tow FIAT UNO 1983 Service Owner's Manual

133Drain the engine oil from the sump into a
suitable container. Disconnect the lead from
the engine oil level sensor in the sump.
134Where applicable, unscrew and remove
the bolts retaining the gear linkage mounting
bracket and the clutch housing lower cover
bolts. Remove the cover from the clutch
housing.
135Unscrew the sump retaining nuts and
bolts, then lower and remove the sump.
136Unscrew the timing belt rear cover
retaining bolts.
137Move the timing belt rear cover towards
the front of the car to gain access to the
retaining bolt and then unscrew and remove
the three oil seal housing retaining bolts.
Remove the crankshaft front oil seal housing.
138Note the orientation of the seal in its
housing prior to its removal. Support the
underside of the housing and carefully drive
the old oil seal from the housing using a
punch or a tubular drift of suitable diameter.
An alternative method is to punch or drill a
small hole in the face of the oil seal (but take
care not to drill into the housing) and insert a
self-tapping screw into the seal. Withdraw the
seal by gripping the screw with pliers and
pulling the seal from the housing. If necessary,
fit a second screw into the seal on the
opposite side to provide an even pull.
139Clean the mating faces of the housing
and the front of the crankcase using a suitable
scraper.
140Drive or press the new seal into positionin the housing in the reverse order of removal,
but ensure that it is correctly orientated as
noted during removal (photo).
141Refit the oil seal housing with a new
gasket and tighten the retaining bolts to the
specified torque setting (photos).
142Refit the sump as described later in this
Section using a new gasket. Tighten its
retaining nuts and bolts to the specified
torque. Refit the clutch cover and the gear
linkage mounting bracket.
143Fit the new timing belt, adjust its tension
and refit the crankshaft pulley as described
earlier in this Section.
144Reconnect the remaining components
that were detached during removal in the
reverse order and top up the engine oil level to
complete.
Crankshaft rear oil seal -
removal and renewal#
145If the engine is still in the car, disconnect
the battery negative lead.
146Remove the flywheel as described in the
next sub-Section.
147Punch or drill a small hole in the rear face
of the rear oil seal (but take care not to drill
into the housing) and insert a self-tapping
screw into the seal. Withdraw the seal by
gripping the screw with pliers and pulling it
from the housing. If necessary, fit a second
screw into the seal on the opposite side to
provide an even pull.
148Clean the seal housing, then locate the
Supplement: Revisions and information on later models 13•45
Fig. 13.18 Timing belt rear cover bolt
(arrowed) - 1372 cc ie and Turbo ie engines
(Sec 7B)7B.130J Compress spring and refit the split
collets7B.130I . . . and cap
7B.140 Driving a new crankshaft front oil
seal into its housing7B.141B . . . ensuring it is flush with the
face of the cylinder block7B.141A Refit the crankshaft front oil seal
housing . . .
Fig. 13.20 Removing the timing belt rear
cover on the 1372 ie and Turbo ie engines
(Sec 7B)
Fig. 13.19 Unscrew the bolts at the points
indicated to release the gear linkage
mounting bracket - 1372 cc ie and Turbo ie
engines (Sec 7B)
13

