1986 Porsche 944 Hard starting in cold weather

Please note my vehicle is actually a 1985.5 (same as '86) I have a very difficult time getting the car to start and to stay running when the engine is cold and the ambient outside temp is below 55-60 degrees. (the colder it is, the harder it is to start, no problem with cranking) This problem does not exist to any significant degree after the engine warms up (regardless of outside temp) or when the engine is cold and the outside temp is above 60-65 degrees. The only way to start the car when engine / outside temp are cold is to keep cranking the engine several times for several minutes, and sometimes pumping the gas pedal or pushing it all the way to the floor seems to be only way to get it to start. Once it is started it will run rough or stall out unless the gas pedal is depressed to maintain engine rpms above 2-2.5K for a 2-3 minutes until the engine begins to warm a little, then the gas pedal can be let off and it will idle smoothly on its own. Please Help, have already replaced DME, spark plus and wires are fairly new as well. Thanks