replaced actuator and still rough idle and hesitation!
 

Last time I posted on here I indicated that our 93 300E 2.8 had a bad water pump, but that was replaced and thanks to a couple of people who helped on here guide me to the removal :) Prior to that I had posted that the idle would fluctuate and that a possible harness was the blame.. After taking it to the shop, the harness checked out, but the actuator was shot.

We replaced the actuator with one off a similar mercedes 2.8 motor in the wrecking yard. It was fine for a while until a week later the car would hesitate in reverse and drive at a full stop and idle would drop below 600 RPM and cause loping and sluggishness. Then, all of a sudden it would shoot back up to normal and do it again at the next stop... :confused: Is there an idle stabilizer on this car that needs replacing or is shot? The car has about 127,000 miles on it now. I'm hoping to cure this problem ASAP

*bump*

I've got the exact same problem on the exact same car - 93 300e 2.8. I've tried replacing a bunch of stuff, the current suspected culprit is the air mass sensor. Have you tried replacing that yet? Check on previous posts for discussion on this.... there have been a bunch.