67 coupe stalling

[Burgers]

Ok, I've been working on this problem for about 1 month on and off and here's the story.
Recently got the car up and running and was bringing it to my house from the hobby shop where I work on it. After driving about 1 hour (it was running like a champ) it started running rough. I put it in neutral and the engine cut out. After pulling over it would not start for about 10 min and would run for about 10 more and then the same thing would occur.
Finally got it home and replaced just about everything I hadn't to that point. (fuel pump, cleaned the fuel filter, new coil, rechecked the idle mixture and float level on the carb and triple checked the timing) Nothing seemed to fix this problem. Now the car will idle and warm up fine in the driveway (it starts fine after warmed up) but after about 5 min of actual driving the engine will feel like it's missing and then cut out. I'll wait ten min and it will run again.
Here's the engine's particulars - stock 289 motor with a holley intake and 4 brl carb, stock mech fuel pump. It has aftermarket dual exhuast and a four speed manual transmission. Any help or ideas would be great as I'm just about out of them.

thanks

 

[Ozsum2]

Kind of hard to figure, but it sounds like something is getting hot and shorting out the electrical system. Coil?

 

[Burgers]

don't know, I replaced the coil. Is there a particular place that would be better to mount it? I've got it on top of intake manifold next to the carb right now. I've seen it mounted between the water pump and the alternator before ...

 

[2nd Mustang]

So many possibilities. Vacuum leak? Bad plug and/or plug wires? Do you have points in the distributor, maybe out of adjustment? Loose eletrical connection?

 

[hdgapeach]

If no points, electronic pick up in the dizzy might be on it's way out....
Might also try the "wiggle" test while it's idling in the driveway (get it running and pop the hood up and wiggle all the wires to try to replicate the condition). You just might find a wire that is broken inside the insulation.....
Cap, rotor button and coil wire condition?

 

[JB66]

My vote is for the pickup filter in the gas tank clogging. How long was the car sitting and not running? Did you (or anyone else) put any cleaners or additives in the tank before your drive home or when it was sitting? "T" in a fuel pump pressure guage and see what happens when you're driving for a while.

 

[pabear89]

Check the rubber fuel lines, the on at the tank and under the drivers door area.
It sounds like your sucking air thru cracked lines.
I have had that happen even without leaks.

PB

 

[notny41]

I'm going to be watching this thread because it sounds like the exact same problem I am/was having. I don't know if I solved my problem yet because I haven't had enough time to drive it, but I found out that the plug wire from my coil to my distributor was all fat and mushy compared to the rest of my wires. I made a new one from some extra wire I had and I haven't had my car stall on me since.

The one I took out that was fat and mushy was also a little oily on the end going into the coil. I am told that those coils are oil-filled so I'm wondering if mine was leaking due to high temps maybe. But I figure the fact that it was expanding and the oily residue on it might have been working itself out of the top of the coil and losing the electrical contact.

Also, when I measured the resistance, the mushy one was about double the resistance as the new one I made.

I also have a stock 289 with dual and 4bbl and a 4 speed. Wierd!

The first few times I though I had run out of gas. But it would start again after a little while...

 

[69Horse]

I had a similar problem with a 69 Pickup. Check all your rubber fuel line. If any of it is soft or spongy, replace it. On my truck it would collapse the fuel line when running. Also add a second inline fuel filter, one that's clear. Once the engine quits, jump out and take a look at it, if it's empty you've got a fuel delivery problem, i.e. pickup clogging in the tank, fuel line blockage, or bad pump. Pretty cheap way of narrowing it down.