I have 2 Edelbrock AFBs on my Hemi they have the original size tops on them and the factory progresive linkage. The problem I seem to be having is a lean serge just of idle at aprox 30 mph. If I increase the sdeed to 40 mph it clears up. I think the carb is not providing enough fuel through the transition slots under very light throttle. Could this be my problem and if so can I open up the idle fuel circut to provide more fuel to the transition slots? Thanks Tim

is that the same very light throttle amount at 30 and 40 MPH? I'm thinking not. It'd help to know the vacuum at both of those places. I would try a richer rod that has a slightly thinner "cruise" step. I'm assuming you ain't into the power circuit which is why I ask what in hg vacuum you have at those 2 points and what springs are in there. An Edelbrock performer strip kit with rods/jets close to the same diameter as what you have now will work if you do not have an AFB strip kit available

Have you got the choke adjusted where it's open all the way when warm?
Pump arm-shot adjusted optimal?
Float level-drop?
Fuel pressure?
Ignition timing optimal?
Valves adjusted?

Any and all of the above will cause an off-idle stumble if out of wack..

I wouldn't mess with the idle/fuel circuit unless every other area is checked first.

I've never had to go that far with AFBs..

Fred

I dont know the vacum at the two different speeds but I can tell you if you bring the motor just of idle it runs a little rough and you cover the choke tower with your hand the motor levels out. When I first got it going it was doing this at higher revs to but I fixed this with the next size up jets in the stip kit. If you look at the venturies when the motor is running as you slowly open the throttle it runs rough until it gets up to a speed were it starts to pull some fuel through the main jets then it levels out. There is no choke on this carb, the initial timming is 14 and total is 32, as far as the pump shot it is very responsive but when you hold the throtle steady at 1300 rpm you got no pump shot. Thanks Tim

I would try another size up on the primary jets myself. Pump shot won't effect steady rpm quality.

Sheldon

The pump shot works fine when you mash it at 1300 rpm the issue is when the car is just coasting at light throttle before the carb starts pulling fuel through the main circut it seems the transition slots are not providing enough fuel. If you hold the engine at a steady 1300 rpm in neutral it runs a bit rough if you put your hand over the carb cuting of some of the air the motor levels out this to me is a sign it is lean. If you bring the revs up to 2000 you can see fuel coming out of the main circut and the problem goes away. The issue I am having is a lean serge at very light throttle. The carbs work great in every other sense no flat spots no hesitation and no serging at higher speeds. My question would be can I get more fuel to the tranition slots?

Update, After removing the venturi blocks in preperation to enlarge the idle chanel restrictors I found one of them was blocked with debris. I cleared the blockage and reinstalled them the car runs a lot nicer now. I will now fine tune it with the O2 sensors. Thanks for all the replies.