1971 Chevy C10 Shutting off

[Darreola562]

I have a 1971 c10 350 that I let idle for about 30 minutes and once i do that it will shut off. Not sure what going on with it as it starts up just fine I let it sit for30 minutes and it will automatically shut off like clock work. Does anyone have an idea as to why this happens?

[B. W.]

Need more info.

Does it have HEI distributor or points?

Does it have an electric fuel pump?

When it shuts off check for spark. If it has spark then check for fuel ( air cleaner off, work the throttle, you should see fuel squirting into the carb)

[Darreola562]

Originally Posted by B. W.

Need more info.

Does it have HEI distributor or points?

Does it have an electric fuel pump?

When it shuts off check for spark. If it has spark then check for fuel ( air cleaner off, work the throttle, you should see fuel squirting into the carb)

It has an electric fuel pump and has a distributor. When it shuts off I attempt to turn it back on by pumping the pedal and it turns on but will shut off within 5 seconds. If I let about 20 minutes past it will turn on once more for another 30 minutes or so.

[dagnabbitt]

Ignition coil?

[Darreola562]

Originally Posted by dagnabbitt

Ignition coil?

Would the ignition coil give this symptom?

[geezer#99]

It’s your pump.
It heats up and quits.
What carb do you have?

[dagnabbitt]

Originally Posted by Darreola562

Would the ignition coil give this symptom?

If it shuts off without sputtering - like you just turned the key - and you can restart it a few minutes later like nothing happened, it might be.

[demian5]

Originally Posted by geezer#99

It’s your pump.
It heats up and quits.
What carb do you have?

Or there isn't a sufficient vent in the tank and the pump just cant suck any more fuel out.

[Darreola562]

Originally Posted by geezer#99

It’s your pump.
It heats up and quits.
What carb do you have?

I have a Holley carb.

Hearing different things some people say ignition coil other say pump.

Wouldn’t the pump just stop working all together rather then just heat up and shut off?

[Darreola562]

Originally Posted by dagnabbitt

If it shuts off without sputtering - like you just turned the key - and you can restart it a few minutes later like nothing happened, it might be.

Yes, it sounds as if it runs out of fuel and just sputters and turns off. If I immediately attempt to turn on it will while I’m giving it gas but will then last maybe 5 seconds and once again turn off.

[Darreola562]

Originally Posted by demian5

Or there isn't a sufficient vent in the tank and the pump just cant suck any more fuel out.

Wouldn’t this be the case as soon as I turn it on? It takes approximately 30 minutes before it shuts off.

How would I fix the vent issue?

[HO455]

What happens when you drive it? It could be a bad coil that heats up and quits working then quickly cools and resumes working. You need to test to see if you have spark as soon as it quits. Then you can start trouble shooting the system that has failed. (i.e. fuel or spark) When trouble shooting you always want to check in the middle to reduce the problem area. For example test for spark at the coil wire (non HEI) then you know the problem lies in the coil and its power wires if you find no spark. If you have spark then the problem would lie in the cap or the timing. Take time to write down the symptoms and think about how the systems are supposed to work.
Good luck.
And I have to ask why are you idling for 30 minutes?

[demian5]

Originally Posted by Darreola562

Wouldn’t this be the case as soon as I turn it on? It takes approximately 30 minutes before it shuts off.

How would I fix the vent issue?

No, try it one of to ways:
1. When it dies, take gas cap off see if there is a rush of air and you can start it up.
2. Leave cap loose or off and run it and see if it still dies.

Also, l when it dies, if you take air cleaner off and pump the throttle, does it squirt gas into the carb? If not, then gas may not be your issue.

Gotta figure out if it ir running out of gas or losing spark.


I second the "what does it do when you drive it?" I dont normally let my truck sit and idle for more than a few minutes.

[garyd1961]

What demain5 says. You need to find out if it's losing gas or spark.