Cliff's Quadrajet Parts and Rebuild Kits
Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: wiguy on April 17, 2012, 08:45:15 AM
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Rebuilt the carb over the winter using recipe #1 for my mild 350. I have been told the popping out the exhaust at idle was caused by a lean condition. I opened up the idle tubes, have 76 jets with 44 rods. The apt screw was bottomed out when I rebuilt it, since then I've backed it out about a turn and a half, idle screws are out 5 turns and the the problem still persists. After running at WOT it will idle and accelerate from a stop with out the popping. I checked the timing and it's spot on. Any ideas would be welcome.
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What is the carburetor number, and engine specs?.....Cliff
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carb # 17059203 79 corvette L-48 motor. PO had it rebuilt and over bored, but original heads mild cam, headers, true dual exhaust, no cat, no egr
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Still using the large main airbleeds?
Might need more idle fuel (larger idle tubes/down channel), and raise the APT up to 3-4 turns.
Where is the float set at, and do you have one of our kits installed?.......Cliff
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Carb was rebuilt using one of your kits, including new throttle shaft bushings. It has the large primary bleed. The popping is worse than before I rebuilt it which is why I'm wondering if the problem was too rich rather than too lean. I'll raise the APT and see what that does. Thanks
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oops, the float level was set per the instructions in your book, 3/8 or 1/4 I don't remember off the top of my head.
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played with the apt from 0 to 6 turns out and it didn't make a difference. I may have to find someone with an AF meter.
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Finally! raised the float 1/16 and the problem resolved
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Good news!....Cliff