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Hesitation Problem/66 GT350

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by tommyleea, Oct 11, 2007.

  1. Oct 11, 2007 #1
    tommyleea

    tommyleea Well-Known Member

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    Have a carb question for the experts. I have a slight hesitation when I accelerate from just about any rpm. Just the initial touch of the gas, then it is OK. Seems like it is running lean, because if I apply the choke slightly, it seems to be OK. The accelerator pump appears to be functioning properly. Starts and runs fine except for this one issue. Carb has had the standard rebuild. Nothing modified. 66 GT350. Factory Carb. Thanks

    Tommy
     
    tommyleea, Oct 11, 2007
    tommyleea, Oct 11, 2007
    #1
  2. Oct 12, 2007 #2
    sstcobra

    sstcobra Member

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    Has the engine been rebuilt and how close to stock is the cam? If you have low intake vacuum, you will likely experience a "bog" upon acceleration as you are describing. A vac leak can also cause this. If you have a vac. guage, what does it read at idle?
     
    sstcobra, Oct 12, 2007
    sstcobra, Oct 12, 2007
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  3. Oct 13, 2007 #3
    tommyleea

    tommyleea Well-Known Member

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    Engine hasn't been rebuilt. Has 80K on it. Need to check the vacuum again. It happens just as you touch the accelerator. You don't have to step on it, or floor it. Happens even just sitting in the driveway. I can just feel there is something missing just as I touch the pedal. Then everything is fine. Runs great except for that. Starts at the touch of the key. Thanks for your input.

    Tommy
     
    tommyleea, Oct 13, 2007
    tommyleea, Oct 13, 2007
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  4. Oct 13, 2007 #4
    Bob Gaines

    Bob Gaines Well-Known Member

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    I would check out the accellerator pump in the carb . Wore out spring or leaking. Not squirting enough when you press on the gas . My 2 cents .The best of luck finding the problem.
     
    Bob Gaines, Oct 13, 2007
    Bob Gaines, Oct 13, 2007
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  5. Oct 13, 2007 #5
    Jerry_Moss

    Jerry_Moss Well-Known Member

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    Hi

    Have you checked the float level?

    Bye Jerry
     
    Jerry_Moss, Oct 13, 2007
    Jerry_Moss, Oct 13, 2007
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  6. Oct 14, 2007 #6
    tommyleea

    tommyleea Well-Known Member

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    I see the accelerator pump cam is in the #1 position. Would it help to move it to the #2 position? I set the float initially, but haven't rechecked it. It doesn't have the externally adjustable float, so it is kind of a pain, but I guess I better double check it. Thanks to all for the advice.

    Tommy
     
    tommyleea, Oct 14, 2007
    tommyleea, Oct 14, 2007
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  7. Oct 15, 2007 #7
    rr64

    rr64 Well-Known Member

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    I checked the Holley variable specifications book, #1 is the specified cam position.
     
    rr64, Oct 15, 2007
    rr64, Oct 15, 2007
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  8. Oct 15, 2007 #8
    tommyleea

    tommyleea Well-Known Member

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    Thanks, I guess I'll cross that one off the list.

    Tommy
     
    tommyleea, Oct 15, 2007
    tommyleea, Oct 15, 2007
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