Carb? problems

phat46 · September 06, 2009, 04:50:26 PM

I have an Edelbrock carb on my 429 Ford engine in my '46 truck. I started it yesterday and while it was on the choke it ran fine, as soon as it came off choke it wouldn't idle. It will die as soon as I restart it unless you're pumping the gas. It was last run about two weeks ago and was o.k. then. I have checked the fuel filter and it's clear, I fooled with the Idle mixture screws to the pint I had them five turns out with no change. I guess something in the idle curcuit is amiss, time for a rebuild? any other things to check first?

chimp koose · September 07, 2009, 02:34:09 AM

massive vacuum leak?Did a vacuum line /plug fall off?

phat46 · September 07, 2009, 08:01:14 AM

Quote from: "chimp koose"massive vacuum leak?Did a vacuum line /plug fall off?

That's actually the first thing I checked for, everythings o.k. as far as vac lines and i checked the holddown bolts, they are tight. I think I'm gonna get a rebuild kit and go through the carb, even when it was running O.K. the idle mixture screws didn't seem to make any difference as far as tuning the carb.

C9 · September 07, 2009, 08:25:29 AM

Bad or stuck PCV valve?

phat46 · September 07, 2009, 09:25:53 AM

Quote from: "C9"Bad or stuck PCV valve?

Didn't think of that, I'll take a look.....

wayne petty · September 07, 2009, 12:04:39 PM

is the intake stock?? does it have an adaptor plate under the carb??? is the adaptor to manifold gasket gone bad?

did you install power brakes??? did the booster blow out? that will cause enough vacuum leak to drive you nuts

is there anything holding the secondary butterflys part way open?? just enough to kill the idle.. but not enough to pull fuel over?

phat46 · September 07, 2009, 12:57:24 PM

Quote from: "wayne petty"is the intake stock?? does it have an adaptor plate under the carb??? is the adaptor to manifold gasket gone bad?

did you install power brakes??? did the booster blow out? that will cause enough vacuum leak to drive you nuts

is there anything holding the secondary butterflys part way open?? just enough to kill the idle.. but not enough to pull fuel over?

It has an aftermarket aluminum mainifold, I can't keep it running to check for vacuum leaks under carb. Nothing obvious by looking at it.

No power brakes

I'll have to check the secondary butterflies...Thanks

enjenjo · September 07, 2009, 02:45:37 PM

Quoteis there anything holding the secondary butterflys part way open?? just enough to kill the idle.. but not enough to pull fuel over?

Common on Edelbroc carbs. If they set a lot, the secondary throttle sticks just barely open.

phat46 · September 07, 2009, 05:30:57 PM

PCV valve is free, secondaries are closed tight....

Carnut · September 07, 2009, 05:50:26 PM

When I've had similar problems with my AFB's and Edlebrocks it's been the bowls drying up and gum being left in jets and circuit passages.

39deluxe · September 08, 2009, 11:56:21 AM

Quote from: "Carnut"When I've had similar problems with my AFB's and Edelbrocks it's been the bowls drying up and gum being left in jets and circuit passages.

That would be my guess too since you cant find any vacuum leak or hanging butterflys. Always use fuel stabilizer when you are going to let one set for a period of time and be sure to run it long enough to get it clear through the carb before shutting it off.

Tom

phat46 · September 19, 2009, 04:25:28 PM

Update: I took the carb apart and cleaned it, although it wasn't really dirty like some Iv'e seen, there was no gunk or residue in there. That seems to have made all the difference, I had to turn the idle screw out about one and ahalf turns to slow it down and i could go another half turn I think. I lost the off idle stumble it had and it idles very nicely now. I took it out for a test dirve and when i came back to the house I was grinning and telling my wife how good it runs now. She said she could tell....I gotta do my burnouts farther from home I guess... :oops:

Mikej · September 21, 2009, 04:05:27 PM

Quote from: "phat46"Update: I took the carb apart and cleaned it, although it wasn't really dirty like some Iv'e seen, there was no gunk or residue in there. That seems to have made all the difference, I had to turn the idle screw out about one and ahalf turns to slow it down and i could go another half turn I think. I lost the off idle stumble it had and it idles very nicely now. I took it out for a test dirve and when i came back to the house I was grinning and telling my wife how good it runs now. She said she could tell....I gotta do my burnouts farther from home I guess... :oops:

That's the way I test my work to. My wife enjoys a good burnout...............no...really....

Its also the way I test the tires for wear. When they're new I can't barely spin them but I keep testing

them until they smoke really good.