Hello,

I had taken out the Air Flow Meter pot out of my 300E '86 to test my wife's 260E. But ever since I put it back it has not been working properly. I noticed this when there was high idle at start up and then RPM reducing to the point of stalling.

I checked the diagnostic plug, it shows 40% duty cycle (which indicates a problem with AFM in the manual). I also measured the voltage between pin 1,3 - it's about 4.5 V which is OK. However the voltage between pin 1,2 is close to zero. The manual says it should be around 0.5 - 0.7 Volts.

I had marked to correct position of the pot before I take it out, so it is sitting at its original position.

I am not sure what I have done to cause this malfunction but do I need to replace the whole AFM or just the pot?

Thanks.

__________________
Zorin

'88 Benz 420 SEL
'79 Porsche 911SC ('87 Carrera Engine)
'00 BMW 540 Sports Package
'99 Land Rover Discovery

86 300E - Manual (sold)
88 260E (sold)
84 944 (sold)