I have a 2000 cougar 2.5L and had what sounds like the same problem and probably did it to myself. I was down to about one gallon in the tank and was gassing it hard going through a turn and it stumbled bad, fuel pump sucking air. In the month or so since then it would start to fail at 4 to 5 thousand RPM, at first only in second gear, (figure that one out) then more and more in other gears where it would just float with no accelleration. finally, it would die like you turned off the key if you floored it at that RPM. This was always with less than 1/4 tank of fuel. I diagnosed it myself searching the forum here, then asked my dealer (Excellent dealer in Danville, PA) and he said he had seen it before, and that it made them crazy the first time they had seen it. I was lucky, Car still under warranty at 30,000 miles. A new fuel pump fixed me right up, and this is what you need almost guaranteed, I think pumps are about $160, and on a Contour, you don't have to drop the tank, unlike my Cougar.
This happens when hot and cold...not every single time but very often....thanks for any info....
