1993, 230E, Automatic, Factory Air, fuel Injected, after running for a couple hours, even in super slow traffic, AC blowing nice and cold. You shut off the car to do some shopping and when you return 5 minutes later the car starts right up but wont idle, you have to use 2 feet to keep the car running. Holding the Idle at 1000, with one foot and brake with the other you can drive off and within 5 or 10 minutes it will return back to normal 700/800 RPM like nothing ever happened.
When you do start it hot, it revs quicky and sound good, just wont idle, watching the tach, when reving it backs down to about 1500 pause, then 700 pause, then 500 slight pause , then off.
Under normal conditions, the 1500, 700, then steady at 700, with or without the AC on. With AC the RPM might be more like 800-850.
Must remember we get most of our fuel from drums, worst possible condition for fuel injection!