Are my secondaries working? (Video)

[79dentside]

Hey guys, I apologize if this is a stupid question or if I am clearly missing something, but I opened the air flap on the top and fully opened the throttle linkage and the secondaries do not open. I wedged it open for the purpose of a video. Is this normal? I’ve noticed it’s not peppy while driving, just off the line.

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Thanks

 

[Rickf]

needs to be running, secondaries are vacuum operated.

 

[79dentside]

needs to be running, secondaries are vacuum operated.

Makes sense. Why do the back flaps move a little then? They move ever so slightly by the linkage.

 

[Blue Ox]

They're not true vacuum secondaries. The throttle plates are mechanical, the air door responds to air flow. There's something wrong with your linkage.

 

[75gmck25]

The secondary throttle plates inside the body should be moving as the linkage moves to full throttle. The top air doors that you blocked open are the vacuum/demand part of the carburetor.

There is also a secondary lockout that is connected to the choke mechanism. It locks the secondaries until the choke is off. However, it should be off because you are holding the choke open manually.

Bruce

 

[79dentside]

Thank you all, I thought something was up.... I’m really hoping someone didn’t put the wrong intake on this thing. I didn’t think to check the lockout on the passenger side. Also, those back secondaries and pretty wide, they may not have clearance to open now that I look at my intake. I’ll go tinker later and see what I find.

Thanks for confirming that something was wrong. I saw a linkage going to the secondaries, but wasn’t sure if there was some type of vacuum actuation or not.

 

[79dentside]

Just ran out and messed around. The secondary lockout is NOT obstructing the secondaries.

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I also pivoted the secondaries from that pin you see, and they fully open, so it’s not a situation where the butterflies are hitting the intake.

How do I adjust the linkage on the drivers side? That seems to be my culprit.

 

[bedwards]

Before you break or adjust something that's not broke, read up on the quadrajet. Your linkage looks fine to me.
You should feel and hear the secondaries when they kick in under a load. You really can't tell much with it not running.
http://www.crankshaftcoalition.com/wiki/How_to_rebuild_a_Rochester_Quadrajet_4MV_carburetor
https://73-87.com/7387garage/drivetrain/myqjet.htm
http://www.mako.com.au/buick/html/qjet_tips.htm

 

[Blue Ox]

Did you try disconnecting the throttle cable and whatever other attachments from the throttle lever and moving it? Maybe you're just not getting full travel because something is interfering or hung up. Hard to see in the video.

 

[79dentside]

Found “A” solution, not sure if it was the problem.... The 4 barrels open 100% now. I am finally able to hear the famous moan of a Quadrajet. Even at full throttle, the rod was NOT long enough, so I stretched the angle out until it opened them.

Before:

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After:

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**I do NOT recommend bending stuff like I did... After looking at Google images, it looks like I bent it out of the factory angle.... I just did it to see and it worked.

This could be VERY dangerous as I had initially bent the horizontal flat part of the rod and by doing that, it shortened the length, as a result, it cracked the secondaries open at idle. So I started it and it was idling at 3,000 rpm..... Not good. Still not sure what the problem was, could be that someone stuck the wrong rod in??? I don’t know, this truck has been played with a lot over the years so nothing surprises me.

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