necessary renovated as described later in this
Section.
191Commence refitting as follows.
192Clean the backs of the bearing shells and
the recesses in the connecting rods and
big-end caps.
193Lubricate the cylinder bores with engine
oil.
194Fit a ring compressor to No. 1 piston, theninsert the piston and connecting rod into No. 1
cylinder. With No 1 crankpin at its lowest point,
drive the piston carefully into the cylinder with
the wooden handle of a hammer (photos).
Leave enough space between the connecting
rod and the crankshaft to allow the bearing
shell to be fitted. The piston must be fitted with
the cut-out in the piston crown on the auxiliary
shaft side of the engine, and the cylinder identi-
fication marking on the connecting rod and
big-end cap on the coolant pump side of the
engine - see Fig. 13.21.
195Slide the appropriate bearing shell into
position in the connecting rod big-end, then
pull the connecting rod firmly into position on
the crankpin (photo).
196Press the appropriate bearing shell into
position in the big-end cap (photo).
197Oil the crankpin, then fit the big-end
bearing cap with the cylinder identification
marking on the coolant pump side of the
engine, and tighten the nuts to the specified
torque setting (photos).
198Check that the crankshaft turns freely.
199Repeat the procedure in paragraphs 194
to 198 inclusive on the remaining pistons.
200Refit the cylinder head and the sump.
Pistons/connecting rods -
examination and
renovation
#
201The procedures for inspecting and
renovating the pistons and connecting rod
assemblies are in general the same as thatdescribed for the smaller engines in Sec-
tion 18 of Chapter 1. However, the following
additional points should be noted.
202When renewing a gudgeon pin, first
check the fit in the piston. It should be
possible to fit the gudgeon pin using hand
pressure, but the pin should be a tight enough
fit that it does not drop out under its own
weight. Oversize gudgeon pins are available
as spares if necessary. Use new circlips when
refitting the pistons to the connecting rods.
203Before fitting the pistons to their
connecting rods, weigh each piston and
check that their weights are all within 2.5 g of
each other. If not, the heavier pistons must be
lightened by machining metal from the
underside of the small-end bosses. This
operation must be entrusted to a FIAT dealer
or engine reconditioning specialist.
204The pistons should be fitted to the
connecting rods so that the higher, flat side of
the piston crown is on the side of the
connecting rod with the stamped cylinder
identification number, ie the gudgeon pin is
offset towards the cylinder identification
number see Fig. 13.21.
205The piston rings should be fitted with the
word “TOP” on each ring facing uppermost,
or if no marks are visible, as noted during
removal. If a stepped top compression ring is
being fitted, fit the ring with the smaller
diameter of the step uppermost. The ring end
gaps should be offset 120º from each other.
Use two or three old feeler gauges to assist
13•48 Supplement: Revisions and information on later models
7B.197B . . . and tighten the nuts to the
specified torque
Fig. 13.21 Correct orientation of piston
and connecting rod in engine - 1372 cc ie
and Turbo ie engines (Sec 7B)
1 Auxiliary shaft
2 Cylinder identification markings on
connecting rod and big-end cap
Arrow denotes direction of engine rotation
Note offset gudgeon pin
7B.197A . . . then fit the cap . . .7B.196 . . . and big-end bearing cap . . .
7B.195 Assemble the shell bearing to the
connecting rod . . .7B.194B Tapping a piston into its bore7B.194A Fitting a ring compressor to a
piston

fittings are disconnected from the engine and
transmission and positioned out of the way.
Enlist the aid of an assistant to help steady
and guide the power unit down through the
engine compartment as it is removed, If
available, position a suitable engine trolley or
crawler board under the engine/transmission
so that when lowered, the power unit can be
withdrawn from the front end of the vehicle
and moved to the area where it is to be
cleaned and dismantled.
38Carefully lower the engine and
transmission unit, ensuring that no fittings
become snagged. Detach the hoist and
withdraw the power unit from under the
vehicle.
39To separate the engine from the
transmission, unbolt and remove the starter
motor, then unscrew the retaining bolts and
withdraw the transmission from the engine. As
it is withdrawn, do not allow the weight of the
engine or transmission to be taken by the
input shaft.
40To remove the clutch unit, refer to
Chapter 5 for details.
1372 cc Turbo ie
engine/transmission -
removal and separation
#
41The engine and transmission removal and
refitting details for Turbo-engined models are
similar to those described for the non-Turbo
models in the previous sub-Section, but the
following differences should be noted.
42To provide access for the disconnection
of the turbo and related components, first
remove the inlet manifold. Removal of the inlet
manifold and the turbocharger is described in
Section 9 of this Chapter.
43The ignition distributor on the Turbo
engine is driven from the auxiliary shaft and is
mounted at the front of the engine, towards
the timing cover end.
44The right-hand driveshaft has a steady
bearing and this will need to be unbolted and
detached.
Engine dismantling - general
45Refer to Chapter 1, Section 14 for details.
Auxiliary shaft - removal,
inspection and refitting #
46Remove the engine and transmission from
the vehicle as described previously in this
Section part.
47Drain the engine oil and remove the sump
as described in Part B of this Section.
48Remove the oil pump as described in Part
B of this Section.
49Remove the timing belt and the auxiliary
shaft sprocket as described in Part B of this
Section.
50Unscrew the three retaining bolts and
remove the auxiliary shaft cover. Remove the
gasket.
51Withdraw the auxiliary shaft from the
cylinder block.
52Examine the shaft and its bearing bushes
in the cylinder block for signs of excessive
wear and/or damage and renew it if
necessary. Bush renewal is described in
paragraph 79 in this Section.
53The cover gasket and the oil seal should
always be renewed whenever the cover is
removed. To renew the seal, support the
cover on blocks of wood and drive out the old
seal using a suitable drift inserted in the
cut-out in the back of the cover. Clean the
seal location in the housing. Drive the new
seal into place using a suitable metal tube or
socket (photo). The sealing lip must face
towards the cylinder block. Smear the sealing
lips with clean engine oil before installation.
54Commence refitting by lubricating theauxiliary shaft journals with clean engine oil,
then insert the shaft into the cylinder block
(photo).
55Refit the auxiliary shaft cover, using a new
gasket, and tighten the securing bolts
(photos).
56Refit the auxiliary shaft sprocket, timing
belt, cover and crankshaft pulley as described
in Part B of this Section.
57Refit the engine and transmission with
reference to Part D of this Section.
Engine -
complete dismantling#
Warning: Refer to the beginning
of Section 9 before starting any
work.
58Detach and remove the following ancillary
items. Where applicable, refer to the
appropriate Chapter or Section within this
Chapter for more detailed removal instructions.
Engine oil dipstick
Ignition distributor and HT leads
Fuel pump
Alternator
Oil filter
Oil vapour recovery unit
Inlet and exhaust manifolds and associated
fuel injection components (as applicable)
Clutch unit
59Refer to Part B of this Section for details
and remove the timing cover and drivebelt.
60Refer to Part B of this Section for details
and remove the cylinder head unit.
Supplement: Revisions and information on later models 13•51
7C.54 Inserting the auxiliary shaft into the
cylinder block (rear timing belt cover
removed)7C.53 Driving a new oil seal into the
auxiliary shaft cover7C.36C Transmission front mounting
7C.55B . . . and tighten the securing bolts7C.55A Refit the auxiliary shaft cover with
a new gasket . . .
13

