b) Ensure that the mating surfaces of the
manifold and throttle body are clean and
dry, then fit a new gasket. Securely
tighten the throttle body retaining bolts.
c) Ensure that all hoses are correctly
reconnected and, where necessary, that
their retaining clips are securely
tightened.
d) On completion, adjust the accelerator
cable using the information given in
Section 4.
13 Fuel injection system -
testing and adjustment
3
Testing
1 If a fault appears in the fuel injection
system, first ensure that all the system wiring
connectors are securely connected and free
of corrosion. Ensure that the fault is not due to
poor maintenance; ie, check that the air
cleaner filter element is clean, the spark plugs
are in good condition and correctly gapped,
the valve clearances are correctly adjusted,
the cylinder compression pressures are
correct, the ignition timing is correct, and that
the engine breather hoses are clear and
undamaged, referring to Chapters 1, 2 and 5
for further information.
2 If these checks fail to reveal the cause of
the problem, the vehicle should be taken to a
Peugeot dealer for testing. A wiring block
connector is incorporated in the engine
management circuit, into which a special
electronic diagnostic tester can be plugged.
The connector is clipped to the rear of the
ECU mounting box. The tester will locate the
fault quickly and simply, alleviating the need
to test all the system components individually,
which is a time-consuming operation that also
carries a risk of damaging the ECU.
Adjustment
3 Experienced home mechanics with a
considerable amount of skill and equipment
(including a tachometer and an accurately
calibrated exhaust gas analyser) may be able
to check the exhaust CO level and the idle
speed. However, if these are found to be in
need of adjustment, the car must be taken to
a Peugeot dealer for further testing.
4 On the Fenix and Bosch systems, no
adjustment is possible. Should the idle speed
or exhaust gas CO level be incorrect, then a
fault must be present in the fuel injection
system.
5 On the Magneti Marelli system, it is
possible to adjust the mixture setting (exhaust
gas CO level) and ignition timing. However,
adjustments can be made only by re-
programming the ECU, using special
diagnostic equipment connected to the
system via the diagnostic connector.
14 Fenix system components -
removal and refitting
3
Throttle position sensor
1 Disconnect the battery negative lead, then
disconnect the wiring plug from the sensor.
2 Remove the two securing screws, then
carefully withdraw the sensor from the fuel
injection unit.
3 Refitting is a reversal of removal. No
adjustment of the sensor is possible. A self-
adjusting system is incorporated in the
electronic control unit.
Fuel injector
Note: Refer to the warning note in Section 1
before proceeding. If a faulty injector is
suspected, before condemning the injector, it
is worth trying the effect of one of the
proprietary injector-cleaning treatments.
4 Depressurise the fuel system with reference
to Section 8
5 Disconnect the battery negative lead.
6 Unscrew the two securing nuts, and
remove the air box from the top of the throttle
housing.
7 Release the securing clip and disconnect
the injector wiring plug.
8 Remove the screw securing the injector
retaining plate to the top of the fuel injection
unit, lift off the retainer, then withdraw the
injector.
9 Recover and discard the injector sealing
rings (check to ensure that new sealing rings
can be obtained before discarding the old
ones).
10 Refitting is a reversal of removal, bearing
in mind the following points.
a) Always renew both sealing rings, and
apply a smear of grease to each to ease
injector refitting.
b) Refit the injector so that its wiring
terminals point towards the front of the
vehicle, and locate the edge of the
retainer securely in the groove at the top
of the injector.
c) Before refitting the injector securing
screw, apply a few drops of locking fluid
to the threads.
d) On completion, switch on the ignition and
check carefully for signs of fuel leaks; if
any signs of leakage are detected, the
problem must be rectified before the
engine is started.
Idle speed control valve
11 Disconnect the battery negative lead, then
release the securing clip, and disconnect the
wiring plug from the valve.
12 Loosen the clamps, and disconnect the
two air hoses from the base of the valve,
noting their locations in relation to the flow
direction arrow marked on the valve body.
13 Loosen the two clamp nuts or bolts (as
applicable), then withdraw the valve (it may be
necessary to remove the clamp completely, to
provide sufficient clearance to remove the
valve).
14 Refitting is a reversal of removal, ensuring
that the valve is positioned correctly, with the
air hoses connected as noted before removal.
Fuel pressure regulator
15 The fuel pressure regulator (consisting of
a valve operated by a spring-loaded
diaphragm and a metal cover) is secured by
four screws to the top of the throttle housing.
Although the unit can be dismantled for
cleaning, if required (once the air box has
been removed for access), it should not be
disturbed unless absolutely necessary.
16 At the time of writing, it was not clear
whether the pressure regulator components
were available separately from the complete
throttle housing.
17 Always depressurise the fuel system
before disturbing any components. If the
regulator cover is removed, note its
orientation on the throttle housing before
removal, to ensure correct refitting.
Inlet air temperature sensor
18 The sensor is screwed into the top of the
inlet manifold.
19 Disconnect the battery negative lead.
20 Release the securing clip, and disconnect
the wiring plug from the sensor.
21 Unscrew the sensor and withdraw it.
22 Refitting is a reversal of removal.
Manifold absolute pressure
(MAP) sensor
23 The sensor is mounted on the body front
panel.
24 Disconnect the battery negative lead, then
release the securing clip and disconnect the
wiring plug from the sensor.
25 Disconnect the vacuum hose from the
sensor.
26 Unscrew the two securing nuts, or bolts
(as applicable), then withdraw the sensor from
the body front panel.
27 Refitting is a reversal of removal.
Coolant temperature sensor
28 Disconnect the electrical plug from the
sensor on the water housing.
29 Drain the cooling system as described in
Chapter 1.
30 Unscrew the sensor from the water
housing.
31 Refit in the reverse order using a new
sealing washer, then top-up and bleed the
cooling system with reference to Chapter 1.
Engine speed/position sensor
32 Disconnect the wiring lead and release it
from the clips.
33 Unscrew the bolt and withdraw the sensor
from the engine.
34 Refitting is a reversal of removal. It is not
possible to adjust the position of the sensor.
4B•6 Fuel/exhaust systems - single-point fuel injection models