Setup: 71 buick GS with everything stock Problem: secondary only opens 1 out of 30 time I try to make em to. Hi O Buick gurus :grin: Ok if I understand my carburator correcty, the big plate that is the closest to the firewall would be my secondary butterfly. If I play with it I notice that the rod on the passenger side seems to jam on the carb's housing itself. I'm pretty sure that's my problem. Thing is, its a stock setup it should be woking no ? Anyone knows how to fix this ? Max
You might check for your choke linkage binding, or the choke not opening fully........just that last little bit of choke will prevent the secondaries from opening. I went through the same thing here, and finally just adjusted my choke rod (bent it) so the choke is opened all the way real soon after starting.....just warm. Mike
Max, The big butterflies at the rear of the carburetor are the secondary air valves. The secondary throttle blades are at the bottom of the carb. The secondary throttle blades open mechanically when the primary throttle blades are nearing full opening. There is a choke lockout that prevents the secondary throttle blades from opening when the choke is on, like Mike said. The secondary air valves are held closed at idle by the primary vacuum break on the passenger side front of the carb. The air valves will only open, when the engine demands the additional airflow, and when the vacuum break relaxes and allows them to gradually open. If you are watching the airvalves while increasing the engine speed, you will probably not see the airvalves open. If you very rapidly open the throttle, you may see the airvalves move a bit. As manifold vacuum drops towards 0, the vacuum break releases it's grip on the airvalves, and the vacuum created under the airvalves will tip them in. Again you may not be able to see this by simply working the throttle. Under low speed conditions, it is possible for the secondary throttle blades to be open and the airvalves to be shut. They only open when the engine needs the additional airflow.
Ok so my option are either try and betn the rod out of the way or file down the casting ? Or maybe i could try and make a new rod. Anyway thanks for the feed back. Max
Q-Jet Woes Hey Max did you get your Q-Jet up to "Snuff" yet ? I did alot of research here on " V8" and several other sites . I also used Doug Roe's Q-Jet Book. First of all.. Do you have to have a " Stock " appearing carb ? If not I could give you a few tricks that I did on my Q-Jet that worked very well . Let me know .
I bent the rod a little on the front butterfly (choke rod). the one that runs from the coil on the intake manifold to the top of the carb. It has a little bend in it, which i straightened just a little. Mike
Well I applied a temporary fix until I take the carb out (stock original Q-Jet) for rebuilt. I just used a Tie-strap to disable the choke entirely. Car a little harder to start, but beside that it never ran better. Don't know if choke components come with regular rebuilt kits, but the old ones will head for the trash can soon. Oh and another question: I need the carburator # in order to order my rebuild kit. Where is it ? Max
