I just changed the head gasket in my 1980 240dl and after starting it up, found the idle to be at about 3-4000 rpm. The idle control has no effect. After running for a minute or two, the engine warms up and begins to idle down untill the engine stalls out. Judging by the smell, my fuel distributor is pumping way too much gas into the engine with little or no air. My best guess is that I have a bad controll pressure regulator that is letting the plunger in the distributor come all the way open by not letting any pressure to it. My second guess is that the pressure regulators in the distributor itself are bad. Or perhaps an injector is stuck open. Any suggestions would be very much appreciated for I have been stumped on this for a while. Thanks a bunch.