Q-Jet question
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Instructor
Joined: Feb 2003
Posts: 164
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From: Houston Texas
Q-Jet question
Here we go again. Another thread about the Rochester Quadrajet carburetor.
Yet, I am far from understanding everything about it.
This is about the original carburetor that came on my 1971 LS5, just rebuilt. It works fine (full power, nice idle, as good as it gets gas mileage, etc...) BUT:
It has a hard time getting back to idle. Tends to stick to 1,500 rpm until I gently tap the gas pedal, even when hot. I thought the cable was not sliding well enough, but no. This is not the problem.
Today, I had a fairly long drive and the outside temperature was 92F. The engine would not go back below 2,000 rpm even when tapping the gas pedal. I checked: The cable was not holding it. I even disconnected the solenoid to make sure it won't prevent it to go back to idle.
I removed the air filter. The secondary air valves were closed. If I pushed them open, the rpm dropped to normal. It looked like the choke was not working properly.
I shut the engine off and left it cool about half-an-hour. Started it again. It was working normally... until it got hot again.
Any suggestion or advice?
Yet, I am far from understanding everything about it.
This is about the original carburetor that came on my 1971 LS5, just rebuilt. It works fine (full power, nice idle, as good as it gets gas mileage, etc...) BUT:
It has a hard time getting back to idle. Tends to stick to 1,500 rpm until I gently tap the gas pedal, even when hot. I thought the cable was not sliding well enough, but no. This is not the problem.
Today, I had a fairly long drive and the outside temperature was 92F. The engine would not go back below 2,000 rpm even when tapping the gas pedal. I checked: The cable was not holding it. I even disconnected the solenoid to make sure it won't prevent it to go back to idle.
I removed the air filter. The secondary air valves were closed. If I pushed them open, the rpm dropped to normal. It looked like the choke was not working properly.
I shut the engine off and left it cool about half-an-hour. Started it again. It was working normally... until it got hot again.
Any suggestion or advice?
Last edited by ATHANASE; May 26, 2019 at 07:02 PM.
Team Owner
Joined: Jan 2006
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From: Crossville TN
Take a look at the location of the gasket and/or spacer under the carb, and the location of the carb (on the studs), as well. It is possible that the primary throttle plates are dragging or getting hung up a bit on the gasket/spacer. Just loosen the stud nuts a bit and jostle stuff around. Make sure the primary plates are operating freely.
There is also the possibility of tightening the nuts down too much. They are only supposed to have a few foot-pounds of torque on them. Too much can warp the aluminum throttle plate.
There is also the possibility of tightening the nuts down too much. They are only supposed to have a few foot-pounds of torque on them. Too much can warp the aluminum throttle plate.
Is my vette stock?? HAHA
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is your choke connected or disconnected? is the choke pull off working correctly, its the little plastic vacuum piece on the passengers side
