67 c10 dies when idling

[Guy Dudebro]

I have a '67 c10 half ton. New problem: unless I give the engine some gas the engine dies. It will die when at a stoplight. And when I start the ignition, it will only start and keep running if I'm giving the pedal some gas. Release the pedal and it dies.

The fuel pump is new. And I just replaced the fuel filter thinking it may be that. My fuel filter is under the cab and there is NOT on between the pump and carb.

Any input on what the issue might be?

[geezer#99]

What motor?
What carb?
Have you tried turning the idle up?
Possible vacuum leak too!

[1972BlueC20]

I would never put a fuel filter between the tank and the fuel pump. I don't think it's designed to go though a filter before the fuel pump. Change the location of the fuel filter from underneath the cab to between the pump and carb and I think that might fix your problem. Also check and replace if necessary the little paper filter in the carb if you have a stock quadrajet carb (It's behind where the fuel line screws into the carb). It may be clogged or collapsed. Also check your idle speed.

[Guy Dudebro]

Its a 327 motor. Not sure what type of carb it is. Brand is Edelbrock.
The filter between the tank and fuel pump was already there. Was that how it came out of the factory? And how do I check my idle speed? Thanks!

[In The Ten Ring]

I had this same exact problem with my 1972 after it sat for 10 years. It would start and run and drive but quit at a red light.

I pulled my gas tank and found it to be coated in flash rust. It was pretty awful. I had the tank "renewed" at a local radiator shop and I had the carb rebuilt by a mechanic. The mechanic said (and this is a real quote) "I wish I had taken a picture of that carb because I have never seen so much fine rust fall out of a bowl in my entire life."

He also suggested I replace every inch of my fuel lines or (another real quote) "you'll be back in here to see me after about two weeks of driving for another carb rebuild."

I was planning on putting an extra filter under the cab but now I think I'll dispense with that. I'll stick with the filter in the carb.

[geezer#99]

Edelbrock carb and you just changed the fuel pump.
Now you have too much fuel pressure and you're flooding a bit.
The cure is to install a fuel regulator. Eddy carbs don't like more than 5 psi.
Idle screw is on drivers side facing the front. Not the two mixture screws, the one on the linkage.

[1972BlueC20]

These trucks came with a filter only inside the carb. It was the little paper filter element inside the carb inlet. Since you have an edelbrock carb now you don't have a filter in the carb anymore. Everyone usually added an inline filter between the carb and pump. I would def check the gas tank for rust ect, and also eliminate the fuel filter that is under the cab. Add a new filter between the carb and pump.

As for the Edelbrock getting too much fuel, it's probably true. Edelbrock recommends about 5.5 - 6 psi max. I think the stock pump puts out well over 7 PSI or more, however I'm running a stock fuel pump and an Edelbrock carb and I'm not having any idle issues. I do have trouble sometimes with hot starts but that's it.

I have a fuel pressure regulator but just haven't put in on yet, it's on my to-do list.

I would try relocating the fuel filter first because it's easy, cheap and needs to be done anyways. Then I would move on to your next suspicion after you've done that and eliminated that as a cause.

[Guy Dudebro]

Thanks everyone! I think I also have a vacuum link. There's a loud whine that sounds like its coming from near the carb. I'll replace that hose and probably the fuel line. It looks pretty old. Hope I don't have to replace the gas tank though as it would be pretty pricey to get one.

Where do I put the fuel regulator? Is that between the pump and carb?

[1972BlueC20]

yes it would go between the carb and the pump before the filter

so, pump > regulator > filter > carb

Gas tanks are about $150-$180, sending units are about $30-$50

[Guy Dudebro]

Great. Thanks for the help. Busy weekend ahead.

[geezer#99]

Easy way to check if you need a regulator is look inside the carb while it's idling. You see any raw fuel then might need a reg. Fix the vac leak first.