This is actually on a 2000 mercury sable but i figured the engines would be the same or similiar at the least. It has the 3.0 24 valve DOHC duratec motor. It usually takes about 4 seconds of cranking to start and recently on warmer days, it will surge rpms on idle then fall to around 200 RPM and sometimes die. Would this be an IAC problem, vacuum leak, MAF sensor(no oiled filters)??? It only seems to die when the engine is warm and its atleast 70 or 80 degrees out.