battery FIAT UNO 1983 Service Service Manual

98Commence reassembly by liberally oiling
the bearings in the housing, and the oil seal lip.
99Carefully insert the camshaft into the
housing from the blanking plate/distributor
end, taking care to avoid damage to the
bearings.
100Refit the blanking plate using a new
gasket.
101Refit the camshaft housing as described
previously in this Section.
Cylinder head
(1372 cc ie engine) -
removal and refitting
#
Note: The following instructions describe
cylinder head removal and refitting leaving the
camshaft, manifolds and associated items in situ
In the head. If required, these items can be
removed separately. When removing the
cylinder head the engine must be cold - do not
remove the head from a hot engine. A new
cylinder head gasket and any associated gaskets
must be used during reassembly. 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 that they have been used renew them as a
precaution against possible failure.
Warning: Refer to the beginning
of Section 9 before starting any
work.
102Depressurise the fuel supply system as
described in Section 9 of this Chapter.
103Disconnect the battery negative lead.
104Drain the engine coolant as described in
Section 8.
105Remove the air cleaner unit as described
in Section 9.
106Remove the timing belt as described
previously in this Section.107Disconnect the crankcase ventilation
hose from the cylinder head and the SPi
injector unit.
108Disconnect the accelerator cable at the
engine end.
109Detach the engine idle speed check
actuator lead, the inlet manifold vacuum
sensor lead, the coolant temperature sensor
lead, the injector supply lead, the throttle
position switch lead and the distributor cap
(with HT leads). Position them out of the way.
110Disconnect the brake servo hose from
the manifold.
111Disconnect the coolant hoses from the
thermostat and the inlet manifold.
112Slowly release the fuel supply and return
hose retaining clips and detach the hoses
from the injector unit housing and
connections. Catch any fuel spillage in a clean
cloth and plug the hoses to prevent the
ingress of dirt and further fuel loss.
113Unbolt and detach the exhaust downpipe
from the manifold.
114Loosen off the cylinder head retaining
bolts in a progressive manner, reversing the
sequence shown in Fig. 13.17. When all of the
bolts are loosened off, extract them and
collect the washers.
115Check that all fittings and associated
attachments are clear of the cylinder head,
then carefully lift the head from the cylinder
block. If necessary tap the head lightly with a
soft-faced mallet to free it from the block, but
do not lever it free between the joint faces.
Note that the cylinder head is located on
dowels.116Recover the old cylinder head gasket and
discard it.
117Clean the cylinder head and block mating
surfaces by careful scraping. Take care not to
damage the cylinder head - it is manufactured in
light alloy and is easily scored. Cover the coolant
passages and other openings to prevent dirt and
carbon from falling into them. Mop out all the oil
from the cylinder head bolt holes - if oil is left in
them, hydraulic pressure, caused when the bolts
are refitted, could cause the block to crack.
118If required the cylinder head can be
dismantled and overhauled as described in
paragraphs 129 to 131 of this Section.
119The new gasket must be removed from
its protective packing just before it is fitted.
Do not allow any oil or grease to come into
contact with the gasket. Commence refitting
the cylinder head by locating the new gasket
on the cylinder block so that the word “ALTO”
is facing up (photo).
120With the mating faces scrupulously
clean, refit the cylinder head into position and
engage it over the dowels. Refer to the note at
the beginning of this part of the Section, then
refit the ten main cylinder head bolts and
washers. Screw each bolt in as far as possible
by hand to start with. Do not fit the smaller
(M8 x 1.25) bolts at this stage (photos).
121The bolts must now be tightened in stages
and in the sequence shown in Fig. 13.17. Refer
to the specified torque wrench settings and
tighten all bolts to the Stage 1 torque, then
using a suitable angle gauge, tighten them to
the second stage, then the third stage (photos).
