The end of last summer we took our '85 LTD wagon up north on vacation. It was still reasonably hot during the trip even though it was late in the season. It is about a six hour ride back and forth.

On the way up the car ran fine as well as while we were up north. Coming back down after driving for about 2-3 hours going down the highway the car just stalled and quit (of course this is while my wife, son, dog, and MIL are in the car with all of our stuff). After doing a cursory check under the hood I didn't see anything obvious. I did have fuel at the CFI, but what pressure I do not know. The car would turn over just fine, but it wouldn't start. As any good person driving a Ford with TFI I had a spare ignition module which I installed. No dice. With the limited tools I had it appeared I wasn't getting spark. Wife and son walk to the gas station down the street while I ponder my next move. After checking a few more things I have my MIL crank the engine while I check something and it starts up (this is after about 20 minutes or so). Elated I go pick up my wife and son and we get back on the road.

Everything is going fine and then about 1 hour later the same thing happens. Pull off the road and same thing. Again after sitting for a while it starts back up. Since changing the TFI module seemingly had no effect I then focused on the coil. I located one at a parts store and swapped it out. Ran fine. After this it was getting dark and cooling down. Another two hours of driving and just as we are getting off the highway by our house it stalls again. Again same thing won't restart until sitting for a while.

Sooo, since it is hard to diagnose a problem when it is so hard to recreate I am about at the point where I am willing to just throw parts at it (as if I weren't already there). My next step was to replace the distributor pickup coil unless anyone has any other suggestions. Clearly something is getting hot, failing, cooling down, and then resumes working. Definitely sounds like an electrical component to me. Since I had fuel at the CFI (again could only check for fuel not the actual pressure) I am assuming the fuel pump(s) are okay. Yes I realize that new parts (ignition module and coil) can be bad, but changing them didn't really seem to change anything.

This engine will eventually be replaced so I don't want to go crazy, but it needs to provide a couple more years of reliable service before that happens.