[brianswyatt]

Just finished a complete restoration on a 66 with a 289. Rebuild the engine myself and topped it off with a holley 650. It is being fed with a holley high flow mechanical fuel pump and I replaced the fuel sending unit when I cleaned out the tank (sludge in it prior to restoration). New stainless fuel line and new fuel filter. MSD box and MSD distributor and new MSD plug wires. Idles like a champ and runs scary fast for a bit (3-4 miles). At cruising speed, it will start to die out by sputtering like it is running out of gas. It dies out fully and after sitting for a bit will start up and run like a champ again. After getting back on the road, it will die out just as before after not getting quite as far as before. Sputter, sputter, and die. Any help is welcomed.

[rbinck]

Vapor lock? If you have headers maybe close to fuel line.

[brianswyatt]

No headers - hypo exhaust manifold. Checked fuel line all the way to the tank.

[Veronica]

Hello. When the car re-starts, does it fire right up, or do you have to crank on it for little while?

[brianswyatt]

Seems to fire right up.

[Veronica]

Hi again. I think that I would start with the easy stuff, then. Check the fuel filter first. If you cleaned out an old gas tank, it's very difficult to get every little bit of crud out of there. The filter could have caught the last little bits of something. I doubt if it's an electrical problem. If it was that, normally, that's something that either won't start at all, or, once it dies, it's dead until the problem is corrected, unless it's a marginal coil. It sounds like everything in front of the tank is brand new, so, the old gas tank would be the first cause that I checked.

[dlm906]

I had a similar problem on our '73 Cougar it would idle forever but once I got a mile down the road it would die. It turned out the vent tube on the top of the tank was was plugged from corrosion so it was creating a vacuum. I know the later model tanks are different from the older ones so does it have a vented gas cap? You could try running it without the cap and see what happens.

[brianswyatt]

thanks for that heads up. Looking everything over again. I will post when I discover the gremlin.