My 1987 E-150 Van with a 5.8L 4bbl will not start when it is hot. During the summer it would run fine, but it had to cool off for at least an hour before it would start. Cranks fine - and no, I don’t think it is fuel, because I don’t even get a hint that it will start.
Lately, it stalls after 10 to 15 minutes of running and will not start for 4 hours (the longest I’ve had the patience to try) - but in the morning, it starts right up and runs like nothing is wrong - for 10 minutes.
I’ve changed the ignition module (the one on the fender), and the distributor. Coil is next.
I am sure this must be a heat related electrical problem, but what?
Coil is next.
Congratulations. You just might have finally “nailed it”. Let us know how you make out.
For the record, if I were guessing that would have been at the top of the list. To do diagnosis I would have first checked the spark and then the voltage pulses at the coil primary. But if that were within your level of skills and equipment I’m guessing you wouldn’t have asked.
It’s not at all uncommon for old coils to become heat sensitive. And when you shut a warm engine down, the temperature under the hood rises. With the cooling fan and the water pump shut off, the heat internal to the engine radiates out the surfaces and raises the underhood temperature. Things subject to heat sensitivity can show up then. That’s why your engine won’t start again until the engine cools down.
The coil very well may be causing the issue but before you go and purchase a new one I suggest you first verify that power is getting to it while the trouble is occurring, just in case the problem is really with the power supply.
While this sounds outrageous there was a radio noise suppressor condensor attached at the coil on many Fords of that period which can get hot and short out internally. Disconnecting the condensor will not effect the engine and so it can be tested for free.
Seems like you are on the right track… When the vehicle shut down initially …that was when the tests should have begun… When it doesn’t start…look for spark…its one of the very first things on the list. You will probably be OK after a new coil. Good luck