122With the main cylinder head bolts fully
Supplement: Revisions and information on later models 13•43
7B.120B . . . and engage the positioning
dowels in their holes7B.120A Lower the cylinder head onto the
block . . .7B.119 Locating a new cylinder head
gasket on the cylinder block (engine
shown on dismantling stand)
7B.121A Tighten main cylinder head bolts
to specified torque . . .Fig. 13.17 Cylinder head bolt tightening
sequence on the 1372 cc ie and Turbo ie
engines (Sec 7B)
13
7B.121B . . . and then through the specified
angle

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

fitting, as during removal. Note that the
compression rings are brittle, and will snap if
expanded too far.
206If new pistons are to be fitted, they must
be selected from the grades available, after
measuring the cylinder bores. Normally, the
appropriate oversize pistons are supplied by
the dealer when the block is rebored.
207Whenever new piston rings are being
installed, the glaze on the original cylinder
bores should be removed using either
abrasive paper or a glaze-removing tool in an
electric drill. If abrasive paper is used, use
strokes at 60º to the bore centre-line, to
create a cross-hatching effect.
Engine/transmission
mountings - renewalÁ
208The engine/gearbox assembly is
suspended in the engine compartment on
three mountings, two of which are attached to
the gearbox, and one to the engine.
Right-hand mounting
209Apply the handbrake, then jack up the
front of the vehicle and support it securely on
axle stands.
210Suitable lifting tackle must now be
attached to the engine in order to support it as
the engine mounting is removed. No lifting
brackets are provided, so care must be taken
when deciding on an engine lifting point. In the
workshop, a right-angled bracket was made up
by bending a suitable piece of steel plate. The
bracket was then bolted to the engine using the
rear right-hand camshaft housing securing bolt
with suitable packing washers.
211Attach the lifting tackle to the bracket on
the engine and just take the weight of the
assembly.
212Working under the vehicle, unbolt the
engine mounting bracket from the cylinder
block, and unbolt the mounting from the
body, then withdraw the bracket/mounting
assembly.
213Unscrew the nut and through-bolt,
counter holding the bolt with a second
spanner or socket, and separate the mounting
from the bracket.
214Fit the new mounting to the bracket, and
tighten the nut to the specified torque, while
counterholding the through-bolt using a
suitable spanner or socket.
215Refit the mounting bracket to the cylinder
block, and tighten the securing bolts to the
specified torque.
216Refit the mounting to the body and
tighten the securing bolts to the specified
torque.
217Disconnect the lifting tackle from the
engine, and remove the engine lifting bracket.
218Lower the vehicle to the ground.
Left-hand mountings
219Apply the handbrake, then jack up the
front of the vehicle and support it securely on
axle stands.
220Suitable lifting tackle must now be
attached to the gearbox lifting bracket inorder to support the weight of the assembly
as the mounting is removed.
221Attach the lifting tackle to the bracket on
the gearbox, and just take the weight of the
assembly.
222Working under the vehicle, unbolt the
mounting bracket from the gearbox, and
unbolt the mounting from the body, then
withdraw the bracket/mounting assembly.
223Proceed as described in paragraphs 213
and 214.
224Refit the mounting bracket to the
gearbox, and tighten the securing bolts to the
specified torque.
225Refit the mounting to the body and
tighten the mounting bolts to the specified
torque.
226Disconnect the lifting tackle from the
engine.
227Lower the vehicle to the ground.
PART C: ENGINE REMOVAL
AND DISMANTLING
Method of removal - general
1The engine (complete with transmission) is
disconnected and lowered downwards
through the engine compartment, then
withdrawn from the front underside of the car.
1372 cc engine/
transmission - removal
and separation
#
Warning: Refer to the beginning
of Section 9 before starting any
work.
2Depressurize the fuel system as described
in Section 9 of this Chapter.
3Disconnect the battery negative lead.
4Mark the position of the hinges on the
underside of the bonnet, then with the aid of
an assistant, unscrew the hinge bolts and lift
the bonnet clear of the car. Store the bonnet
in a safe area.
5Drain the engine coolant.
