Edelbrock Performer 800/AFB clone trouble

[462CID]

I am getting a big hesitation on hard acceleration. I have checked out everything from the plugs to the carb, and while the plugs were not fouled, one of my float bowls was way high, the other way low. I reset the heights, and the big hesitation is now a moderate one. I rebuilt the carb, and yes, new filter :grin: . No high rpm gas starvation, so I don't think it's the pump. I also get a hesistation while cornering sometimes, so my suspicion is that the floats are still to blame (yes I replaced them during the rebuild).

Any other suggestions? What are the float droop and heights supposed to be on this carb? I used the rebuild kit instructions to the letter, but something is very definitely wrong. Other than that, the carb meters gas like a champ.

I am pulling 19" Hg (with a very small leak) so I really don't think it's vacuum, and the engine is timed correctly. I use a K&N air filter, re-oiled this year. I replaced the acelerator pump, and verified it's proper function on the bench. I have no secondary shaft binding, and full travel on the throttle cable.

Any help??

I am going to again try and contact John Osbourne, and ask him to redo my 800 cfm QJet...until that gets done, I must drive on this carb, and not only is it robbing me of power, I think fuel consumption is up, too.:confused: I don't rebuild my Qjet myself because it's a little too fiddly. I have rebuilt AFBs/Edelbrock clones about a dozen times with no troubles ever, but this is killing me, and I can't see how it's anything but fuel. When you drive the car, it even feels like a fuel problem. Y'all know what I mean:) Big hesitation, then I chirp the tires without shifting gears.

[67COUPE 340-4V]

Hi, The Edlebrock web site has specs on the float level and other tuning stuff. I had a hesitation with my new carter because my fuel filter was right on the manifold causing the fuel to boil and hestitate and stall. I moved the fuel lines around and now its fine. If you have three holes on the acc. pump linkage, you may want to try moving to a different hole(closer to the carb is a lager fuel shot. The pump shooter can also be changed to a larger diameter. Metering rods, spings and jets are also easy to change. Good Luck to you! Mark

[462CID]

Thanks, Mark.

I should have mentioned: I've run this carb for 3 years in a daily driver and never had an issue, I haven't changed metering at all, and the accelerator pump has always been ok at the hole it is in now. I am running a large can filter behind the carb, and easily 2" above the manifold. I use steel fuel line routed in the stock location up the front of the block, and then it is suspended away from the manifold, beside the valve cover. I also used the correct Edelbrock rebuild kit.

I guess I was hoping that somebody has found out that the factory spec for the floats is a little off, and that they have a better height to try...it's beginning to look as if something isn't quite right with the carb in general, but I don't know all that much technical info about problems on an AFB/AFB clone like this...is there a plug that's staked that can cause problems? Is an air bleed known to get clogged, or something like that? I just don't know, but it's the simplest carb, I rebuilt a the same one but a 750 while it was on the manifold...this is making me scratch my head big time, because I have checked and re-checked everything I can think of, and no luck.
But thanks for the suggestions.