Loss of power

[Tony22]

Hi folks,

I have a 1994 E220 estate (just had a full service with new ignition leads) with 150K on the clock that has just started causing me a series of problems that may or may not be related:
1) Low tick over (500-600rpm) – not able to adjust!
2) Noise coming from front exhaust area – no apparent hole!
3) Car will stall at junctions when cold (automatic!)
4) Loss of power – difficult to get more than 40 mph up-hill and 60 mph on flat!
5) When warm the car jumps when the accelerator is pressed or depressed – the engine rpm jumps or looses 200 rpm!
Not sure, what the problem is and the local garage hasn’t been able to sort out the issue or increase the tick over speed. I have been told it may be related to the following:
1) Catalytic converter may have collapsed and is choking the engine!
2) Engine air inlet valve sticking or actuator broken!
3) Fuel pump and or fuel pump relay faulty!

Before I start replacing some expensive parts, what do you think is the more likely cause? Should I take it to a main dealer or other specialist? Is it worth repairing or is it time to change?

 

[jberks]

all items listed are too expensive to swap on the off-chance.
Take it to a decent MB specialist. They should be able to figure it in an hour or two and in my opinion that's £40-80 well spent. They will also probably have spare bits on the shelf or able to pull one off another car to test (except cat probably) so you'll know for definite before buying a part. Saved myself £400 on replacing a perfectly ok thorttle actuator by this method.
Unless you've won the lottery, avoid the dealer!

 

[Tony22]

power update

Have removed catalytic convertor and changed the engine temperature probe. This has restored power to engine! However, I still appear to a problem with low tick over and the car stalls when cold (sometimes when warm but usually only during the first few minutes before it settles down!). Also engine still appears to jump or loose 100rpm when you touch the accelerator.

What to try next?

Any ideas??

Regards

Tony

 

[television]

Check the overvoltage relay, 2 terminals numbered 87 should have 12volts on them, if one is down to 7.5 volts this will effect the cold idle, one of the most common faults.
Another easy fault is the EGR valve that can cause the engine to stall.
this valve should be closed at idle, what happens is that they get coked up indide and the spring gets weak, do not try and clean, its not worth it.
when they fail they stick just open, and that gives the problem.

Malcolm