Heres the whole story. I had a couple leaky gaskets on my carb. I rebuilt it using a holley trick kit. put it back on and ran real bad. after setting everything like it was sapposed to be. 1 week later the bad stumble off idle went away.

It has ran fine for 3 months, and over that period of time I developed a very tiny vaccum leak at the rear of the manifold. Not a big leak, just enough to make that high pitch whine and drive you nuts.

So I finally got around to putting new gaskets in, etc. And made sure they had red rtv on the bolt threads, etc. Next thing I know my dad knocked my carb over and left it standing on the secondary bowl for 4 hrs. (I dont know if that had anything to do with problem) put everything on and fired it up, ran crappy just like after I had rebuilt the carb. Even after playing with the timing, nothing helped. But the vacuum leak was gone!

Everyone thought that it was foreign objects plugging things in the carb before. But I have a clear glass fuel filter on and its clean as a whistle.

The exact problem is this, I give it 1/2 throttle when from a stop and it falls flat, and when moving and it hesitates almost as bad. What kills me is I didn't do anything to the stupid carb!
Plus just now drove it home from work, and it didnt want to idle, about 500 and when I put it in park the idle wouldnt come up... And popping out the exhaust like mad. Then I got out and turned up the idle screw a hair (1/16 turn), then grabbed a screwdriver and flashlight, and the idle picked up by itself, up to 1000 from about 450 (I think it saw me coming with the screwdriver!!!) And the popping out the exhaust quit also.

Please help. Anny suggestions? new carb? anything?

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69 Camaro 1977 350
Shift kit, HEI, holley 600, flowmaster delta flow mufflers
http://msnhomepages.talkcity.com/rallyrd/murfys_law

just a guess... but when it was knocked over,how far did it fall if any.needle and seat may have a nick in it now,not seating properly,or float may have gotten bent causing the needle not to seat correctly.too many variables.

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My68Camaro (http://hometown.aol.com/Dougs68Camaro/index.html)
Doug G.
68 Camaro
406 ci.

I have an 800 Holley that was introduced to Mr. Sledge. We keep it around just to show the other carbs what could happen to them if they misbehave. Hmmm, sounds like your float level could be set too high, or the float is sticking. Does the popping and low/rough idle quit after you rev it up a couple of times? Check to see if you have gas dribbling in the carb. If so, that could be your problem. Let us know what you find.

Unstable idle and off-idle hesitation (assuming your accelerator pump linkage is properly adjusted) can also be traced to worn throttle shaft bushings and a blown power valve. Worn bushings cause unstable idle due to intermittent vacuum leakage. Worth looking at, especially if you've had any backfiring.

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JohnZ
'69 Z28 Fathom Green

Did you use any teflon tape anywhere near your fuel system??? If so, you may have injested some and could be hanging up the needle and seat. You'll see fuel dripping in the venturi (refer to prev. post) You may want to pop off the bowls and have a look see, to make sure they are free from junk. and that the floats are in good shape (un bent)
my .02