DUH

Long question, but bear with me... Husband has 86 Bronco w/rebuilt 302. Few months back, started just shuttin off while driving, even at 50 mph. Later, he'd go to store, bronco fine, turn engine off, come back out and it'd be dead... Dropped off at mechanic, the next mornin they'd start it and run it for a couple of hours at a time, drive it around, nothing wrong. This scenario happed a couple of times. They checked all wiring connections, couldn't find problem, so they replace ignit. contrl. mod. Ran okay for a few days then started crappin out again. I insisted was a fuel pump problem. Replaced fuel injectors and pumps, still no help. Heard through grapevine, that ignit contrl mods are notorious for bein unreliable once they get hot. Took to napa and they said it tested fine, but do not know if they tested again after it was nice and hot. Plannin on replacing stock cntrl mod with hei system but don't want to spend the 200 bucks if could be somethin else. Anyone else have a similar problem? HELP???

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Long question, but bear with me... Husband has 86 Bronco w/rebuilt 302. Few months back, started just shuttin off while driving, even at 50 mph. Later, he'd go to store, bronco fine, turn engine off, come back out and it'd be dead... Dropped off at mechanic, the next mornin they'd start it and run it for a couple of hours at a time, drive it around, nothing wrong. This scenario happed a couple of times. They checked all wiring connections, couldn't find problem, so they replace ignit. contrl. mod. Ran okay for a few days then started crappin out again. I insisted was a fuel pump problem. Replaced fuel injectors and pumps, still no help. Heard through grapevine, that ignit contrl mods are notorious for bein unreliable once they get hot. Took to napa and they said it tested fine, but do not know if they tested again after it was nice and hot. Plannin on replacing stock cntrl mod with hei system but don't want to spend the 200 bucks if could be somethin else. Anyone else have a similar problem? HELP???

The times the Bronco wouldn't start, did it crank at all or was the battery completely dead?

Oh, it cranked, just didn't turn over, most of the time. Thanks.

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Oh, it cranked, just didn't turn over, most of the time. Thanks.

Well it definitely sounds like an electronics problem you're experiencing. Typically, these things are better tested once it is up to operating temperature. Instead of going with an aftermarket system I would consider replacing the factory system first just to save a few $. You are on the right path for troubleshooting though. Unfortunately I'mjust not familiar enough with the older electronics systems from 1986 so I'm not sure what sensors exist and what sensors don't. I had the exact same problem in my Excursion this weekend and it ended up being a bad cam position sensor, but I don't know whether or not your 302 has something similar to it. Mine didn't trip the "service engine soon" light so it was a little harder for the dealership to find until I told them about it (other people online experienced similar problems).

Good luck with the ignition setup, perhaps someone else will be able to chime in with a better suggestion.

yo,
TFI's are notorious or opening up under heat.
Read this:
http://www.summitlake.com/COMMENTARY/Ford_Ignitions.html

have it tested using info shown in a link in my web page under Technical; "Ignition"

Better yet, have hubby move it to a better area such as shown in a Mustang article in same Ignition section.

Thanks to ya both for the replies. We knew about the problem with tfi units. We've replaced it twice w/in the last few years (both times the units tested bad), so we've decided to move onto aftermarket. Prayin it works or it'll move on to target practice. Thank ye!!!