10 turns on a Q-Jet?

Discussion in 'Engine Topic' started by Damon23, Apr 26, 2009.

  1. Damon23

    Damon23 Veteran Member

    2,650
    0
    Jan 29, 2006
    Georgia
    I have read where Damon states that the quadrajet likes to be somewhere around 4-4.5 turns. My car(79 Z quadrajet carb) will not run at that setting. It has max vacuum around 17in at 10 turns. It is smooth, no black smoke and no fuel smell. What could be the issue or is there one? And will those screws stop when they are maxed out on turns or will they fall out?
     
    Last edited: Apr 26, 2009
  2. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

    8,699
    0
    Sep 20, 2004
    Southern Maryland
    if you are that far out the springs are probably not keeping the screws preloaded. Qjets are a PITA. You have too lean of an idle from the combination of your idle jets and air bleeds. You can plug the air bleeds if you have them on that model carb and see how it behaves
     
  3. Damon

    Damon Veteran Member

    12,843
    2
    Nov 16, 2000
    Philly area
    They will eventually fall out, but it takes more than 10 turns. Agreed, the spring probably isn't holding any tension on them any more at 10 turns.

    Modified engine (bigger cam)? You'll be lean on the idle circuits most of the time if it's stock. Beyond about 4-5 turns out they stop making any difference. Easiest fix is to open up the idle channel restrictions about 4-5 thou over stock and try it out.
     
  4. Damon23

    Damon23 Veteran Member

    2,650
    0
    Jan 29, 2006
    Georgia
    How does one, a rookie, open up the idle channel restrictions?
     

Share This Page