Air Leakage, Throttle Switch, Idle Speed

1. Check the induction system for leakage. If air leaks from point where air mass meter is mounted on engine, air-fuel mixture will be lean. Check the inlet system between air mass meter and intake manifold. Check all the hose and connections on the intake manifold. Check the couplings and seals for intake manifold, throttle housing, etc.
2. Check the throttle housing for dirt. To clean the throttle housing, disconnect the connector from the throttle switch. Remove throttle housing and clean it with a suitable solvent. Keep throttle switch dry. Remember that a dirty throttle housing indicates a blocked, incorrectly fitted or damaged air fitler.
3. Install the throttle housing. Use a new gasket. Connect hoses and throttle switch connector.
4. Adjust the throttle by loosening the screws at throttle valve switch and loosen the lock nut. Unscrew the adjustment screw until throttle is fully closed. Screw in the adjustment screw until it just contacts link arm and then a further 1/2 turn. Retighten the nut, making sure that the adjustment screw does not turn at the same time.
5. Check the throttle switch. Open the throttle slightly and listen. A click should be heard as soon as the throttle is opened to indicated that the idle switch opens. To adjust the throttle switch, loosen the screws (Allen key 3mm). Turn switch clockwise slightly, then turn switch back until a click is heard. Tighten retaining screws. Check setting.
6. Check the idle speed.

Connect a tachometer. Ground the blue-white wire from test point to close air control valve.

Ajdust engine speed w/idle adjustment screw at 700 RPM. Disconnect ground wire from test point. Engine speed should increas to 750 +/- 20 RPM.

Adjust engine controls. See THROTTLE VALVE, SWITCH, LINKAGE ADJUSTING.