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 or a spanner, 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 that sits on adjustment screw could be worn or have disintegrated which may cause a vacuum leak and 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 on the Bosch K-Jetronic injection system.

Mk1 Golf engine idle speed screw location

 

Idle adjustment screw

First published: 17/09/17
Last updated: 17/07/22

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