General Category > Quadrajet Carb Talk and Tips
Secondary Choke Pull-Off Release Times
Brian B.:
Hi. I have a mild 4000lb performance car; 12.9/105mph. When street driving, I'm trying to completely eliminate a slight hesitation when I stomp on it while cruising at 40mph or so. I've just about solved it making my own metered orifices providing a 2 second release time with 3/4 spring wind-up. Is it possible to completely eliminate this while stomping on it.....and what sort of release times are some of you using for performance applications? Thank you.
Cliff Ruggles:
What is the carburetor part number and does it use the REAR pull-off to hold the secondaries closed?
If so, those are a huge PITA to time correctly. They just hold TOO MUCH air inside them. By the time you get a big enough hole in them to release without a slight delay they are too quick.
Even so they can be made to work, but it takes some effort to get them perfect........
Brian B.:
My carb is #7044270 and is stock for my car. It has not been drilled or messed with other than the pull-off, which controls the secondary air doors. I did upgrade the accelerator pump using your high performance version. The car runs perfect in every area except stomping on it at 40mph.(which is just too fun to stop). 60 foot times are 1.82(good for this car) with drag radials and problem free. Thank you.
Kenth:
I have found the biggest issue with non-responsive secondaries on a 7044270 unit is the air valves.
Replace the un-cut air valves with a set of cut air valves from any other 1967-74 Pontiac Q-jet to solve the issue.
Brian B.:
Thank you. It's very close now. I will try 2 more orifices then try a set of flaps from another carb.
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