carburator problems

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Nov 30, 2012 | 10:46 AM

ccoreyman

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carburator problems

I have a 1977 ford 250 custom, with a 351 modified, when I checked the timing and shut the engine off I noticed gas leaking out of the vacuum port to distributor. This is a newly rebuilt carb I purchased from a reputable company (motorcraft carb). It refuses to idle properly when warm and runs great when driving down the road. Any ideas? Could it be an ignition problem, i.e. uplift coil, coil, or ignition module? Should gas even be able to leak out of there?

Nov 30, 2012 | 10:55 AM

NumberDummy

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From: Simi Valley, CA

It's a newly rebuilt carb? You bought a rebuilt carb, lawd only knows when it was rebuilt.

Rebuilt carbs may sit on shelves for years before they are sold. Climate conditions can cause accelerator pumps, check valves to harden up, gaskets to shrink, so when installed, the carbs leak like sieves.

Nov 30, 2012 | 11:08 AM

ccoreyman

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Thanks

I never thought of that, I guess I'll rebuild the old carb and see what happens! I guess I should of added that it ran great for one day idled, started perfectly. It started running like crap, so I tried to fine tune the air, gas mixture, thats when it started leaking (open about one and a quarter turns)

Nov 30, 2012 | 01:05 PM

fmc400

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From: Austin, TX

Is this a ported vacuum port? Ported vacuum is above the throttle plates. The only explanation I can think of for that is a cracked throttle body. Something has to go seriously wrong for fuel to come out of where you are describing.

Nov 30, 2012 | 02:09 PM

ccoreyman

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carburator

It is the vacuum advance hose from bottom of carb to distributor that leaks fuel when turned off after idling for a bit.

Nov 30, 2012 | 02:21 PM

fmc400

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From: Austin, TX

If fuel isn't leaking out anywhere else, and there's no indication that you're dumping fuel because of a stuck float (such as fuel coming out of the bowl vents), then the only explanation for what you're seeing is a cracked throttle body. I'd try to return it to the store if you can.

Dec 1, 2012 | 08:42 AM

ccoreyman

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carburator

Ok, i'm gonna rebuild old one and try to get my money back on one I bought. Should have listened to my nephew and bought a new Holly!!! Lesson learned!!!

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Dec 3, 2012 | 10:25 AM

ccoreyman

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carburator problems

Yes, 2 fuel filters one from tank and one at carb, That still would'nt explain gas leaking from vaccum advance line. They are sending me a replacement carb at no charge, they said there is no way gas should be leaking from there unless there is a crack in the body. Thank you to everybody for your input! This is a great site and I'm glad I lucked out on my google seach when this site popped up!!!!