Q Jet question

[dion]

Been having a problem with the secondaires not opening up. The Carb hasn't really been dialed in yet, I'm supposed to take it in this week.
What causes this and how can I fix it myself?

[ckhd]

First thing I'd check is that WOT is really WOT. With the pickup off, have someone push the pedal all the way down, then see if you can make it go farther by moving the linkage on the carb. If the throttle cable is out of adjustment, pushing the pedal to the floor might only give you 3/4 throttle, or 7/8, or whatever less that full throttle-- which is required to open the secondary butterflies.

Also, there is a vacuum diaphragm that holds the top butterflies closed (it's on the passenger side of the carb). Make sure this thing moves in and out correctly. It's also possible that if it's plugged into the wrong place (vacuum-wise) that it won't open. It will only open when there is a loss of vacuum, and the throttle is at WOT. If it's plugged into the wrong port on the carb, or is tied into the vacuum canister somehow, it might keep the top butterflies closed.

If I remember right, there is also linkage that will prevent the secondaries from being opened even at WOT. Can't remember the specifics. Maybe if the fast-idle cam is set, or maybe if the choke is on, or I dunno.

Typically, the first thing I mentioned is the problem.

[Project1970]

It's the choke linkage that blocks the secondaries.

[dion]

Okay, found the problem. The secondary doors were stuck on the little stopper that keeps the doors shut. There are little nicks right where both stoppers touch the doors so it went up past it a little and got stuck.

[ckhd]

Cool. Have you gone out and tested the secondaries? Any smoke? Can you see your gas-guage drop when you are using them?

[dion]

No smoke, it's running good. It was fine up until a couple of days ago, it still needs some fine tuning though.
The MPG really isn't that bad, my Edelbrock was a lot worse.