Funnest thing!? 2003 Windstar runs excellent, gives no codes when ENGINE stops. First it would do once or twice daily, then sometimes idiling for a few minutes, now it will run for a few seconds or travel 50 feet. I have Replaced all Cam, Crank sensors and Distributor parts. Every time it dies I find no codes, and each time when I attempt to (start) restart, no spark. Later, 1 hour, 5 hours or maybe 2 days, this old windstar decides it will spark, and then it will run fine for maybe 50 feet, THEN AGAIN dies = no spark (The cycle will repeat if I am insane enough). There are never any codes, or lights or fuel problems, it is always (via checking spark from wires) fails to spark until it decides it wants to. ANY IDEAS as this is not funny anymore pushing it home from down the block?!
The secondary high voltage system is not monitored by the computer, so I would start looking there. I don't know if you have coil packs, or a distributor. If you have a distributor, I would double check the cap and rotor, the main wire from the coil and the coil itself and it's wiring. Look for any green corrosion that may short the spark out when it's damp outside. If you have a coil pack, it would be unusual for all the coils to go bad at the same time, but look for wiring problems to the coils and the circuit board underneath the coil.