1987 Mercedes Benz 560sel idle

Sounds like to me you have a problem with the cold idle air regulator. It is located on top, center, front of the engine. Dead center about a foot in from the radiator. It is a cylinder about 2 inches around and 6 inches long it injects air directly into the intake. One end is inside a elbow hose going into the intake just in front of the throttle body and has a side hose also with a 2 inch vac hose connecting both hoses in a y shape. The other end has a plug on it and once unplugged you will see two prongs. Part is under breather pan, you will need to remove this first. All you need is a 10 mm socket and ratchet. Start engine cold and place hand on this part you should feel and hear vibration from this part. Only when engine has not warmed up. Tell me what you find out.

Rasmatazzzzz. Where is or what is the CIS-e control unit. Theres nuttin with any words or writting on or in or on the kick panel. Ive been in kemo since april(liver failure) and im just getting round to trying to get this beautiful car running right. I replaced the idle speed control unit, replaced all the vaccum hoses, I replaced the smog hoses, (what a trip that was) but instead of idling at 1100 rpms, it now starts (have to pump it a lot) and idles at 1500- 1700 rpms, until I put it in drive, then it idles at 750-600. What the H%$$ is going on. If I put it back in park or neutral, it goes back to 1500-1700rpms. If I had any money to take it to a mechanic I would. But the cost of staying alive has bankrupt me. Any ideas. First. Where is this CIS-e unit located. Lots of boxes down thar. Found out where the alarm system and the parking lights are. Please help. I have already donated money but got nuttin for it. About 6 hours of aggrevation. If I do get it fixed I will send you some money. It'll be after the first they put me on disability