Q-jet problems
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Car: 86 Camaro
Engine: 79 350 carbed
Transmission: TH-350
Axle/Gears: 3.73 posi
Q-jet problems
I have been having a problem as far as I can tell with my Q-jet. It is a 1979 non computer controlled q-jet determined by the numbers and was rebuilt buy a friend a year ago. It also came with my 350 that I bought. Just FYI I only know so much about carbs so far. But like everything that I have done with this car I learned and this is why I am looking to this site.
Anyway what is happening when I try getting on the gas the engine trys to cut out at first. Then I have to back off and it struggles to keep going up in the RPMs. Judging by the smoke I believe it is running rich. Here is a video I took of it a few months ago before the winter hit.
http://s39.photobucket.com/albums/e1...amaroMovie.flv
A friend (also only knows only so much) and I tried leaning it out without much help. Also while searching on here for answers I have found that q-jets can only handle 6psi of fuel. Is this right? I did buy a fuel pump that did 6.5 to 8 max but it said that it wouldn't need a regulator.
What I am trying to figure out is maybe it was rebuilt wrong or there is something that I have set wrong on it. I would appreciate any help that I can get.
Anyway what is happening when I try getting on the gas the engine trys to cut out at first. Then I have to back off and it struggles to keep going up in the RPMs. Judging by the smoke I believe it is running rich. Here is a video I took of it a few months ago before the winter hit.
http://s39.photobucket.com/albums/e1...amaroMovie.flv
A friend (also only knows only so much) and I tried leaning it out without much help. Also while searching on here for answers I have found that q-jets can only handle 6psi of fuel. Is this right? I did buy a fuel pump that did 6.5 to 8 max but it said that it wouldn't need a regulator.
What I am trying to figure out is maybe it was rebuilt wrong or there is something that I have set wrong on it. I would appreciate any help that I can get.
Last edited by iggy89; 01-18-2009 at 09:51 PM.
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Car: 1982 Trans-Am
Engine: 355 w/ ported 416s
Transmission: T10, hurst shifter
Axle/Gears: 10 bolt, true-trac, 3.73
Re: Q-jet problems
I can't view the video here at work, so i'll go by a few common problems:
- Check pump shot. Look down your primary blades and flick the throttle with your hand. Make sure you can see dual fuel jets shooting out. You can do this with the air cleaner removed, car off, and holding the choke blade open
- Check to make sure you have enough tension in the secondary air valve. With car off, push your finger into the secondary air valve. Does it SNAP shut, or slowly close, or hang open?
- Finally, the power piston maybe not be adjusted correctly. Your friend might have "tightened" the power piston screw, rather then adjusting it. If the first two points I listed check out, then adjust this. You need to remove the air horn (top plate of carburetor), and adjust this screw. This involves 11 screws, and removal of the choke plate actuator rod and acc pump actuator rod. Kinda tricky, so do this last.
- Check pump shot. Look down your primary blades and flick the throttle with your hand. Make sure you can see dual fuel jets shooting out. You can do this with the air cleaner removed, car off, and holding the choke blade open
- Check to make sure you have enough tension in the secondary air valve. With car off, push your finger into the secondary air valve. Does it SNAP shut, or slowly close, or hang open?
- Finally, the power piston maybe not be adjusted correctly. Your friend might have "tightened" the power piston screw, rather then adjusting it. If the first two points I listed check out, then adjust this. You need to remove the air horn (top plate of carburetor), and adjust this screw. This involves 11 screws, and removal of the choke plate actuator rod and acc pump actuator rod. Kinda tricky, so do this last.
#3
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Car: 86 Camaro
Engine: 79 350 carbed
Transmission: TH-350
Axle/Gears: 3.73 posi
Re: Q-jet problems
Thanks for the help! I will have to wait to check it out tomorrow. It ended up being a longer day at work and I should have time tomorrow night.
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