2002 Focus with 2.0L DOHC Zetec engine. At cold start, the engine would start, but the speed would drop and die if not stepping on the gas pedal. If I step on the pedal once and get the engine speed QUITE high, and then let go the pedal, it will run fine then, and I can drive without any other problem. I don't really need to keep it at high speed for any time, and so I don't think it's warming up issue. It always starts and runs fine when warm. I just replaced the idle air control valve yesterday, but that didn't get rid of the problem.
The old IAC valve looks suspicious to me. The whole valve stem is covered with a layer of dust. I would expect a section without dust the the valve stem moves up and down when it works. But then the new IAC valve didn't fix the problem.
Hope someone can help. Thanks.