Friday, February 28, 2014

Air Flow Potentiometer Alternative Replacement

I am starting a project to replace the ancient air flow potentiometer that is present in most KE-Jetronic  (CIS-E) driven engines such as the ones present in pre-1991 W124s, W201, W126 etc.

This potentiometer is one of the most critical component of the KE Jetronic air-fuel metering system and it cannot be repaired. Bosch is said to have stopped the production of this item and whatever remaining stock out in the world is getting scarce.

To replace it with another old unit salvaged from another vehicle would be like swapping time bombs.

Hence this project to R&D a suitable replacement.

Modern electronics will be used to provide the same output as the air flow potentiometer that measures the swing of the air flap, which tells the KE Jetronic ECU how much air is entering the throttle body.

Air Flow Potentiometer with worn out tracks

The 3 pins of the existing potentiometer is namely the ground(0 volts), voltage supply(+5 volts) and the output voltage ( between 0.5v to slighly below 5v ) to tell the KE control unit what is the air flow.

We hope to garner as much interest, to KE(CIS-E) driven car owners, as possible and also to find out more if there were other efforts from other groups of enthusiasts around the world that had embarked on the similar project and would like to know their experience encountered during the design of this replacement air flow measuring sensor.

I can be reached at