Bronco won't run

[csangster]

About a month ago, I was firing up my newly rebuilt bronco (by me) and getting ready to go for a spin. It had been running fine since November 2020. I was putting miles on it to break it in for the first oil change and just driving around enjoying it. I had driven it ~ 500 miles total with no issues. It needed a tune up but was running fine at my home elevation of 7500ft and down in town at 5000 ft

It fired up fine, idled for a while........then died. Then I couldn't start it.

Nothing changed, nadda....I hadn't changed a thing from when I parked it a week earlier.

Now it will fire up.......run for around 15-30 seconds then die and it won't restart.

Engine is a mild 351W build...

With the suddenness of the failure, it only makes sense that it is an electrical/ignition issue. It has a points/condenser/stock distributor, flamethrower coil.

I replaced the ballast resistor and voltage regulator because I though they might have failed suddenly.

I've played with the timing and screwed it up even more.

I pulled the plugs to see if I was fouling plugs.......nothing, clean as a button.

When it does run for those brief 30 seconds......it runs great......no knocks, no ticks, good oil pressure.

I am flabbergasted and just plain frustrated.

Please help.

Thanks,
Chris

 

[75MIKE]

Do you have a spare coil you could try?

 

[SHX669]

Do you have the factory/stock wiring or have you replaced some or all of it? If you have the factory wiring you don't need the ballast resistor as there is already a resistor wire in the " run circuit". Dont know if this is contributing to your issue but certainly wouldn't help.

 

[B RON CO]

Hi, I'm not sure if the Pertronix Flamethrower coil is the right coil to use with points and condenser ignition, but I not am knowledgeable with coil Ohms ratings. I would probably get a stock coil.
I would use a test light and check for current at the positive side of the coil before and after it stalls. If you lose current to the coil you have no spark.
If you have a tach in the Bronco unhook it. A defective tach can kill your spark.
I would get the best Echlin brand points and condenser from Napa or Motorcraft brand if you can find it. I think the chances are good it is the condenser.
Good luck

 

[Rustytruck]

try putting your old points condenser back in.

 

[Jfryjfry]

Sounds like fuel to me. Try starting fluid when it dies and see if it relights. If so, then it’s fuel.
I don’t see what you have for a fuel system. Carb, Ford efi, fitech, etc