Need Help 1984-380SL Stalls/Quits

[jim16671836]

I have a friend that has a 1984-380SL that runs like a top and when the cars slows down to a stop or driving slow will idle at 12-1500 rpm. Then if the engine is shut down and you leave the car set for awhile and then when you return the engine will start and after driving for a couple blocks the engine will stall/shut down. Wait until the engine cools and it will restart and can be driven for hours. But the stall can be anywhere, on any highway...
thanks for any help... jim