Video: How to get rid of Qjet bog and hesitation

Discussion in 'Wrenchin' Secrets' started by buicks, Jul 14, 2017.

  1. buicks

    buicks Well-Known Member

    I found this video fairly hits all the good points.

  2. Brett Slater

    Brett Slater Super Moderator Staff Member

    As a Q-Jet owner, I have to say that this carb is just WAY to complex. I mean, how much tuning do you really need to do to get it where it needs to be.

    That kind of takes the fun out of it, in my opinion. Which isn't worth much.

    No wonder Holley has stood the test of time.
  3. D.S.R.E.455

    D.S.R.E.455 Active Member

    The adjustability is why i like them, coming from an engine builder/tuner stand point, just slow down the secondary air valve a bit if you have a bog going from primary to secondaries.
    I custom build these and have made over 605hp NA and i love them! Especially the apt carbs from 75-79
    techg8 likes this.
  4. 51wood

    51wood Active Member

    Something to always check on any carb with a bog problem is that the linkage is not the problem. Just a tiny bit of slack that doesn't let the acel. pump actually start working when you hit the pedal will cause a bog. Same for the throttle plates not really opening when you think they are.
  5. Mark Demko

    Mark Demko Well-Known Member

    I get what your saying.
    The same can be said for fuel injection, but everybody seems to covet it:D
    The Q-Jet is a VERY good carb, its a very good fuel metering device, yes it IS more complex than a Holley style carb, and it is the "default" carb, (me included)
    I have come to believe its the Q-Jets lack of a secondary accelerator pump shot to cover the "hole" when the secondaries begin to open, that's why the air valve opening has to be controlled..... slow and steady.
    If they just dump open, theres your "hole" and your bog, until fuel is added.
    At least that's what I theorize:p
    Brett Slater likes this.

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