6Drain the engine and transmission oils.
7Disconnect and remove the air filter.
8Disconnect the coolant hoses from the
engine, including the hose to the inlet
manifold.
9Detach the ignition coil (HT) lead from the
distributor.10Compress the retaining clip and detach
the engine idle speed actuator lead from the
SPi unit (photo).
11Disconnect the brake servo vacuum pipe
from its connector on the inlet manifold.
12Disconnect the throttle cable from the SPi
unit.
13Disconnect the engine speed sensor lead.
14Release and detach the reversing light
lead from the switch on the transmission
(photo).
15Before disconnecting the hydraulic hose
from the clutch slave cylinder, remove the
filler cap from the reservoir and place a piece
of polythene sheet over the filler neck, then
refit the cap; this will help prevent excess fluid
loss. Once disconnected, plug the hose and
its cylinder connection to prevent the ingress
of dirt into the hydraulic system.
16Disconnect the wiring connector from the
alternator.
17Position a clean rag under the fuel supply
and return hose connections to the SPi unit,
then slowly unscrew the hose clips to release
the system pressure; catch fuel leakage in the
rag and dispose of it safely. Detach the hoses
and plug them to prevent ingress of dirt and
any further fuel leakage. Position the hoses
out of the way.
18Detach the wiring connector from the
engine coolant temperature sender unit
(photo).
19Release the retaining clip and detach the
wiring connector from the throttle position
switch. Also detach the associated earth
leads from the cylinder head.
Supplement: Revisions and information on later models 13•49
7C.14 Reversing light switch and lead7C.18 Engine coolant temperature sender
and wiring connector
7C.10 Engine idle speed actuator/SPi unit
lead connection (arrowed)
13

removal are in place under the
engine-to-gearbox bolts. Do not allow the
weight of the gearbox to hang on the input
shaft as it is engaged with the clutch friction
disc.
29Refit the starter motor, ensuring that the
wiring harness bracket is in position on the
top bolt.
30Locate the engine/transmission unit at the
front of the car and move it into position under
the engine compartment. Attach the lifting
sling and hoist as during removal.
31Enlist the aid of an assistant to help
steady the combined units as they are raised
into position and to locate the mountings in
the engine compartment.
32Once they are located, tighten the
mountings to the specified torque settings,
then disconnect the lifting hoist and sling.
33The remainder of the refitting and
reconnection procedures are a reversal of the
removal procedure described in Part C. For
further details on reconnecting the
suspension and driveshaft components,
refer to Chapter 7 and Section 13 of this
Chapter.
34Ensure that the exhaust downpipe-to-
manifold connection is clean and renew the
gasket when reconnecting this joint. Use a
smear of exhaust assembly paste on the jointfaces. Use new lockwashers and tighten the
flange nuts securely.
35Ensure that all fuel and coolant
connections are cleanly and securely made.
36Ensure that all wiring connections are
correct and securely made.
37Top up the engine and transmission oil
levels.
38Refill the cooling system.
39Check that all connections are securely
made, then reconnect the battery negative
lead.
Initial start-up after major
overhaul
40Refer to Chapter 1, Section 45.
8 Cooling system
PART A:
999 AND 1108 CC ENGINES
Description
1The operation and function of the cooling
system is essentially as described in Chapter
2 but note the location of the various
components and the routing of the coolant
hoses in Fig. 13.26.
Maintenance
2Topping-up, draining and refilling
procedures are as for 1116 and 1301 cc
engines in Chapter 2, but note that the
coolant capacity is different (see Specifica-
tions).
Thermostat -
removal and refittingÁ
3The thermostat is located on the left-hand
end of the cylinder head, below the
distributor.
4The thermostat cannot be renewed
independently of its housing and if faulty the
complete assembly must be renewed.
5Drain the cooling system.
6Although the thermostat housing can be
removed directly from the cylinder head,
better access is provided if the distributor is
first withdrawn as described in Section 10 of
this Chapter (photo).
