I've got a suspicion that the ECU or PCM or whatever you call that thing has a mind of its own. I think it's possessed, and at times it says " ". It seems that a lot of these intermittent problems can be resolved (on a short term basis) by resetting the ECU.

95 Contour Zetec, ATX (wrecked, sitting in the barn) 95 Mystique Zetec, MTX 2000 Taurus SEL 3.0L Duratec 1994 Crown Victoria LX 4.6 V8 1993 Chevy Silverado 4.3 V6