i have a 93 300e 2.8.... the car starts and sometimes runs normal for a minute and then starts to loose and gain rpms constintly and does not stop at all.....and as soon as you put the car in gear the car automatically stalls, it does that everytime you put it in gear... it only moves if the gas pedel is pressed with the brake and then moved to gear only then it will move but as soon as the gas pedel is released the car stalls!!!! any one have a clue what the problem might be?

 

you got no idle.

clean idle speed air valve.

 

could have a few problems i speed control valve. air flow sensor, purge valve, really hard to tell with out taking a look at it and doing some tests