Hello ,
The CE light is ON in my 93 190e. I ran a diagnostic and got 4 blinks - meaning Air Flow position sensor. The research in this forum suggested replacing the pot on the AFM. So removed the old one and I was surprised to find that it was in great shape ...very very slight wear. Since i bought a new pot I went ahead and replaced it. Grounded pin 3 and measured voltage on pin2 with a multimeter.

Reading showed 0.00. Started the engine, the same behavior as the old one....cold start...starts 1st time idles @800 and slowly goes up to 1000-1100 rpm. When the engine is hot it wont start the first time, takes a second or third try with me holding the gas pedal down slightly.

Reset CE light. CE comes back on after engine idles for about 45 seconds.

Now removed the new pot and put back the old pot. Unable to get any voltage from pin 2 on the pot. Same idle behavior. Any ideas. Please advise. Thanks

smk_texas
98 s420
93 190e