View Full Version : 10 turns on a Q-Jet?


Damon23
04-26-2009, 06:59:09 PM
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?

BondoSpecial
04-26-2009, 08:09:05 PM
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

Damon
04-26-2009, 09:52:21 PM
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.

Damon23
04-26-2009, 10:14:23 PM
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.

How does one, a rookie, open up the idle channel restrictions?