several
times to prime the pump.
51Position a test tube under the accelerator
pump jet and give ten full strokes of the
throttle lever, pausing between each stroke to
allow fuel to finish dripping.
52The total volume of fuel collected should
be as specified. Adjust the nut on the pump
control if necessary to increase or decrease
the volume of fuel ejected.
General
53When the stage is reached where the
valve plate spindle bushes have worn, then
the carburettor should be renewed complete.
54When reassembling the carburettor, use
new gaskets which can be obtained in a repair
pack.
Carburettor (Weber 32 ICEV
61/250 and DMTE 30/32,
DMTE 30/150) - general
55These carburettor types are fitted to later
models according to engine type. They are
similar in structure and operation to their
equivalents described in Chapter 3. Reference
can therefore be made to that Chapter for the
description and any operations concerning
them, but refer to Section 2 of this Chapter for
their specifications.
Carburettor (Solex
C 30/32-CIC 8) - description
56This carburettor is fitted as an alternative
to the Weber unit on 1116 cc models
produced for certain markets. The removal,
refitting and overhaul procedures are
essentially the same as described earlier for
the Weber carburettors.
PART C:
BOSCH LE2-JETRONIC
FUEL INJECTION SYSTEM
Description
Warning: Refer to the beginning
of this Section before starting
any work.
1The Bosch LE2-Jetronic fuel injection
system, fitted to the 1301 cc Turbo ie model,
is an electronically controlled multi-point
injection (MPi) system.
2The fuel injectors are fed at constant
pressure in relation to inlet manifold vacuum
pressure.
3The system electronic control unit (ECU)
actuates the injectors for variable duration,
and so supplies the precise volume of fuel
required for any given engine speed and load
condition.
4The ECU also monitors the air induction, air
temperature, coolant temperature and throttle
opening as additional parameters to compute
the required opening of the fuel injectors,
giving maximum power with fuel economy.
Fuel supply system
5The fuel supply system consists of an
electric pump and primary filter, located
adjacent to the fuel tank. A fuel pressure peak
damper is located next to the pump (photo).
6Fuel is then pumped through a filter to the
fuel rail and injectors. The injectors are of the
13•66 Supplement: Revisions and information on later models
9C.5 Electric fuel pump/filter/pressure
damper assembly location on a 1301 cc
Turbo ie model
9B.41 Jets on the Weber 30/32 DMTE
carburettor (top cover removed)
9B.45 Float pivot arrangement and needle
valve on the Weber 30/32 DMTE
carburettor
9B.40 Unscrewing a top cover screw from
the Weber 30/32 DMTE carburettor9B.37F Unscrewing a carburettor fixing nut

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