Vaccuum Secondaries...not opening????

[Grim Reaper]

Originally Posted by skillet

Chevy High Performance March 2004 has a good article on Q-jet entitled "Special Q." It mentioned that "the air-door tension (on the back barrels) must be properly adjusted. If it's too tight, the door won't open under load and the engine will strain. If it's too loose and the door opens too quickly, it will bog. If you feel some light-to-moderate resistance when pushing the door open, the adjustment should be about right." If the front of the carb was facing north, the screw would be at the southeast corner of the carb, corner passenger side as it's mounted. On mine(1969), an allen set screw should be loosened before the other screw is adjusted. I tinkered with mine, but never really noticed much difference. Still learning.

Yep and screwing up that door setting is where Quadra "BOG" moniker came from.

If your pulling steep hills with no Ping or spark knock...They are opening. Leave it hte hell alone.