Hi Guys, 1st a Merry Xmas to everyone and best wishes for the New Year. I would like to ask for some help with a problem on my 1995 E220 petrol. Recently whilst stopped at traffic lights etc, engine will hiccup then run very roughly seems like running on 3 cylinders and with little to no throttle response. This will also occur when rolling downhill or other off throttle applications. Immediately turning engine off then re-starting fixes this. Sometimes this wont happen for a week or 2, yet on occasion it happens 20 times a day....then will suddenly disappear for a week or 2.

Any help would be greatly appreciated

Thanks

 

Sounds like car goes into Limp Home. This would explain rough idle and no throttle response BUT does the CEL Check Engine come on?
Have you accessed any DTC Diagnostic codes in the ECU?

Issue IMHO is why the car "hiccups". since this appears to trigger Limp.

A few shared thoughts.

Hiccup is characteristic of an intermittent ignition off fault BUT on the other hand.....

Are battery contacts secure and not corroded?
Do you notice dash lights / gauges move when the car hiccups?
When were the spark plugs changed. Excess gaps?
Anything else to add to symptoms / history?

 

Happy New Year to all forum members and thank you Snanceki for the reply. In answer, battery is new and of high quality, No dash light or gauge movement, plugs have about 7K klm's and I have cleaned and checked gaps...all ok. No other history to add.

No CEL (?) comes on and no diagnostic codes have been accessed. The problem is intermittent and only happens when off throttle, eg: rolling down a hill...it wont hiccup here just suddenly will start running rough...the car can be driven and will clear after sometime, or can be put in neutral and can sometimes be cleared with a few good revs, though not always. When stopped, it will suddenly kind of "buck" and will move slightly fwd, then run roughly...immediately turning engine off and re-starting cures the problem. However, it can happen many times in a few days then not happen for a week or more. It feels to me like it drops a cylinder so it running on 3...very strange

Any advice much appreciated

Thanks all

 

Anybody? Any help appreciated

Thanks