my 500sel wont run below 800rpm, runs very poorly below 1500rpm, and stalls a lot.

saw today that there is no belt to run the air pump/ smog pump. could this be related?

 

nope your car is running high idle for a reason either it needs a lambda (running lean) adjustment or it needs a idle speed valve and idle speed control unit or a little of both. what i have seen alot of with 117 motors over 100k is the intake manifold rubber seals leaking.

 

thanks for the tips.

a couple of questions though

first, is there any way to test the manifold gaskets like a sprayer bottle or something?

also, where about would the adjustment for my lambda unit be? i guess i always thought a lambda was the same thing as an o2 sensor, but this car doesnt have any, and i have heard the thing about lambda adjustment several times.

as far as the speed valve, the idle speed itself is ok, the problem is that the engine stutters and stalls. i have to hold it running or it will quit on me. it feels almost like a misfire, but i have been through the whole ignition system and most of the fuel delivery and it all is either new equipment or in good working order.

im sick of putting money into this car, but i know i cant sell it running like it does.