Here's the issues, an intermittent issue. Sometimes the truck will not start, hot or cold. Turns over fine, has 5.5 lbs fuel pressure. You might try to start it 8 times and nothing then boom fires right up. Sometimes it will die while driving, not a stumble like fuel. It just shuts off. Usually it will restart.
It's so intermittent I cant detect if it's spark, I checked it on one occasion it had no spark at the plug. Replaced the plug, tried it again and it started right up.
I suspected the coil and replaced it. Ran good for one day, it has new regulator, new battery.
I stumped guys and don't know what I'm overlooking.

It does however have a "Chinese" knock off electronic distributor from the previous owner.

 

Possibly the ignition switch

 

Could be, however I replaced that a couple months ago. Any idea how to test it?

 

^^x2
That started happening to me, i changed the ignition switch and no more issues.

 

Had a similar issue with a Crane 700 ignition, turned out to be a heat related intermittent open circuit in the control box. Drove me out of my mind. In my case, when hot suddenly a 6 cylinder turned into a 4 cylinder, or no cylinder. Replaced it with a Pertronix and never had the problem again. Check that distributor?

 

Is this for the '73 in your profile?
My first suspicion would be the "Chinese" ignition.
What type of ignition are you dealing with? Any name or information on it?
A '73 originally had points and condenser.

 

You've indicated that at some point during the failure condition, there was no spark. It's hard to tell you where to troubleshoot further without knowing what kind of ignition system you're working with. However, it's likely isolated there.

 

A lot of times it's not so much the ignition switch itself, but the wiring and connector behind it. Previous owners love to tap into those key on hot wires with those horrible 3 way splices causing an intermittent short in your ignition.

 

Gotta "love" Scotch-locks.

 

I had a brand new cheap Chinese pickup/stator in the distributor do that to me, I finally changed it out on a guess as it was hard to diagnose, it would start most of the time but every now and then it fail to start.

 

I've also had a couple Duraspark boxes do this to me. Most of the time it was a hot failure, after I was already driving the truck. Occasionally though, they would fail I guess just from age.

 

You guys realize that "HoustonDave" bumped a three month old thread right?

Zues1 hasn't been around since then...guess we won't know if he fixed it or not.

 

Necro-posting! Gets us every time!

 

Yup. I've "answered" some that were 10 years old .

 

Hey, I stole the term from you