Hello everyone.
I have a Mercedes C180 kompressor 2003 with 90700 miles with the 7.226 automatic transmission and m271.946 engine. I have this strange problem that has been bothering me for quite some time now. The car got this habit of jerking/hesitatation from time to time when accelerating at low speed, but it seldom does this at higher speed. It doesn't do this at wide open throttle either or when cruising.
It also shifts fine for the most part, maybe now and the a few times it may shift a little more noticeably than other times, but normally you dont feel it shifting. There are no trouble codes, neither are there any codes for the transmission. But i did replace a vacuum hose that was torn, there are no other vacuum leaks as far as ive seen and felt. Also when the car is in either drive or reverse, if you gently push the throttle and the take your foot off, the car almost stalls out, the rpm dips up and down rapidly between 500 - 900rpm during this time and it only does this when you lightly click on the accelerator pedal at idle in drive or reverse, not in neutral. If you combine this with hard steering when you are going to park and you lightly press on the gas, then the car will stall out.
Ive recently checked the transmission fluid lvl and its fine, ive changed the spark plugs, and airfilter too. Maybe anyone have an idea what this might be? I was thinkng maybe the torque converter may be the culprit.
Finally the long term fuel trim stays steadily at 7.8% extra fuel for some reason too.
Thanks alot for reading.
It looks like it might be the tps switch but just a guess. You need to hook up a scanner read the values your sensors give you thru out the rpm range. If their are any codes they also should be extracted and read. Unless their is a Benz tech here problems like this are not that easy to diagnose unless you have a prof scaanner and know the values in detail.
My bet is you have another vacuum leak.
thanks for the input. Ill hook up a star diagnostic tool and look at the data