61Refer to Part B of this Section for details
and remove the flywheel.
62Refer to the previous sub-Section for
details and remove the auxiliary shaft.
63Refer to Part B of this Section for details
and remove the sump.
64Refer to Part B of this Section for details
and remove the oil pump unit.
65Refer to Part B of this Section for details
and remove the front and rear crankshaft oil
seals.
66Refer to Part B of this Section and remove
the piston/connecting rod assemblies.
67Refer to Part B of this Section for details
and remove the crankshaft and main bearing
assemblies.
Crankshaft and main
bearings - removal#
68Unscrew the securing bolts and remove
the front and rear crankshaft oil seal housings.
Recover the gaskets.
69Check the main bearing caps for identifi-
cation marks and if necessary use a
centre-punch to identify them. Normally the
caps have identifying notches cut into their
top face nearest the timing belt end of the
engine, with the exception of No 5 cap
(flywheel end) which has no marking (photo).
70Before removing the crankshaft, check
that the endfloat is within the specified limits.
Ideally a dial gauge should be used, but
alternatively feeler gauges can be used as
follows. Push the crankshaft as far as possible
towards the timing end of the engine, and
using a feeler gauge, measure the gap
between the rear face of the flywheel
mounting flange on the crankshaft and the
outer face of the thrust washer (photo). Now
push the crankshaft as far as possible in the
opposite direction and take the same
measurement again. The difference between
the two measurements is the crankshaft
endfloat. If the endfloat is outside the
specified limits, new thrustwashers will be
required.
71Unscrew the bolts and tap off the main
bearing caps complete with bearing shells. If
the bearing shells are to be re-used, tape
them to their respective caps.
72Lift the crankshaft from the crankcase.
73Extract the bearing shells from thecrankcase, keeping them identified for
location if they are to be re-used, and recover
the thrust washers from No. 5 main bearing
location.
Engine components -
examination and
renovation
#
74With the engine completely stripped,
clean all the components and examine them
for wear. Each part should be checked and
where necessary renewed or renovated as
described elsewhere in this Section. Renew
main and big-end bearing shells as a matter of
course, unless it is known that they have had
little wear and are in perfect condition.
75If in doubt as to whether to renew a
component which is still just serviceable,
consider the time and effort which will be
incurred should the component fail at an early
date. Obviously the age and expected life of
the vehicle must influence the standards
applied.
76Gaskets, oil seals and O-rings must all be
renewed as a matter of course. FIAT specify
that the main cylinder head bolts should be
renewed after they have been used (ie
tightened) four times - if in any doubt as to the
number of times the bolts have been used,
renew them in any case as a precaution
against possible failure.
77Take the opportunity to renew the engine
core plugs while they are easily accessible.
Knock out the old plugs with a hammer and
chisel or punch. Clean the plug seats, smearthe new plugs with sealant and tap them
squarely into position.
78Clean and examine the cylinder block as
described in paragraphs 2 to 7 of Section 18,
Chapter 1.
79If the auxiliary shaft bushes are
excessively worn or are oval, they must be
renewed. When the new bushes are installed,
they may need to be reamed to suit. The
renewal of the auxiliary shaft bushes is
therefore best entrusted to an engine
reconditioner or FIAT dealer. When the
bushes are renewed, ensure that the oil hole
in each bush is aligned with the oil channel in
the cylinder block.
PART D: ENGINE
REASSEMBLY
Reassembly - general
1Refer to Chapter 1, Section 19.
Crankshaft and main
bearings - refitting#
2Ensure that the crankcase and crankshaft
are thoroughly clean, and that the oilways are
clear. If possible, blow through the oil drillings
with compressed air, and inject clean engine
oil into them.
3Unless they are virtually new, the old main
bearing shells should be renewed. Failure to
do so is a false economy.
4If new bearing shells are being fitted, wipe
away all traces of protective grease.
5Note that there is a tag on the back of each
bearing shell, which engages with a groove in
the relevant seat in the crankcase or bearing
cap.
6Wipe clean the bearing shell locations in the
crankcase with a non-fluffy rag, then lubricate
them and fit the five upper halves of the
bearing shells to their seats. Note that the
centre (No. 3) bearing shell is plain, whereas
all the other shells have oil grooves (photos).
7Fit the thrustwashers to the No. 5 main
bearing shell location, with the grooved side
of each washer facing away from the face of
the cylinder block - ie towards the thrust face
of the crankshaft (photos).
8Wipe the bearing shell locations in the
13•52 Supplement: Revisions and information on later models
7D.6B . . . all others have oil groove7D.6A No. 3 main bearing shell is plain . . .
7C.70 Measuring crankshaft endfloat using
feeler gauge method7C.69 Identification notches on No. 3 main
bearing cap

