hello! i have a 84 500se and i would very greateful if someone could give me some advice. My problem is that my car starts fine but it has no power
when the car is cold and i try to rev the engine it hesitates instead of
accelerate, when it warms up the engine revs up and down and fuel pump
makes sound as if it is over working -------what could it be?


Thank you

ahh, more problems with the 126's idle...

I'm on the same Boat.


I'm about to replace:
-O2 sensor
-Voltage Regulater

What I've tried sofar:
-Resoldering the ICU
-Cleaning the AirSlideVale/IdleControlValve
-Overvoltage protection relay

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-1983 VW Rabbit LS Diesel (5speed, VNT/Giles build)

would that be related with fuel pump would make alot of noise
what do you think?

I recently ran into a 78 slc with similar symptoms. The catalytic converter was toast and needed to be repalced. Excessive exhaust backpressure was the tipoff on the converter. After fixing the one problem the car still ran without power. Replacing the fuel injectors resolved the problem. The opening pressure of the CIS injectors had gotten to a point where they restricted the air into the cars engine. The air flow measuring point in the CIS injection was holding the air back because of the injectors would not open! If you are not familiar with the fuel injection system please let a shop look it over. It could also be a simple problem with the warm up regulator not doing its job. If the system control pressure is too high this can also cause the symptoms you are talking about. John

My 80 500 SE has the same problems and similar symptoms.
So you are stating to
Replace the catalytic converter.
Replacing the fuel injectors resolved the problem.
Replace the warm up regulator.
OK, where is a good Online Site to get these items?

Thanks

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Mercedes-Benz 500 Evolution

i think the second responder was onto a good idea in having it checked out. replacing all those things without knowing which are bad will be expensive and may not actually solve your problem.

not to be too obvious but have you checked your fuel filter, your fuel supply and your tank to be sure you have fuel in it that is clean and good?

you dont say ifyou just aquired the car of if this has come on gradually.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.