1983 FIAT UNO sensor

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

20Release the retaining clip and detach the
wiring connector from the fuel injector
connection (photo).
21Loosen off the front wheel bolts each
side, then raise and support the car at the
front end on axle stands. When raised,
support at a height which will allow the engine
and transmission to be withdrawn from the
underside when fully disconnected. Ensure
that the vehicle is securely supported before
working underneath it.
22Unscrew the wheel bolts and remove the
front roadwheels.
23Release the retaining clips and remove
the underwing shield from the right- and
left-hand front wheel arch.24Relieve the staking, then unscrew and
remove the front hub nut using a socket and
suitable extension. Repeat the procedure on
the opposite front hub.
25Unscrew the retaining nut and disconnect
the tie-rod to steering arm balljoint using a
suitable balljoint separator tool. Repeat the
procedure on the other side.
26Note the direction of fitting, then unscrew
and remove the hub-to-strut retaining bolts
and nuts on each side.
27Unscrew and remove the anti-roll bar-
to-track control arm retaining nuts each side.
28Unscrew and remove the front brake
caliper hydraulic pipe support bracket bolt
each side.29Pull the wheel hub outwards and detach
the driveshaft from it, noting that there may be
a small amount of oil spillage as it is
withdrawn. Repeat the procedure on the
opposite side.
30Disconnect the wiring connector from the
engine oil level sensor lead.
31Unscrew the retaining nuts to detach and
remove the exhaust pipe front section or
alternatively, remove the system complete.
32Unscrew the knurled retaining nut and
detach the speedometer cable from the
transmission (photo).
33Unscrew the retaining nut and detach the
earth strap from the transmission (photo).
34Extract the split pin and detach the gear
selector rod from the transmission pin.
Disconnect the gear engagement and selector
levers from the balljoints.
35The weight of the engine will now need to
be supported from above. Connect a suitable
lift hoist and sling to the engine. When
securely connected, take the weight of the
engine/transmission unit so that the tension is
relieved from the mountings.
36Unscrew and remove the engine and
transmission support mounting bolts at the
points indicated (photos).
37The engine/transmission unit should now
be ready for removal from the vehicle. Check
that all of the associated connections and
13•50 Supplement: Revisions and information on later models
Fig. 13.22 The underwing
shield retaining clips (arrowed)
on the 1372 cc ie and Turbo ie
engines (Sec 7C)Fig. 13.25 Gear engagement
and selector lever balljoints
(arrowed) on the 1372 cc ie and
Turbo ie engines (Sec 7C)Fig. 13.23 Engine oil level
sensor wiring connector
(arrowed) on the 1372 cc ie and
Turbo ie engines (Sec 7C)Fig. 13.24 Disconnect the gear
selector rod at the connection
indicated on the 1372 cc ie and
Turbo ie engines (Sec 7C)
7C.33 Disconnect the transmission earth
strap7C.32 Disconnecting the speedometer
drive cable from the transmission7C.20 Fuel injector wiring connection
7C.36B Transmission rear mounting7C.36A Engine right-hand mounting

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

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

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

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

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

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