Just wondering if anyone can help me diagnose my truck. It is a 1986 Bronco 2 with the 2.9l fuel injected, at temps above 70 degrees it will run fine for about 20 to 30 minutes and then dies, it will not restart for about another 30 to 40 minutes, then it will run again for another 20-30 min unless the temp has dropped to under 70. I have replaced both fuel pumps, the fuel psi regulator, the TPS and map sensors and found a corroded wire on fuel pump relay and repaired wire and replaced relay. I.m getting ready to replace the coil due to it not testing properly. Any suggestions would be helpful and appreciated.
The coil was going to be the first thing to test. Heat-sensitive driveability problems usually lead to a bad coil diagnosis. Also the ignition module is suspect. On older Ford’s with electronic ignition, these have always been a problem. Especially the modules installed in the distributors.
It’s probably a failing ignition module. (Little gray box on the side of the distributor.)
This vehicle is a TFI-IV model and the modules are prone to heat failures. Testing the module will be a waste of time because it may test fine and still be bad.
Summer heat is usually when they start dropping dead and coming back to life; at least most of the time on the coming back to life part.
If you change this module be SURE to use the special electrolytic grease that comes with the mew module or it too will soon fail.
For more on these modules do a net search for “TFI Settlement”.
I hate (love) to say this about an 86 Bronco II. Get rid of it before it… It sounds a little mean to say it but it could be good advice.