B1 - B11 Air Leakage, Throttle Switch, Idle Speed

B1 Check Intake System For Leakage
- A leakage from the air mass meter to turbocharger junction will cause too lean an air/fuel mixture, A leakage from the turbocharger to engine junction will cause too rich a mixture.




- Check all hose/pipe connections and gaskets/seals for leakage from:
- Air Mass Meter - throttle housing
- Throttle housing - intake manifold
- Idle adjustment screw housing
- Intercooler (cell structure - cooling fins)
- Intake manifold - cylinder head
- Injectors - intake manifold.

B2 Throttle Housing





- Check housing for dirt.
- Clean as required.

- Disconnect throttle switch connector.
- Remove throttle housing and clean with suitable solvent, making sure that the throttle switch is kept dry.

IMPORTANT Dirt in the throttle housing indicates a blocked, damaged or incorrectly installed air filter.

B3 Install Throttle Housing





- Install new gasket.
- Reconnect hoses and throttle switch connector.

B4 Basic Adjustment Of Throttle Shutter





- Loosen locknut.
- Unscrew adjuster screw until throttle is fully closed.
- Tighten screw until it just contacts link, and then a further 1/4 turn.
- Tighten locknut, without altering position of screw. (It is sometimes necessary to loosen the throttle switch to be able to adjust the throttle.)

B5 Check Adjustment Of Throttle Switch





- Open throttle slightly and listen.
A click should be heard as soon as the throttle opens, indicating that the idle switch has opened.

Adjustment:
- Loosen retaining screws (3 mm Allen).
- Turn switch clockwise.
- Then turn it counterclockwise until it just clicks.
- Tighten retaining screws.
- Check adjustment.

B6 Check Throttle Pulley
- Check for smooth operation of pulley.

B7 Check/Adjust Throttle Cable And Cruise Control Cable
- Both cables should be taut in idle position but not affect position of throttle pulley.





- Pulley should contact idle stop.
- Adjust cables if necessary.
- Depress accelerator to floor and check that pulley contacts full throttle stop.

B8 Check/Adjust Kick-Down Cable
- (automatic transmission)
- Depress accelerator to floor.
- NOTE: Do not operate throttle pulley by hand or setting will be incorrect.





- At full throttle, cable sleeve - clip separation should be 5O.4-52.6 mm (1.98-2.O7 in).
- Adjust if necessary.

B9 Connect/Adjust Link Rod





- Place a 1 mm (0.04 in) feeler gauge between throttle pulley and idle speed stop.
- Clearance between throttle lever and adjustment screw should be 0.1 mm (0.004 in).
- Adjust link rod if necessary.

B10 Check/Adjust Idle Speed And CO Content
Refer to Fault Tracing Steps E1-E26.

B11 Check The Idle Valve





- An arrow on side of valve indicates direction of flow.

If idle speed is far too low:
- Make sure that hoses, nipples and idle valve are not blocked by deposits from crankcase ventilation system.
- Make sure that engine oil has been changed as specified and that correct grade has been used.
- Rectify as required.

IMPORTANT! If plastic fuel line ties have been removed they must be reinstalled.