500SL warms up and the goes into "Limp Home Mode"
 

I have a 1990 500SL with 60K miles. I recently replaced the EHA when it was doing a similar thing. Heres the deal.. The car runs fine until it reaches 100degrees, or warms up...it then will stall at low speeds and when you restart and try to accelerate, it will only allow 2500RPM max,(limp home mode) however I can manipulate it to get the MHP up, (like 55mph)...when I take the foot off accelerator the RPM's immediately fall like its going to stall, seems like something electronic. Pushing the accelarator to the floor still only gets you 2500 RPM. The curious thing is It only does it after it warms up. Is this a Throttle Actuator, KE unit, Clogged Cat Converter, Airslide, potentiometer track gone bad. ASR problem? I am open to suggetions as we are stumped and my Mechanic can't pull codes with the model/year.

Thanks,
James

You have ASR on a 1990 model? Didn't know that was possible. You should have a 16 pin diagnostic connector in the engine compartment. You can build the fault code reader yourself - do a search for more info - then read pins 3 and 14, should be some clues there.

check your alternater and your battery see if your charging. happened to me it was a bad charging system.