Holley carb, accelerator pump nozzle question.
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Holley carb, accelerator pump nozzle question.
My 68 is running pretty good with the holley street avenger until you start stomping the gas pedal. There is some huge cam in the motor as it only pulls about 9 inch of vacum at idle. I watch the accelerator pump squirt the gas in when moving the throttle with my hand. It starts to squirt gas in immediatley, but I get a mild to wicked intake backfire depending on how hard I stomp it. I think this means I need bigger NOZZLES for the pump. What do you think.
Also, even with the electric choke, it runs like crap till it warms up. Is this related to the big cam?? The electric choke operates normally and I have played with the "heat" adjustment (The one that adjusts when the choke starts to open as the engine warms up) . It goes from bad to worse.
Thanks,
--marc
Also, even with the electric choke, it runs like crap till it warms up. Is this related to the big cam?? The electric choke operates normally and I have played with the "heat" adjustment (The one that adjusts when the choke starts to open as the engine warms up) . It goes from bad to worse.
Thanks,
--marc
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From: Calif.
Re: Holley carb, accelerator pump nozzle question. (BigBadOrange)
Usually the shooters are changed in size (bigger) to correct a momentary lean condition in the intake when you go from off-idle to WOT. You know, it idles fine but it bogs for a second when you put your foot in it and then it goes like hell.
Could the backfiring condition be cured with bigger shooters? I really don't know. Possibly. And it doesn't cost much to try. Lots of times, though, backfiring is timing-related, either ignition or valve. Hard to tell without seeing/hearing it. It could be a lean backfire.
As for the choke? Well, you're in Las Vegas. I know it gets colder'nell there sometimes but you may not need a choke at all. Try adjusting it so the choke valve stays open all the time and see what happens. Can't hurt.
[Modified by The Dude, 2:31 PM 11/12/2003]
[Modified by The Dude, 4:40 PM 11/12/2003]
Could the backfiring condition be cured with bigger shooters? I really don't know. Possibly. And it doesn't cost much to try. Lots of times, though, backfiring is timing-related, either ignition or valve. Hard to tell without seeing/hearing it. It could be a lean backfire.
As for the choke? Well, you're in Las Vegas. I know it gets colder'nell there sometimes but you may not need a choke at all. Try adjusting it so the choke valve stays open all the time and see what happens. Can't hurt.
[Modified by The Dude, 2:31 PM 11/12/2003]
[Modified by The Dude, 4:40 PM 11/12/2003]
