Checking the idle shut-off valve of Keihin carburetors (Audi 80 B3)

The idle cut-off valve closes the supply of idle fuel mixture and additional mixture to the mixing chamber when the ignition is switched off. This prevents the engine from running due to pre-ignition. If the valve is faulty, the engine will not start.

Examination

Turn on the ignition.

Disconnect and connect the plug connection of the idle speed cut-off valve several times. The valve should click.

Otherwise, check the reliability of the connection and contact of the ground cable between the carburetor and the cylinder head cover.

Connect the valve connector with the auxiliary wire to the (+) battery. The valve should click.

Otherwise, unscrew the bolt and remove the valve. Check the ground contact to the carburetor, otherwise replace the valve.

(The text is based on materials from the website «AudiManual»)