Engine problem...need help here...?

1991 Chrysler LeBaron 6cyl. EFI. When engine is cold it runs rough and will occasionally stall. The engine RPMs sometimes Fluctuate from 200 to 1200 until it evens out. When the engine finally warms up, the car runs great. I have replaced all the Vacuum lines that i can find. New cap/rotor and PCV valve. ANY ideas?