Hey all, I figured I'd post this in case it could help anybody.
A few weeks ago my Bronco would not start when it was hot. It would always fire up when cold, but I'd drive it any considerable distance and it would not start again until it had cooled down.

Due to the fact that it has been in the mid 90's, and the fact that the gas stations have all gone to summer fuel (i.e. high ethanol content = lowered boiling point), I assumed it was vapor lock. I tried a bunch of vapor lock remedies to no avail. Eventually I ended up hooking up my timing light to no.1 plug wire and got no flash. I tried the high tension lead from the coil, still no strobe. I'm not getting spark.

A friend of mine overheard me venting my problems and said did you try the magnetic pickup? Apparently the same thing happened to him years ago and the tow truck driver said he'd seen it a million times. I never thought to look there, but I replaced it and sure enough, problem solved!

This is the part I'm talking about for anyone who isn't sure. I guess when they start to go bad they give vapor lock type symptoms.



Image borrowed from this website:
Ask a Mechanic - Ignition System Basics