1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Where is the air fuel mixture screw?

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Old 10-04-02, 06:59 PM
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Where is the air fuel mixture screw?

I think my fuel mixture is running rich. So where do I find the adjustment screw?

Thanks.
Old 10-04-02, 09:11 PM
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if you look at your engine from the driver side, than look down near the base of the carb, there is a little screw down there. I hturned mine to about 3 1/2 turns out from all the way down. tinda tinkerd between 3 and 4 turns, found were it felt the best.
Old 10-04-02, 09:52 PM
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The screw is supposed to be covered with a silver-colored cap.
Old 10-04-02, 11:40 PM
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I beleive that is IDLE mixture, dont tink it adjust anything but the idle right guys? Not sure there?
Old 10-04-02, 11:44 PM
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Originally posted by MIKE-P-28
I beleive that is IDLE mixture, dont tink it adjust anything but the idle right guys? Not sure there?
Give this man a Vanilla Coke... yeah... it's the Idle air mixture screw, so if you're having problems in the top end of your car, that's most likely not going to help...

Jeff
Old 10-05-02, 12:35 AM
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what?! than were is the air/fuel screw!?!?!! no wonder it isnt really helping in the top end!?!?!?! Damn
Old 10-05-02, 01:56 AM
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Originally posted by 851stgen12a
what?! than were is the air/fuel screw!?!?!! no wonder it isnt really helping in the top end!?!?!?! Damn
To alter the a/f mixtures you need to change the jets in the carby. In the mean time keep searching for that elusive a/f screw.
Old 10-05-02, 11:40 AM
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lol, well I feel rather stupid. I will keep looking, tell you if I find anything!! JK
Old 10-05-02, 02:01 PM
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this is the air/fuel mix screw
Old 10-05-02, 02:08 PM
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Originally posted by Pittdp

this is the air/fuel mix screw
No thats the idle mixture screw
Old 10-05-02, 02:20 PM
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Originally posted by MIKE-P-28


No thats the idle mixture screw
damn you get another vanilla coke now i guess
Old 10-05-02, 02:24 PM
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LOL what the hell is it?

I was wondering how something that far down from the carb could adjust the air/fuel mixture....
Old 10-05-02, 02:28 PM
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Originally posted by gamble302

damn you get another vanilla coke now i guess
Give me beer or give me death
Old 10-05-02, 02:31 PM
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Originally posted by MIKE-P-28


Give me beer or give me death
im only 18, i dont drink
Old 10-05-02, 02:57 PM
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Never stopped me Get older friends LOL
Old 10-05-02, 03:56 PM
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Originally posted by 851stgen12a
LOL what the hell is it?

I was wondering how something that far down from the carb could adjust the air/fuel mixture....
Like Mike-P-28 said it's the idle mixture screw. It basically allows for fine tuning of the idle mixture before it enters the air-flow just below the throttle butterflies. That's why it's located right at the bottom of the carb.
Old 10-05-02, 08:41 PM
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how do i get the pos cap off? :| the silver colored cap on the screw that is..
Old 10-05-02, 10:47 PM
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it will pull off if you can get a pair of waterpump pliers or regular pliers down there. PITA. I think it got mine off when the carb was out though.

So is this the screw that goes 3 1/2 turns out?

What about the other flatter screw located below the accel. pump? Is there an ideal or stock position for that one too?
Old 10-06-02, 02:19 AM
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The flatter screw is your idle air bleed set screw (Idle screw) Ideal position for that one is right around 750 RPM at idle
Old 10-06-02, 01:34 PM
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mine was about 18 turns out. set it to 3 1/2 and runs much better now obviously
Old 10-06-02, 07:22 PM
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Yeah thats a good intial setting, screw it in all the way and back it out about 3 turns.
Old 02-08-04, 07:30 PM
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Still no word on this mysterious A/F screw? I've having problems now too with my car running VERY rich. My exhaust is pretty dark and I'm getting about 100-120 miles to a FULL TANK OF GAS WHICH IS NOT GOOD FOR ME OR MY WALLET! ....so, I help or a picture is appreciated. My bro has my haynes, so don't tell me to look in that.

Help is appreciated, also I apologize if I revive other carb related threads that are long dead. heh
Old 02-09-04, 03:59 PM
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Nevermind, I found the damn thing. Little bitch is hard to see. heh
Old 02-09-04, 04:29 PM
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Yep, you found it. Is that the stupidest place to put an idle adjust or what? Even with a long screwdriver it's hard to get to and then your hand gets burned by the oil filter.

After hours of discovery and practice, I'm just getting to the point where I can adjust the thing in a reasonable amount of time, but it takes a lot of patience and very good hands to feel the screw head without being able to see it.

Of course, I've still got the rat's nest, reason enough, I suppose, to get rid of it.

Ray
Old 02-09-04, 04:43 PM
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The idle screw isn't too hard to see, that's right there, sticking out and easy to get to with a long screwdriver. The Mixture on the other hand is hidden deeper underneath the brackets on the right (closer to the firewall) And all those vacuum lines are a pain to work around. Anyone have any suggestions on what to use to make it easier to adjust.

My car is running so rich is ridiculous. Rough start up when cold and the exhaust is darker than what I think it should be and I am going through a 16 gallon tank of gas in about 110 miles.


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