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#1 |
Before and After
Join Date: Feb 2000
Location: Leduc, Alberta CANADA
Posts: 632
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QuadraJet Tuning
Are there any tuning tips for Q-Jets? I have bee fiddleing around with the Air/Fuel screws, but it still burns very rich, I dont want to go less than 1 turn out from the seat, just in case it leans out too much. Is there anything else that adjusts the fuel mixture other than the two screws on the bottom of the carb? I will get it rebuilt if it helps, is there anything to change once it is apart that would help this situation? I hate throwing money away when it could go elsewhere in my truck.
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Not Grandpa's C-20 anymore... 383 Stroker 425HP, 485Ft/Lbs Lowered 3.5" Front / 5" Rear 66,000 miles. Alberta, CANADA |
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#2 |
Before and After
Join Date: Feb 2000
Location: Leduc, Alberta CANADA
Posts: 632
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Just thought of something....
Do you think my choke is stuck? I have th kind that actuates from the Intake maniold.
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Not Grandpa's C-20 anymore... 383 Stroker 425HP, 485Ft/Lbs Lowered 3.5" Front / 5" Rear 66,000 miles. Alberta, CANADA |
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#3 |
Cantankerous Geezer
Join Date: Aug 2002
Location: Bel Aire, KS
Posts: 6,264
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1-1/2 turns out is a good starting point. Prepare to back them out farther, if needed.
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Fred There is no such thing as too much cam...just not enough engine. ![]() |
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#4 |
CCRider
Join Date: Feb 2000
Location: Olive Branch,MS,USA
Posts: 2,232
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The idle mixture screws that you are adjusting do just that, adjust the air fuel mixture at idle. Once you touch the gas pedal, they don't do anything. On most carbs you would need to buy jets kits and do all kind of experimenting. On a quadrajet you can ussally get it right on buy adjusting the float. The same reason that this carb pisses everyone off, is the same reason that GM could use this carb on every thing from overhead six pontiacs to big blocks with few changes. This carb is super sensative to float level and moving the float on this carb 1/16 of an inch makes a MAJOR difference.
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72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS |
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#5 |
Before and After
Join Date: Feb 2000
Location: Leduc, Alberta CANADA
Posts: 632
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Does backing them out cause a richer or leaner mixture?
Richer = more fuel less air, causing gasy smelling smoke out of the exaust.
__________________
Not Grandpa's C-20 anymore... 383 Stroker 425HP, 485Ft/Lbs Lowered 3.5" Front / 5" Rear 66,000 miles. Alberta, CANADA |
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