quadrabog not working
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Joined: Dec 2006
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quadrabog not working
I put a new jet performance Quadrajet on my newly rebuilt 427 and now cannot get the secondaries to work correctly. As soon as the secondaries are engaged the motor coughs and bogs. What do I need to do?
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Quadrajets are not a one size/setup fits all carb.
Not much of a chance for success with commercially rebuilt Quadrajets.http://forums.corvetteforum.com/show...ght=commercial
Not much of a chance for success with commercially rebuilt Quadrajets.http://forums.corvetteforum.com/show...ght=commercial
Team Owner
Joined: Feb 2005
Posts: 32,519
Likes: 1
From: central America
St. Jude Donor '08-'09
Get Lars' papers or talk to Lars about your setup.
If you don't know who Lars is, read the link, and you'll learn that he is the man when it comes to quadrajets.
PM me if you want me to send you the papers.
If you don't know who Lars is, read the link, and you'll learn that he is the man when it comes to quadrajets.
PM me if you want me to send you the papers.
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
Usually the "bog" occurs because the upper secondary air valves open too quickly,..more noticable on cars with automatic trannies. Many will mis-diagnose the bog and do all sorts of things to their q-jet to "fix" it, only making everything much worse.
There's an adjustment on the passenger's side of the carb, near the upper air valve shaft. You need a small short screw-driver and a small allen wrench (3/32"?). You loosen the little allen head screw which is a set screw, then tighten with your small screw-driver, the small adjusting screw (it points up and hard to see) about a 1/4 of a turn. Then retighten the set screw with your allen wrench. The adjusting screw is spring loaded so don't let go of it while the set-screw is loose. It's rare you'd need more than a half turn either way on the adjusting screw. In your case, you need slower opening of the air valves so tighten the adjusting screw. Again, start with a quarter of turn.
Drive and adjust from there.
There's an adjustment on the passenger's side of the carb, near the upper air valve shaft. You need a small short screw-driver and a small allen wrench (3/32"?). You loosen the little allen head screw which is a set screw, then tighten with your small screw-driver, the small adjusting screw (it points up and hard to see) about a 1/4 of a turn. Then retighten the set screw with your allen wrench. The adjusting screw is spring loaded so don't let go of it while the set-screw is loose. It's rare you'd need more than a half turn either way on the adjusting screw. In your case, you need slower opening of the air valves so tighten the adjusting screw. Again, start with a quarter of turn.
Drive and adjust from there.
Last edited by 73, Dark Blue 454; Oct 30, 2007 at 11:58 AM.
Drifting
Joined: May 2005
Posts: 1,629
Likes: 4
From: Somers CT
I recently re-did a 77 Q-Jet for my motor using the advice and techniques from Cliff Ruggles book. You can do allot to these carbs to make them perform much better on a particular motor setup. I'm MORE than happy with the performance gains over the stock carb that I achieved. He sells kits and is exceptionally helpful with questions.
http://www.cliffshighperformance.com/
Bill
http://www.cliffshighperformance.com/
Bill
