With the cold weather here again in PA I have more information on the hard starting of my wife's '85 635csi. Last week when it was 60F outside the cold start was no problem. After the car warmed up all subsequent starts required 5 secs. or more of cranking. This never got any better as long as the car was hot. Today I noticed that again the cold start was OK but with outside temps at 30F all hot starts were instantaneous with no cranking. I have a sensor problem , I assume, but which one?? Any and all advice is appreciated,