Quadrajet rebuild kit advice

[Bixter44]

Yeah you’re correct. My problem is that it was warmed up plenty and it’s only the primary choke that’s controlled by the temperature controlled spring. My problem was the secondary choke flaps. I expected the vacuum controlled relay that holds the secondary choke flaps shut to relax from a drop in vacuum when I opened the throttle ie there’s next to no vacuum with an open throttle. Apparently not! I could feel it wanted to go under hard acceleration but was big time starving for air. I Couldn’t simulate it in the driveway though the secondary choke flaps were definitely locked shut. So I disconnected the secondary choke relay from the vacuum source and plugged it. Drives like a rocket! Hmmm

You have a system on the secondaries I never had. Being vacuum operated secondaries, I could check for proper linkage adjustment simply by pulling the choke blades fully open by hand and pushing on the secondaries. They should push open and spring back up. If that worked, then when the engine was running and warmed up, the choke should be wide open and the secondaries free to open when the demand for air was there, when you walked on the throttle. The secondaries tip open because the atmospheric pressure is greater on the outside than underneath the carb with all the pistons sucking for air and fuel. There is an adjustable spring on the secondaries to hold them shut during normal driving. The demand for air would overpower the spring in wide open throttle situations. I had the spring adjusted as light as I could and not have the secondaries come in too soon.In the driveway I could pull the throttle wide open for not even 2 seconds and the secondaries would just start to open. What I didn't have was this vacuum controlled relay you speak of. Most of the q-jets I played with were late '60's carbs.

 

[72ray]

I’ll let the neighbours sleep in and test it in the driveway to see if when I rev it it the point that the secondaries are opened if indeed vacuum is reduced enough to release the pull off and allow the secondary air doors to open (though dampened by the pull off itself)