Surging Engine

[Kenl]

My 1995 C200 pulls unevenly especially when accelerating. It seems to accelerate well enough but the rate of acceleration slows down and then picks up, almost as if it is getting choked and then clears. It's not particularly prominent but its there. You can even see the tacho hesitate slightly. If you hold the engine at steady revs in neutral or park the tacho wil slowly move up and down over a 100rpm range.

Any one got any ideas?

Thanks,

Ken

 

[sym]

My 1995 C200 pulls unevenly especially when accelerating. It seems to accelerate well enough but the rate of acceleration slows down and then picks up, almost as if it is getting choked and then clears. It's not particularly prominent but its there. You can even see the tacho hesitate slightly. If you hold the engine at steady revs in neutral or park the tacho wil slowly move up and down over a 100rpm range.

Any one got any ideas?

Thanks,

Ken

Coupled with your other problem . . . could be a faulty ECU - these things are known to have problems. Or maybe a Pedal Value Sensor (do a search - this is well documented)

S.

 

[jimmy]

When was it last serviced and the spark plugs changed?

Several of us here have experience of dealer services not including the spark plugs when they should.

 

[Kinky]

I'd second checking the plugs.

What happens when it's idling?

K

 

[Steve_Perry]

Other ideas that occured to me: MAS? Lambda Sensor? fuel injectors? spark plugs? pedal value sensor? ECU?

I'm not sure but I think that the '95 C Class would not be fitted with a MAS or a pedal value sensor. I'm sure someone else will confirm if this is correct or not.

S.

 

[Satch]

Idle air bypass valve or something in the throttle body sticking? They get cruddy over time.

 

[Kenl]

Thanks. I'll change the plugs first. I've only had the car 3 months and I don't know when they were changed.

It does the same when its idling.

I'll keep you posted on what the problem turns out to be.

Cheers,

ken

 

[Kinky]

If it's doing the same when idling - then I might suggest the idle control valve.

K