7Disconnect the coolant hose from the
thermostat housing and unscrew the housing
flange bolts. Remove the assembly. Note that
it may be necessary to tap it free with a
plastic-faced or wooden mallet if stuck in
place.
8Remove the gasket and clean the mating
surfaces.
9Use a new gasket and bolt the assembly
into position (photo).
10Reconnect the coolant hose, then fill and
bleed the cooling system.
13•54 Supplement: Revisions and information on later models
Fig. 13.26 Cooling system circuit - 999 and 1108 cc engines (Sec 8A)
1 Coolant pump 2 Thermostat 3 Heater matrix
Fig. 13.27 Cooling system thermostat in open and closed positions - 999 and 1108 cc
engines (Sec 8A)8A.9 Fitting the thermostat housing. Note
the new gasket
8A.6 The thermostat housing (shown with
distributor removal) on the 999 cc engine

Coolant pump -
removal and refitting#
11The coolant pump is located on the
crankshaft pulley end of the engine and is
driven by the timing belt.
12The pump cannot be repaired and must
be regarded as disposable.
13Drain the cooling system.
14Remove the timing belt cover and then set
No. 1 piston to TDC. To achieve this, turn the
crankshaft pulley bolt until the camshaft
sprocket timing mark is aligned with the one
on the cylinder head.
15Release the belt tensioner and slip the
timing belt off the camshaft and coolant pump
sprockets.
16Unbolt and remove the coolant pump and
clean the mounting face of all old gasket
material.
17Apply a continuous bead of RTV silicone
sealant (instant gasket) to the mounting face
of the coolant pump and bolt it into position
(photos).
18Check that the camshaft sprocket and the
crankshaft have not been moved and fit the
timing belt to the camshaft and coolant pump
sprockets. The pump sprocket does not
require setting in any particular position
before connecting the timing belt.
19Tension the belt as described in Sec-
tion 5B of this Chapter.
20Fit the timing belt cover.
21After allowing one hour for the gasket
material to cure, refill and bleed the cooling
system.
PART B:
1301 CC TURBO IE ENGINE
Description
1The cooling system on this model has flow
and return connections to the turbocharger,
and is an essential means of cooling the
turbocharger.
2The radiator cooling fan is of two-speed
type, being controlled by a two-stage
thermostatic switch screwed into the radiator
side tank.
3According to the coolant temperature level,
the fan speed is regulated to provide the most
effective cooling.
4The remote cooling system expansion tank
is mounted in the left-hand rear corner of the
engine compartment (photo).
PART C:
1372 CC IE AND 1372 CC
TURBO IE ENGINES
Description
1The cooling system layout and components
for the 1372 cc engines is shown in
Figs. 13.29 and 13.30.
2The system on each engine operates in
essentially the same manner as that
described for the other models in Chapter 2,
but the location of components and the
coolant hose routings differ according to
model. The cooling system expansion tank
location differs according to model, being
either located on the side of the radiator ormounted separately on the side of the inner
wing panel.
3On Turbo models, the cooling system also
assists in cooling the turbocharger.
Maintenance
4The maintenance procedures are
essentially the same as those described for
the other models in Chapter 2.
Cooling system - draining,
flushing and refillingÁ
Warning: Wait until the engine is
cold before starting this
procedure. Do not allow
antifreeze to come into contact
with your skin or painted surfaces of the
vehicle. Rinse off spills immediately with
plenty of water. Never leave antifreeze
lying around in an open container or in a
puddle in the driveway or on the garage
floor. Children and pets are attracted by its
sweet smell. Antifreeze is fatal if ingested.
5Disconnect the battery negative lead.
6Working inside the vehicle, turn the heater
temperature control knob fully to the right,
which will fully open the heater coolant valve.
7With the expansion tank cap removed,
place a suitable container beneath the
radiator bottom hose.
8Loosen the clip and ease the bottom hose
away from the radiator outlet (photo). Allow
the coolant to drain into the container.