bearing caps with a soft non-fluffy rag, then fit
the lower halves of the bearing shells to their
seats. Again, note that the centre (No. 3)
bearing shell is plain, whereas all the other
shells have oil grooves (photo).
9Lubricate the crankshaft journals and the
upper and lower main bearing shells with
clean engine oil (photo).
10Carefully lower the crankshaft into the
crankcase (photo). If necessary, seat the
crankshaft using light taps with a
rubber-faced hammer on the crankshaft
balance webs.
11Lubricate the crankshaft main bearing
journals again, the fit the No. 1 bearing cap.
Fit the two securing bolts, and tighten them as
far as possible by hand.
12Fit the No. 5 bearing cap, and as before
tighten the bolts as far as possible by hand.
13Fit the centre and then the intermediate
bearing caps, and again tighten the bolts as
far as possible by hand.
14Check that the markings on the bearing
caps are correctly orientated as noted during
dismantling - ie the identification grooves
should face towards the timing side of the
engine, then working from the centre cap
outwards in a progressive sequence, finally
tighten the bolts to the specified torque
(photo).
15Check that the crankshaft rotates freely.
Some stiffness is to be expected with new
components, but there should be no tight
spots or binding.16Check that crankshaft endfloat is within
the specified limits, as described in paragraph
70 of Part C in this Section.
17Examine the condition of the front and
rear crankshaft oil seals and renew if
necessary with reference to Part B of this
Section. It is advisable to renew the oil seals
as a matter of course unless they are in
perfect condition.
18Lubricate the oil seal lips with clean
engine oil, then carefully fit the front and rear
oil seal housings using new gaskets.
Pistons and connecting rods -
refitting
19Refer to Part B of this Section.
Oil pump - refitting
20Refer to Part B of this Section.
Sump - refitting
21Refer to Part B of this Section.
Flywheel - refitting
22Refer to Part B of this Section. When the
flywheel is bolted in position, refer to Chapter
5 for details and refit the clutch unit.
Auxiliary shaft - refitting
23Refer to Part C of this Section.
Cylinder head - refitting
24Refer to Part B of this Section. Note that
this procedure describes cylinder head
refitting complete with the camshaft housingassembly and manifolds as a complete unit.
Details of refitting the camshaft housing (and
followers) to the cylinder head will be found
separately in Part B.
Timing belt and covers -
refitting
25Refer to Part B of this Section.
Engine/transmission -
reconnection and refitting#
Note: A suitable hoist and lifting tackle will be
required for this operation. New locktabs will
be required for the exhaust
downpipe-to-manifold nuts, and suitable
exhaust assembly paste, will be required when
reconnecting the downpipes to the exhaust
manifold.
26Before attempting to reconnect the
engine to the gearbox, check that the clutch
friction disc is centralised as described in
Chapter 5, Section 8. This is necessary to
ensure that the gearbox input shaft splines
will pass through the splines in the centre of
the friction disc.
27Check that the clutch release arm and
bearing are correctly fitted, and lightly grease
the input shaft splines.
28Mate the engine and gearbox together,
ensuring that the engine adapter plate is
correctly located, and that the gearbox
locates on the dowels in the cylinder block,
then refit the engine-to-gearbox bolts and the
single nut, but do not fully tighten them at this
stage. Ensure that any brackets noted during
Supplement: Revisions and information on later models 13•53
7D.8 Locate the bearing shells into the
main bearing caps . . .7D.7B . . . sliding them into position each
side of the No. 5 main bearing
7DS.14 Tighten the main bearing cap bolts
to the specified torque setting7D.10 Lower the crankshaft into position7D.9 . . . and lubricate the shells
13
7D.7A Locate the thrust washer . . .

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

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

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

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)

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