I cant figure this out, another opinion would be helpful.

I have a Holley 600 cfm carb w/ electric choke and vacume secondaries. Electric fuel pump providing 6-7 psi. The motor runs fine for about 10 minutes or so and then acts like its not getting enough fuel, then it clears up and runs good again for a while and repeats this over and over........

I changed the fuel filter and supply line from the tank to the carb, cleaned and rebuilt the carb, set the float levels, adjusted idle mixture, set the timing to 12*, vacume is at about 14...

What could be the issue?
(Perhaps I missed something when I did the rebuild, couldI it be ignition related, vacume advance/dizzy adjustment)
Im going trying to get it running correctly and reliably. Any advice would be appreciated, thanks.

I'm sure someone will be along that is much more knowledgeable about these things but a couple of clarifying items things may help identify the culprit.
Is this a new issue or is this something has been ongoing for a while. You mention a carb rebuild. Did it do this prior to the rebuild or after. When did the symptoms start ?

Do you have a fuel pressure gauge inline? What is that showing when the issue crops up.
Does it perform ok when driving ? or is it only at idle?
What type of fuel pickup do you have. (could there be an intermittent partial blockage)
Can you easily swap out the fuel pump to remove that from the equation?

Someone can talk to the carb settings, I'm not one of them.

Brett

This all started a few years ago and its been mostly parked since. I have changed carbs and fuel pumps two or three times. One used one to another used one, rebuilding them before installing. I had an Edelbrock 1406 that ran good on the street and bad on the trail befoe going to the modified Holleys (vent baffle, vent tube & spring loaded float valves). I do have pressure gauge in line but its under the hood so it makes it hard to see while driving. I'm confident the pump/s are not bad. I have also checked the pick up screen in the tank and it was fine, no blockage.

I had similar issues after replacing my tank, fuel lines, and pump. Finally traced it to the fitting in the picture. That fitting had a filter in it that I didn't realize. It was clogged from very fine material that probably came from the new fuel lines. Once I removed that filter- never had another issue.

Do you by chance have something similar?

I have an Edelbrock carb that I can rebuild and stick on there to see if that changes things. My fingers are crossed!!

Are you running a two barrel or four barrel? I have a rebuilt 2150 Motorcraft two barrel if you want to try it. It would only take a few minutes to swap.

Im currently running 4 barrel, I will try the edelbrock first. If that doesn't work out I will take you up on that, I have a 2 barrel intake I could swap.

When you rebuild the edelbrock pull the fuel fitting out and get the filter behind it.

Check you're float/s. Sounds like the primary float may be sticking. That would account for why it does it on and off. It sure sounds like a fuel supply problem.

Zoso- thanks for the tip, I will make sure to change that filter.

Crazyone- I have checked and double checked all of that. I seems to be fuel delivery to me too, just can't seem to slay that "Gremlin". I just dont see clearly through the frustration.

Jts, are you going to be around on Tuesday? I'll be in your area and could stop by to look it over.

Has anybody mentioned vapor lock? even with an electric pump its not uncommon.
do you have a non-metal type spacer under the carb? maybe a heat shield and shield your fuel line as well.