65 Mustang
Well-known member
Hey Guys. Does anyone know where I can get information concerning the proper way to adjust the air/fuel ratio for my carburetor (autolite 1100 on a 200 ci engine)? The car is an automatic. Thanks.
Carburetor Adjustment
- Thread starter 65 Mustang
- Start date
Do you just want to adjust the curb idle mixture or do you need the total A/F ratio cruising & WOT.
The best way is use a wideband A/F tester like an innovate.
Shoot for close to 13.0-13.5 at idle, 14.5 cruising & 12.8-13.1 WOT,
The best way is use a wideband A/F tester like an innovate.
Shoot for close to 13.0-13.5 at idle, 14.5 cruising & 12.8-13.1 WOT,
65 Mustang
Well-known member
Thanks for replying. I am mainly looking to adjust the curb idle speed. Although, I would also like to have the air/fuel ratio set to specs as well. The car was stalling at idle to begin with. I adjusted the idle rpm while the car was in drive to 680. I made sure it was under a full load (headlights, blinker, radio on). I took her for a drive today. She ran fine on the way out. On the way back I turned on the headlights. When I made my first stop, she stalled out. Then the car continued to stall the rest of the way home. It stalled as I was making turns. I am not sure if the headlights are to blame and I need to readjust at a higher idle speed. Does it sound like it could be an improper air/fuel ratio?
I would check out your battery such as its up to a full charge & is capable of achieving its full cranking amp rating.
Then see what the alternator is putting out in voltage with headlights off then on.
Adjust the idle mixture screw with a vacuum guage & screw in the mixture screw or out till max vacuum & idle rpm is achieved then screw the mixture to the lean side to get a 15-25 rpm drop, but still retain a smooth idle. This will get you close to the 13.0-13.5 A/F ratio.
If you still have problems check for a vacuum leak??? Advise from there
Then see what the alternator is putting out in voltage with headlights off then on.
Adjust the idle mixture screw with a vacuum guage & screw in the mixture screw or out till max vacuum & idle rpm is achieved then screw the mixture to the lean side to get a 15-25 rpm drop, but still retain a smooth idle. This will get you close to the 13.0-13.5 A/F ratio.
If you still have problems check for a vacuum leak??? Advise from there
65 Mustang
Well-known member
Thanks for the info. If I am adjusting the idle mixture screw with a vacuum gauge, where do I connect the vacuum gauge to? Does it attach to the carburetor and if so where? Do I need to disconnect anything to attach the gauge? Thanks
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