Neither my air doors or secondary butterflys on my Q-jet will open. Its an old carb that was transplanted off a 75 Camaro and has been sitting for awhile. Fired the engine uup and gave it healthly amounts of carb cleaner inside and out, plus WD40 on the outside. Vacumn line appears to be OK. Can I fix this or does it need major surgery from the folks at Jet Performance or others. Additionally where should my vac advance to the HEI be plugged into? Thanks

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greg,if the butter flys dont work,must be missing the actuation rod,they should open manually,and the air flaps should open on vacuum,check to see if it has a rod going from the primary throttle linkage,to the secodary butterfly rod,it should,if it does, is it binding?check it out,post back---67rat member #199

[This message has been edited by 67RAT (edited 06-16-2000).]

Greg,
There is a secondary lock out linkage that keeps the secondaries from opening unless the engine is warmed up to the point where the choke is fully open. If it is stuck, it may be keeping the secondary throttle plates from opening. As far as the air valve, it is opened by air flow through the motor. As long as it moves freely by hand, it is probably ok. Some q-jets also have a lock out for the air valve, look carefully and you will find it if it is there. By the way, I have never seen an air valve open on a motor sitting in neutral, no mattter how high you rev it. Without a load on the motor, it will just not pull enough air to open the air valve. By the way, the vacuum line has nothing to do with opening the air valve. However, if the carb has a vacuum choke pull-off and it is not working, it can affect the secondary lock out linkage also. Take the carb off and work everything by hand, paying close attention as to what keeps the secondaries from opening. I think you will find it is just a minor problem or adjustment.
As far as the vacuum advance to the distributor, I would try it first on a straight mainifold vacuum port. Either on the carb or directly on the intake if there is a fitting. Some motors work better with a ported vacuum signal, but in my experience, most HEI's like manifold vacuum.
Hope this helps http://www.chevelles.com/forum/smile.gif

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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

[This message has been edited by BillK (edited 06-16-2000).]

Make sure choke is wide open. Little dogleg link on bottom of carb will stop the secondaries from opening if the choke is not completely open.

Thanks 67RAT,BillK, and tom3. All were very helpful. The Air door actuator rod/lever is mangled causing the door to stick. Will go tomorrow to NAPA and try to get another. After disconnecting the throttle linkage and springs I pulled on the linage and the secondary butterflys opened about 1/4 inch. But with the lever connected to shaft I could open them all the way. Looked in a Haynes Manual that shows to bend the actuator rod to adjust secondary opening. Any comment on that? Also hooked HEI advance to manifold and definetly improved idle and overall response. Can't road test til I get some header clearance problems solved. Should have all under control By tommorrow.
Thanks again guys, Greg

Greg, don;t bend the actuator rod to get them to open more. At WOT, the secondary flaps should be pointing at 1 o'clock, not 12:00 like you'd think. So as long as they do that, leave 'em alone.

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G. Chaas
Gold #62/ACES
67 SS396/(427L88) (http://www.chevelles.com/showroom/chaas1.jpg)

Greg,
I doubt that you will find the lever at NAPA or anywhere else as far as that goes. You probably will have to salvage it off another Q-jet. ALso, like Gene said, Do not be tempted to make the secondaries open any more than they do now, it actually hurts air flow !

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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

Bill, Gene, I understand that the secondarys don't point to 12 o'clock but these suckers only point to about 2:45 as viewed from the passenger side. Choke is open. There is a lever inside of the one the throttle cable is connected to that doesnt engage the secondarys until about 90% of full throttle.Maybe in the last 25 years this thing has been taken apart and bastardized by someone. Im going to take a look at other folks Q-jets and see. Appreciate the help, Greg

greg,to adjust the air flap rate,there is a screw near the flaps to adjust tention,pointer,your air flaps should not open while winging he motor in neutral!---67rat member #199
DONT BEND THE ROD,LEAVE IT BE!

[This message has been edited by 67RAT (edited 06-19-2000).]

Yea Buddy, sounds like you got a near survivor there. Anyway, the secondary throttle plates should not be vertical at full opening. For $16-18 bucks you might get the Q jet book, since it sounds like you might have to go through that sucker with a fine tooth comb.

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G. Chaas
Gold #62/ACES
67 SS396/(427L88) (http://www.chevelles.com/showroom/chaas1.jpg)

I want to thank all of ya'll for the insite but I believe I've got a terminally ill Q-jetas I first suspected. But NAPA did have the air door pull off @$22.50 so that part of the problem is solved. Gene; Have seriously considered by the Q-jet book and might jump on Amazon.com tonight and get it. Have got another problem with hot starts also but will play with it in the next day or two before I post another ?. I'm to old for this stuff, need to stick to chasing sleazy women.