Hey everyone. I am having an issue. I rebuilt the Holley 2280 carb, previous owner put in new plug wires and plugs, fuel pump, etc.

The idle mixture screws I put back in exactly as they were when I took them out (the whole bottom them out and turn them back so many turns thing). The van runs way better than I got it, but I didn't have it long before redoing a bunch of stuff so I don't recall if it had the stumbling issue.

Anyway, it idles fine, but accelerating from a stop, the van will hesitate (I actually had it die on me once) unless I put my foot into it a bit more...almost like there is a fuel issue? I am not exactly sure what is wrong. I was thinking the float level may be a bit too low? But other than that, I am not sure. Under power it does fine. It is just when accelerating from a stop.

Any help would be great. I do work on cars but I am kind of learning as I go. this car doesn't have the lean burn stuff.. just the distro with vac advance with a 318 2 barrel.

Thanks in advance!! It is no fun to put your foot into it when you are trying to go, lol

 

In my opinion rebuilding carburetors is skilled labor. A partially blocked passage or a sticky float maybe a gasket is faulty maybe your accelerator pump spring is weak or another twenty other things could be causing your stumble. You could be chasing the reason for your stumble for weeks possibly longer.


Professionals who rebuild carburetors for a living can spot problems in seconds/minutes while you and I will still be learning how to spot issues. I have rebuilt about thirty or so carbs over my 46 years with a 50% success rate so no longer do I bother rebuilding carbs as the time I spent trying to diagnose one of my bad rebuilts was not worth it IMHO.


New Carter AFBs are a couple hundred bucks at Autozone or Advanced Auto to me it would be worth a look.

 

It does sound like an accelerator pump out of adjustment.

 

Unscrew your air/fuel mixture screw to max idle, then screw it in 1/2 turn. Then readjust the idle screw. You may need to repeat several times as the butterfly valve inside of the venturi needs to engage the transfer slot at just the right angle/vacuum. And that butterfly valve is "controlled" by the idle screw.

What is your carb? A Carter 2bbl??

And I've lots of experience with a stumble off of idle. It has much to do with that butterfly valve.