9Reposition the container under the front of
the cylinder block, and unscrew the cylinder
block drain plug (photo). Allow the coolant to
drain into the container.
Supplement: Revisions and information on later models 13•55
8A.17B Tightening the coolant pump bolts8A.17A Fitting the coolant pump to the
999 cc engineFig. 13.28 Sectional view of the coolant
pump on the 999 and 1108 cc engines
(Sec 8A)
8C.9 Cylinder block drain plug8C.8 Bottom hose connection to the
radiator8B.4 Topping up the expansion tank with
antifreeze on the 1301 cc engine
13

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

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

PART D:
BOSCH MONO-JETRONIC
FUEL INJECTION SYSTEM
Warning: Refer to the beginning
of this Section before starting
any work.
Description
1The Bosch Mono-Jetronic fuel injection
system fitted to the 1372 cc ie engine and
later 999/1108 ‘FIRE’ models is an electroni-
cally-controlled single point injection (SPi)
system. The SPi system is a compromise
between a conventional carburettor fuel
supply system and a multi-point fuel injection
(MPi) system.
2Compared with a conventional carburettor,
the SPi unit is a relatively simple device. Fuel
is pumped to the SPi unit and then injected
into the inlet system by a single solenoid valve
(fuel injector), mounted centrally on top of the
unit. The injector is energised by an electrical
signal sent from the electronic control unit
(ECU), at which point the injector pintle is
lifted from its seat and atomised fuel is
delivered into the inlet manifold under
pressure. The electrical signals take two forms
of current; a high current to open the injector
and a low current to hold it open for the
duration required. At idle speed the injector
is pulsed at every other intake stroke rather
than with every stroke as during normal
operation.
3The air-to-fuel mixture ratio is regulated by
values obtained from the ignition coil (engine
speed), engine coolant temperature sensor,
throttle position switch, and the Lambda
sensor in the exhaust system. No adjustments
to the fuel mixture are possible.
4The throttle position switch enables the
ECU to compute both throttle position and its
rate of change. Extra fuel can then be
provided for acceleration when the throttle is
suddenly opened. Throttle position
information, together with the idle tracking
switch, provide the ECU with the closed
throttle position information.
5The 1372 cc ie system layout and principal
components are shown in Figs. 13.44 and13.45. Note that the Digiplex 2 electronic
ignition, is not fitted to FIRE models
(999/1108 cc).
6The fuel system pump is immersed in the
fuel tank and forms a combined unit with the
fuel level sender unit. A cartridge type in-line
fuel filter is fitted to the fuel line, and is located
in the engine compartment.
7The fuel pressure in the system is
controlled by a mechanical diaphragmregulator in the injection unit turret. High
pressure in the system causes the diaphragm
to operate and excess fuel is returned to the
fuel tank.
8The air intake temperature and volume is
regulated to ensure the correct mixture ratio
under all operating conditions. The
temperature of the air passing through the
injection unit is measured by a sensor which
transmits such information to the ECU for the
Supplement: Revisions and information on later models 13•73
9C.101 Fuel tank anti-blow-back
compartment (arrowed)9C.99D Throttle cable balljoint retaining
spring clip (arrowed)9C.99C Throttle cable nipple (arrowed) in
throttle linkage cut-out
Fig. 13.44 Bosch Mono-Jetronic fuel injection system components and layout on the
1372 cc ie engine (Sec 9D)
1 Fuel pump relay
2 Injection system relay
3 Fuel pump fuse
4 Ignition coil
5 Digiplex 2 ECU
6 Battery
7 Idle speed check actuator
8 Injector connector9 Fuel pressure regulator
10 Injector
11 Throttle position switch
12 Ignition switch
13 Coolant temperature
sensor
14 Engine speed and TDC
sensor15 Secondary fuel filter
16 Fuel supply pipe
17 Fuel return pipe
18 Diagnostic socket
19 Fuel injection ECU
20 Fuel pump/level sender
unit13