Weird Problem - Is it fuel or electric?

[64SprintV8]

OK so here is the situation: 289HiPo w/Pertronix II Ignition also has alternator instead of generator, no voltage regulator that I have seen.

The problem reared it's head 2 weeks ago. I was out driving and having a nice time for about an hour or so. On my way home the car just dies. I do some looking/testing of various things and I think maybe it is the mechanical fuel pump since the new clear filter is not showing full. Put a cup of gas directly in the carb and try to start, no joy. Weird unless spark related, right?

Get towed home, unload it from truck and the car starts right up and I drive it in the garage! So then I think maybe it was something in the fuel tank that restricted the flow and got jostled loose on the 5 minute ride to my house. Still wary I ran the car this weekend and while warming it up for 15 minutes are so, it died twice while idling, But started right up after each. I foolishly took it for a drive and made it about a 1/4 mile and it died for good. Being stubborn, I pushed it home and up a little hill with some friends. I decide to try the FlameThrower II off my Sprint to see of it had gone bad. No difference, no start. Tried it about an 2 hours later and it fired right up with the original coil.

So today, I decided to do more testing, I let it idle in my drive way and at about the 25 minute mark it died, started once after that but died again, then nada. Car is at normal temp, clear plastic fuel filter is full to and clear.

About 1 1/2 -2 hours later it fires right up like nothing is wrong.

BTW, I did have a bad Flame Thrower coil last year (June) which I replaced with the Flame Thrower II and a new set of Pertronix wires, Cap, Rotor, and a new module.

The only other thing changed out was the fuel filter. From a solid metal to a clear plastic one.

So, what's the problem?

1) Pertronix II module?

2) Vapor Lock? BTW the carb does not even get that hot to the touch, so I doubt the front bowl is boiling and there are no metal fuel lines on the engine to the carb

3) Fuel pump? Overheating, vacuum, leaky diaphragm, low psi, etc?

4) Ignition switch? Checked for heat and it is not to the touch at or around the key.

Right now I am just frustrated and gun shy to take the car anywhere until I find this gremlin.

I was going to go ahead an purchase another Pertronix II and see it that nixes the problem, then on the the fuel pump, then the carburetor.

Thanks in advance for your counsel.

[ew1usnr]

An intermittent electrical problem means that it is probably a loose connection. My guess is a loose connection between the primary wire from the coil to the top of the distributor cap. You said that you had changed the coil. Check the connection where the wire plugs into the top of the distributor cap. Maybe the wire did not get plugged in all the way and it has vibrated loose.

[Jeff W]

I would:
1) warm up to get into the "no start" situation.
2) pull a plug wire off of the spark plug side and insert a spare spark plug on the end of the wire.
3) ground the metal base of this loose spark plug against a bare piece of metal such as an unpainted valve cover bolt or bracket.
4) have a helper crank the engine (trying to start it) while you are watching for the nice strong spark from that plug.

There are other ways to check for spark but this is a nice safe process that keeps your hand out of the fan.

Should help narrow your problem and show you which fork (gas or ignition) you need to go down.

[Nathan289]

Pertronix module over heating?
Kinda like an electronic vapor lock?

Check for spark after it dies would be the first place to look..
If no spark, check to see if you are getting power to the coil from the ignition switch..

[64SprintV8]

Update: I spoke with Pertronix today and the said it sounds like a low voltage issue since the module needs at least 8v to operate correctly. Also, I found out that the factory wiring has a ballastor resitance wire from the ignition switch. Maybe the P1 could handle the lower voltage via resistance wire without incident but the P2 can't and to Nathan's point it basically causes and electronic vapor lock (shutdown) due to overheating and drawing of more voltage, etc. Then once it is cooled down it starts back up like normal, until it gets hot again.

The easy fix supposedly is to disconnect the postive power wire from the module to the coil and wire it to a 12v switched source via the fuse block, like the radio.

I guess I will try that and move forward.

Thoughts?

[Nathan289]

Center post back of ignition Switch is a keyed source.
Might want to consider an inline fuse.. check with pertronix on what amp.. I'm guessing 15 amp should be ok..