Air Flow Sensor Plate Position Sensor: Service and Repair

- remove air shroud (arrows)





- detach and remove mixture control unit completely from air filter housing.





- disconnect potentiometer from wiring connector (arrow)





- loosen potentiometer mounting screws (arrows), carefully remove potentiometer from sensor body

NOTE: Do not touch contact surfaces of the potentiometers and/or the contact tabs in the air distributor.

- install new potentiometer and adjust


Adjustment - To Be Performed Only After Replacing Potentiometer





- with air shroud removed, turn and lift adjusting screw 1 and slide 2 into upper (full throttle) position on VW 1348/1.
- Place VW 1348/1 centrally on edge of air flow sensor assembly
- pointer 3 faces to center of fuel distributor
- push adjusting slide 2 down onto stop
- turn setting screw 1 clockwise until magnetic end contacts air flow sensor plate retaining bolt (with air flow sensor plate in rest position)





- connect harness VW 1501 between potentiometer and terminal
- connect voltmeter to contacts 2 and 3 of the harness connector
- mount the mixture control unit in such a way that the air flow sensor plate moves freely.





- switch ON ignition
- pull slide 2 of adjusting device into the 1st detent (idle position)
^ specification: 0.2 to 0.5 volts

If specification NOT obtained:
- loosen mounting bolts on potentiometer
- move sensor, in slot until the specification is obtained
- retighten mounting bolts
^ specification: 0.2 to 0.5 volts

If the specification is still NOT obtained replace air distributor.





- pull slide 2 of adjusting device into the 2nd detent (Full throttle position)
^ specification: 4.0 to 4.5 volts

If specification NOT obtained:
- repeat test in idle position and/or repeat basic adjustment of potentiometer

If specification OK
- push slide 2 of adjusting device down completely (rest position of sensor plate)
^ specification: 0.0 volts

If specification NOT obtained:
- repeat lest in idle and full throttle positions

If specifications still NOT obtained after repeated adjustments
- replace air distributor

If specifications OK
- seal mounting screws with paint