Contents - Volkspage

4A.4 Fuel system: single-point injection models
5.12 Exploded view of the throttle
body upper section and fuel injector
1 Injector retaining screw
2 Protective cap
3 Injector retaining cap with integral
inlet air temperature sensor
4 O-ring
5 injector
6 Fuel pressure regulator
7 Throttle body casting
8 Gasket
9 Fuel supply hose
10 Banjo bolt
11 Sealing washers
10 Refer to Section 9 and depressurlse the
fuel system, then disconnect the battery
negative cable and position it away from the
terminal.
11 Unplug the wiring harness from the
injector at the connector(s), labelling them to
aid correct refitting later.
12 Remove the screw and lift off the injector
retaining cap/inlet air temperature sensor
housing (see illustration)
13 Lift the injector out of the throttle body,
recovering the O-ring seals. Check the
injector electrical resistance using a
multimeter and compare the result with the
Specifications .
Refitting
14 Refit the injector by following the removal
procedure in reverse, renewing all O-ring
seals. Tighten the retaining screw to the
specified torque.
Inlet air temperature sensor
15 The inlet air temperature sensor is an
integral part of the fuel injector retaining cap.
Removal is as described in the previous sub-
Section. Its electrical resistance may be
checked using a multimeter (refer to
illustration 5.12).
Fuel pressure regulator
16 The fuel pressure regulator components
are matched to the upper section of the
throttle body and can only be renewed as part
of a complete assembly.
Throttle valve positioning module
Removal
17 Disconnect the battery negative cable and
position it away from the terminal. Remove
the air cleaner/throttle body air box, with
reference to Section 2.
18 Refer to Section 4 and disconnect the
accelerator cable from the throttle body.
19 Unplug the connector from the side of the
throttle valve positioning module.
20 Remove the retaining screws and lift the
module together with the accelerator cable
outer mounting bracket away from the throttle
body.
Refitting
21 Refitting is a reversal of removal. Check
that the idle switch plunger lines up with the
plastic stop on the lower section of the
throttle body. If necessary, adjust the position
of the throttle valve positioning module
bracket after loosening the mounting screws.
Throttle valve potentiometer
22 Refer to the relevant sub-Section and
remove the throttle body. The throttle valve
potentiometer is an integral part of the lower
section of the throttle body and cannot be
renewed separately.
Idle switch
23 Refer to the relevant sub-Section and
remove the throttle valve positioning module.
The idle switch is an integral part of the
module and cannot be renewed separately.
5.30 Two coolant temperature sensors are
fitted; the one colour-coded blue (arrowed)
serves the engine management system
Lambda sensor
Removal
24 The lambda sensor is threaded into the
exhaust pipe, at the front of the catalyst.
25 Disconnect the battery negative cable and
position it away from the terminal, then unplug
the wiring harness from the lambda sensor at
the connector, located at the rear of the
engine, beneath the throttle body.
26 Note: As a flying lead remains connected
to the sensor after is has been disconnected,
if the correct size spanner is not available, a
slotted socket will be required to remove the
sensor. Working under the vehicle, slacken
and withdraw the sensor, taking care to avoid
damaging the sensor probe as it is removed.
Refitting
27 Apply a little anti-seize grease to the
sensor threads - take care to avoid
contaminating the probe tip.
28 Refit the sensor to its housing, tightening
it to the correct torque. Restore the harness
connection.
Coolant temperature sensor
Removal
29 Disconnect the battery negative cable and
position it away from the terminal, then refer
to Chapter 3 and drain approximately one
quarter of the coolant from the engine.
30 The temperature sensor is located on the
left hand side of the cylinder head, under the
heater coolant outlet elbow (see illustration).
There are two sensors fitted; the one colour
coded blue serves the engine management
system, the black one produces a signal for
the instrument panel temperature gauge.
31 Unplug the wiring harness from the sensor
at the connector, then extract the clip and lift
the sensor from its housing, recovering the O-
ring - be prepared for an amount of coolant
loss.
Refitting
32 Refit the sensor by reversing the removal
procedure, using a new O-ring. Refer to
Chapter 1 and top-up the cooling system.