how to adjust lean/richness on a Q-Jet?
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Joined: May 2001
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From: Greenwood, Indiana
Car: 1984 Trans Am
Engine: Vortec 355
Transmission: TH-700R4
Axle/Gears: GM Axles and GM 3.73
how to adjust lean/richness on a Q-Jet?
i think my car is running rich....how would i b able to adjust this?
thanks
thanks
Joined: Mar 2000
Posts: 43,187
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Is it always running rich, or only under certain conditions? Is this a CC or a non-CC carb?
Thread Starter
Supreme Member
iTrader: (1)
Joined: May 2001
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From: Greenwood, Indiana
Car: 1984 Trans Am
Engine: Vortec 355
Transmission: TH-700R4
Axle/Gears: GM Axles and GM 3.73
it seems like its always running rich
and its the stock CC q-jet
and its the stock CC q-jet
check your choke first. Is it worse at startup? that would make it more likely to be choke related, but if it's all the time check your vacuum sensor too. if it is not working or the vacuum line to it is cracked or not existent you will not have any distributor advance and you r fuel curve will be screwed up. When my line was snapped i had horrible driveability problems, failed emmissions, and was getting 12-13 miles to the gallon. It cost me less than 2 bucks to fix it.
Thread Starter
Supreme Member
iTrader: (1)
Joined: May 2001
Posts: 1,638
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From: Greenwood, Indiana
Car: 1984 Trans Am
Engine: Vortec 355
Transmission: TH-700R4
Axle/Gears: GM Axles and GM 3.73
yah its worse on start up
and is that vacuum that you are talking about at the back of the carb...cuz that line doesnt seems to come off really easily so maybe it is messed up or something
and my secondaries arent opening all the way...only a little bit.... and i have to basically floor it when i start it up or it will die
as for mpg.....my car seems like it chugs gas no matter what
lol
and is that vacuum that you are talking about at the back of the carb...cuz that line doesnt seems to come off really easily so maybe it is messed up or something
and my secondaries arent opening all the way...only a little bit.... and i have to basically floor it when i start it up or it will die
as for mpg.....my car seems like it chugs gas no matter what
lol
Joined: Mar 2000
Posts: 1,692
Likes: 1
From: Corona
Car: 92 Form, 91 Z28, 89 GTA, 86 Z28
Engine: BP383 vortech, BP383, 5.7 TPI, LG4
Transmission: 4L60e, 700R4, 700R4..
Axle/Gears: 3.27, 2.73
Kinda sounds like the choke pulloff. It is easy to fix if you can find one. Do a search on here to find more about it, but I guarantee it is the problem if you have to keep it floored to keep it running when it is cold.
It is located on the passenger side of the carb and is hooked to the choke linkage.
Trust me on this, it is one of your problems. I had the same thing happen last year.
Later,
Jeremy
It is located on the passenger side of the carb and is hooked to the choke linkage.
Trust me on this, it is one of your problems. I had the same thing happen last year.
Later,
Jeremy
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