Idle speed control valve - removal and refitting

Note: A new gasket must be used when refitting the valve.

2.0 litre SOHC models
1 Disconnect the battery negative lead.

2 Disconnect the idle speed control valve wiring plug by releasing the retaining clip and pulling on the plug, not the wiring (see illustration).

13.2 Disconnecting the idle speed control valve wiring plug
13.2 Disconnecting the idle speed control valve wiring plug

3 Unscrew the two retaining nuts and withdraw the valve from the inlet manifold (see illustration). Recover the gasket.

13.3 Unscrewing an idle speed control valve retaining nut
13.3 Unscrewing an idle speed control valve retaining nut

4 Clean the valve and manifold mating faces before refitting, taking care not to allow dirt to enter the manifold.

5 Refitting is a reversal of removal, using a new gasket.

6 On completion, start the engine and check that the idle speed is stable if not, check for air leaks around the valve. Switch on all available electrical loads and check that the idle speed is maintained - if not, suspect a faulty valve.

2.0 litre DOHC models
7 Disconnect the battery negative lead.

8 Loosen the securing clip, and disconnect the air inlet hose from the throttle body.

9 Unscrew the securing nut, and release the air inlet tube from the bracket on the engine compartment front panel.

10 Disconnect the wiring plug from the idle speed control valve.

11 Release the air cleaner lid securing clips then remove the air inlet tube, plenum chamber, and air cleaner lid as an assembly, disconnecting the breather hose from the air inlet tube.

12 Unscrew the two securing bolts, and withdraw the valve from the air inlet tube.

Recover the gasket (see illustration).

13.12 Withdrawing the idle speed control valve and gasket
13.12 Withdrawing the idle speed control valve and gasket

13 Clean the valve and air inlet tube mating faces before refitting, taking care not to allow dirt to enter the air inlet tube.

14 Refitting is a reversal of removal, using a new gasket.

15 On completion, start the engine and check that the idle speed is stable if not, check for air leaks around the valve. Switch on all available electrical loads, and check that the idle speed is maintained - if not, suspect a faulty valve.

Mixture adjustment potentiometer (2.0 litre DOHC) - removal and refitting

1 The potentiometer is located at the rear right-hand side of the engine compartment, behind the MAP sensor.

2 Disconnect the battery negative lead.

3 Remove the screw, then withdraw the potentiometer and disconnect the wiring plug.

4 Refitting is a reversal of removal.

    See also:

    Instrument panel components - removal and refitting
    1 Remove the instrument panel. Panel illumination and warning lamp bulbs 2 Twist the relevant bulbholder anticlockwise and withdraw it from the printed circuit board on the rear of the instrument ...

    Cylinder head - removal and refitting (engine removed)
    Note: Up to early 1984, splined type cylinder head bolts were used, and from early 1984, size T55 Torx bolts were used. Torx type bolts must always be renewed after slackening. The two types of bo ...

    Air cleaner - removal and refitting
    Removal 1 On CVH models, disconnect the battery negative lead. 2 Remove the screws from the top of the air cleaner cover (see illustration). 3.2 Air cleaner securing screws (arrowed) 3 Disconn ...