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Search is gonna give me a heart attack.....have an air/fuel mixture ?

Discussion in 'The Garage' started by jakeslim, Jul 11, 2004.

  1. jakeslim

    jakeslim 1/2 ton status

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    How do I adjust the air fuel mixture in my quadrajet(edelbrock)? I need to reduce the fuel at idle since that is what I failed at during smog test....

    thanks,
    Paul
     
  2. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Idle mixture is near the bottom, two screws very close to the base of the carburator on the front.
     
  3. backcountry

    backcountry 1/2 ton status

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    If you have or can borrow a vacuum gage, hook it up and try adjusting to achieve max vacuum with little needle movement.
    /forums/images/graemlins/peace.gif
     
  4. jakeslim

    jakeslim 1/2 ton status

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    thanks Tim and Backcountry /forums/images/graemlins/thumb.gif I went ahead and turned the two screws clockwise about 3/4 turn(one on the passegner front and one on the driver front of carb. It is still starting and idling good, with no missing.

    Please confirm that this is what I do to make it leaner. I wasn't burning my fuel fully enough at idle, so I failed.
     
  5. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Check your ignition timing.
     
  6. backcountry

    backcountry 1/2 ton status

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    [ QUOTE ]
    thanks Tim and Backcountry /forums/images/graemlins/thumb.gif I went ahead and turned the two screws clockwise about 3/4 turn(one on the passegner front and one on the driver front of carb. It is still starting and idling good, with no missing.

    Please confirm that this is what I do to make it leaner. I wasn't burning my fuel fully enough at idle, so I failed.

    [/ QUOTE ]

    Yes, those are the right screws. You want to get it to run smooth with the highest rpm's and vacuum you can achieve. Once you get it set you may have to adjust your idle adjustment screw down some. Best way to achieve this is to use a vacuum gauge. Hook it up to a constant vacuum source on your carb or intake manifold. I use the vacuum port on the carb. On your carb I believe there are two small ones. One will have vacuum all the time and the other only upon acceleration.

    /forums/images/graemlins/peace.gif
     
  7. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    To clean up your idle numbers considerably turn the idle rpm up a little. My old 350 used to put out horrible numbers at 600 rpm, but at 850 it passed with flying colors.

    Our E-test allows a max idle rpm of 1100 rpm...and the higher the idle the less valve overlap and bad numbers you'll get.

    Rene
     

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