Ford Repair: 1995 windstar engine stalling while driving, 1995 ford windstar, ford windstar

Question
Each weekday for the past 3 1/2 weeks while driving my 1995 Ford Windstar for a 14 mile roundtrip at between 25 and 35 miles per hour that takes me 45 minutes due to it being mostly residential areas with alot of stops, turns and speed humps; my engine stalls without notice at a different point along the way; at between 5 and 40 minutes after I've started driving. It would always start right back up after pulling off and putting it in park and turning the key to off. (It wouldn't start in nuetral or until you turned key to off.) After the first week it stalled back to back a couple of times, but would start up and i'd finish out my trip. At the end of week 3 I had a computer scan done at a shop for $39.99.($42.55) The guy said there was 1 code that came up but that it had to do with the transmission and that it wasn't what was causing my problem. Here is what was written on my reciept: D.T.C. P1780 Transmission control switch circuit out of range. (What does that mean?) and at the bottom was written: Coil pack may be shorting after heating up? Vehicle was not stalling often enough to make sure. A friend of mine who is not a mechanic helped me out by buying an ignition coil at Auto Zone for $59.99 ($63.88) and I watched him change it out, which was really simple. It didn't fix the problem as it continued stalling as it had been. On the 3rd day of that 4th week when it stalled it took about 5 minutes before it would start back up. I brought it home and parked it and haven't driven it for 2 days now. What do you think? I recently had to replace the alternator and negatine battery cable end and the battery. About a year ago I had the gas tank replaced due to a crack/leak. The weekend prior to it starting to stall I drove it to the beach which is about 65 miles away on Friday night and back 65 miles on Sunday night with no issues!  

Answer
That transmission code could be the fault of the tech who did the test. All it refers to is the Overdrive button on the shift lever not being cycled during the test. Could be wiring problem , but far as I know has nothing to do with the stalling.

The problem could be any number of things. Fuel pump, igniton, electrical. Based on your description I would be curious to see what happens to the fuel pressure when the engine dies. I believe anything else would set a code. The fuel pump might have a bad spot in it that reacts to bumps in the road or something like that. Does it make any difference where the fuel level is?

Without getting my hands on the vehicle or a code I can't tell you much more. Intermittent problems are usually the hardest to pin down to a cause.