I believe I am missing the spring that opens the other half of the barrels on my carb. I know one side connects to the silver piece that you use to flip the flap open but where does the other end go? Posted in the engine section and just realized there was a carb section, sorry for the double post.

 

You're missing the vacuum break and linkage that limits the opening rate of the secondary air valve.

 

How much will that set me back to fix? Will I be ok driving for 2 days before I can get it into the shop to redo it or am I better just slapping a holley on there? Im not sure which one I should be looking at but I have a 77 chevy 350 block completely machined with keith black flattop pistons bored .30 over, stage 2 cam, 305 HO heads machined.

 

It won't have any effect on the car unless you open the throttle enough to open the secondaries. Even then at most it will bog (hesitate) a little as the secondaries open.

 

So do I just need a new vaccumn line then? Carbs are past my knowledge lol. Im missing a line on the front right corner to im guessing controls emissions.

 

I didn't read what Aperion said carefully enough. Some carbs have a vacuum break (vacuum servo) on the back of the carb, some on the front (and a very few with both back and front). The 3rd gen q-jets I've seen all have the vacuum break on the front. You are missing the linkage between the vacuum break on the front of the carb, and the air valve shaft toward the back of the carb. The holes that each end of the link go into are clearly visible in the pic you posted.

The primary function of the vacuum break is to slightly open the choke flap when the car is initially started cold. The choke should be fully closed as you start the car, but then needs to be opened slightly as the engine starts to run so it isn't overly rich. Slightly modifying what else Aperion said, the vacuum break also limits the initial opening of the secondary AV to prevent bog (hesitation) when you first go wide open throttle.

 

See those two Torx-head screws on the rear/pass. side of the carb that aren't holding anything in place? Those screws used to hold the rear vacuum break in place. You're missing that rear vacuum break (which you can buy) and the rod that connects it with the secondary air valve arm (which yuo can't buy).

To the junkyard with you, my friend! No, not to get rid of your car or your carb, but to swipe the parts you need. Just look at a bunch of QJets on late 70s/early 80s trucks and you'll find the parts you need.

 

Alright ill pull the number off the carb and find which vacuum break I need to pick up and hit the yard for the secondary air valve which should be semi easy to find at these yards. I noticed the vacuum switch has nothing connected to it either, along with the other piece that looks like it except has 3 nozzles. Im guessing one is emissions of some sort?

 

Went to the junkyard. The only parts motor they had that had a quadrajet is a 69 chevy pickup truck. As long as its a rear mount vacuum break it should work shouldnt it?

 

Pre-emissions Qjets are different from the emissions-era ones. I don't know if that extends to the linkages.

 

Found a junkyard that has a few quadrajets they say and some newer holleys that I might just swap over and save myself the headache.

 

Found the piece I need and picked it up. Do i just put it on and go or is there adjusting needed?

 

They are usually pretty close just putting them on, Adjustment is accomplished by slightly BENDING the linkage. An air valve vacuum break should hold the air valves in their full-closed position when vacuum is applied to it (like idling in the driveway). A tiny bit of slop is the linkage is what I shoot for in the full-retracted postion. So you can just push the air valves open a degree or two with your finger before the linkage prevents it from opening further.