Stumped, need help!

[low'n slow]

Last week I was driving the 68 when it died like it had run out of gas although the tank read 1/4 full. I thought the gauge had gone out, so I got a gas can and put in a few gallons with no difference. It idles ok, but cuts out and dies.

Pulled the sender and pickup to check for a clog, found none. Blew out all the lines, put in an inline filter and a new fuel pump. No change. It idles fine, runs OK until about 30 mph and it will cut in and out and die.

Rebuilt the carb and put in a HEI distributor I had for it. Still have the same problem.

Any ideas?

Thanks

[67dragtruck]

Wow. It sounds like you had it covered. That's rough. I'll give it some more thought.

[Classic Heartbeat]

Could be electrical. You might check the wires bolted to the little stud on the right fender. The 30 mile per hour thing could be coincidental. WES

[low'n slow]

I was thinking of tracing out the wiring under the dash, on the fender, etc. I will let you know..
Thanks

[uno67]

i had they same problem. i had never replaced the fuel hose from the tank to the steel lines. they were old an cracked and ballooned. so it would idle fine but when i would get to driving it with the more demand for fuel it would suck air in and shut off. wait a little bit it would start back up and run fine after the air bleed out of the line and filled back up with fuel. so i would check the hoses see if thats the problem.

[low'n slow]

The wires bolted to the stud are tight, I've run the motor and wiggled all the wires to no avail. The thing that puzzles me is the sudden onset of the problem.

It is a 6 cylinder with a floor mounted 3 speed.

[skchevota]

Sounds like fuel, Check the gas cap vent.
Also, I would install a test guage to make sure you have fuel pressure when it stalls. If it does, i would open up the carb and see if it is gummed up.
Also check for possibe water in fuel.
Did you run a wire from the fuse box to your HEI.
The original ignition wire for the points is a resistor wire and wont supply the HEI with 12 volts.

[VetteVet]

The gas tank may not be venting well. Pull the cap and check to see if it will go over thirty.

[skchevota]

Opps, I just re read your post and see that you already rebuilt the carb. But I would still check the fuel pressure and take a sample of fuel in a jare to check for water. If all that is good, Hook a volt meter up to your hei power lead at the distributor and then take it for a drive, if you have power when it stalls, you will know it is not in your wiring.
You might want to check your engine to frame/body grounds as well.

[low'n slow]

I connected the distributor directly to the battery and it still stalls and stutters. That eliminates a wiring problem. When it stalled, I popped the hood and glanced at the fuel filter, it had fuel in it. I've checked and rechecked the fuel lines, thay are clear and the rubber ones are in good shape. So, I'm back to the carb. I'll pull it apart again and blow out all the little holes and stuff.

[jholley]

Two thoughts on your problem. Either the fuel tank is not vented and it's creating a vacuum lock or maybe your exhaust is too close to the fuel line and you are getting a vapor lock.

[texastrendz]

sounds like it is pulling a vacuum for sure, check take vent. after it stalls pull your gas cap and see if has pulled a vacuum. you will here a sucking noise as soon as you pull it. just a thought

[skchevota]

Speaking of exhaust, any chance something is blocking ot up? crushed pipe,muffler gon bad, disgruntled neighbor with a potato???

[low'n slow]

I will try the gas cap, but why would it all of the sudden do that? I have been driving the truck for 6 months. Do gas caps go bad?

[72BLUZ]

any thing vented can become clogged at any giving time. the next thing i would check would be the plugs and wires. they can cause this problem as well as the other items that have aready been posted. check your battery votage as well as your alternator. low voltage can cause poor acceleration.