Checking the adjusting lever and control piston (K-, K-Jetronic, KE-Jetronic) (Audi 80 B3)

The control piston in the fuel dispenser is connected to the back-up valve. The piston opens the channel for the fuel outlet and thus determines the injection quantity. A difficult piston stroke results in the engine starting poorly, jerking in transient modes and/or not achieving maximum power.

Remove the air duct cover.

Turn on the starter or auxiliary pump control button for 10 seconds.



Raise the adjusting lever of the support flap, while the lever should move with the same resistance along the entire path.

Move the adjustment lever quickly downwards, no resistance should be felt, otherwise replace the air volume meter.

If the valve moves only up with difficulty and/or jerkily, but down easily, the control piston is stuck. Replace the fuel dispenser.

If the damper moves up and down with difficulty and/or jerks, the adjustment lever is not moving properly. Replace the air flow meter.