Adjusting the idle on a 1.8lt injected engine

Adjusting the idle on a 1.8lt injected engine

This applies to the 1.8lt JH injected engine. The idle adjustment screw is located at the top of the throttle body, facing towards the cabin of the car.

You can turn this by hand, either way, to adjust the idle speed. Note, that if the engine has been running this area of the car may be hot.

A common problem to be aware of is the rubber O ring the adjustment screw sits in could be worn or have disintgrated which may affect the idle.

If you are having issue with idle fluctuating check electric ground points are clean, Idle Air Control valve is working correctly and air/fuel mixture is adjusted correctly.

Mk1 Golf engine idle speed screw location


Idle adjustment screw

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