Holley 600 dumping fuel

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May 30, 2015 | 11:11 AM

jarrettseiple

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From: Eggleston, Va

Holley 600 dumping fuel

i've got a '77 f150 with a 351m and a holley 600 that is dumping so much fuel that it was running out of exhaust manifold, for whatever its worth, it only dumps out of driverside manifold (on level shop floor). I just rebuilt the carb, including replacing the powervalve, and then changed spark plugs, and oil, and it ran so dang good for a bit I thought it was timing, so I timed it, then replaced original distributor, and went to time it again, and am back to where I started...exhaust burns the eyeballs.

May 30, 2015 | 10:00 PM

Jrgunn5150

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So it ran well after your rebuild, then you tried to time it, and now it's dumping fuel again, is that correct?

May 30, 2015 | 10:06 PM

slpcth

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From: Foresthill, CA

I would pull the carb again and go back thru it. Sounds like a jet might have backed out or the powervalve got damaged from a backfire. Repairs do go wrong sometimes I have found that double checking what was done previously could save a lot of time and trouble.

May 30, 2015 | 10:24 PM

jarrettseiple

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From: Eggleston, Va

It ran better after the rebuild, but exhaust still had fuel, just not as much. I think main reason it ran better was clearing engine of all gas/oil mix and changing of fouled plugs. I'm going to tear carb down again and go through it with a fine tooth comb.
Carb ran great years ago, then engine went south and it sat. Had another engine rebuilt and put in and carb was acting so bad that we had to throw timing way off to compensate.

May 31, 2015 | 01:49 AM

Jrgunn5150

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Ok, yeah, I'd double check the carb then for sure. Let us know what you find!

May 31, 2015 | 07:21 AM

dentsides

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From: NM

Double check the power valve, accelerator pump and diaphram.

Jun 14, 2015 | 07:24 PM

jarrettseiple

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From: Eggleston, Va

While waiting for new diaphragm to come in mail, my buddy gave me an edelbrock and rebuild kit. Wow. Simplicity compared to Holley. Once again, I drained the oil, replaced plugs, and now I believe I have stopped the fuel draining into the engine. Runs nice and clean with no smoke. But now if I leave the truck sit for more than a few hours, the edelbrock acts as if it lost its prime. I have a clear fuel filter filled with fuel, but she just won't start unless I drip a bit of fuel in the carb. I replaced the springs on the metering needles, but haven't replaced the needles themselves. I tried loosening the "kidney" plates and jiggled the needles a bit to see if they were hung up, but still no better results. Once I get the truck fired up, she'll start right up for the next couple hours.