Rochester carb assistance

[itbrokeagain]

My cousin just bought a 79 Vette with a 4BBL Rochester. The secondaries are not opening. If I put a screw driver in there I cant open them. All the linkage seems to be connected and moving. Any tricks or do I need to pull it and try to get them working? This car sat for about 3 years.

 

[Sponge Bob]

yes tear it appart and soak it with carb cleaner or seafoam

 

[stroked88]

do you mean the vaccuum secondaries, or the throttle blades?

 

[Sideshow]

On some Q-jets the secondaries are inhibited from opening by a cam in the linkage. It's hard to say without the carb in front of me but I believe this cam is partially operated by the choke pull-off diaphragm. If I remember correctly, the secondaries won't open if the choke is on, or if the choke pull-off diaphram is faulty. Does the high idle detent and choke work correctly?

If the answer is no, in my opinion, the likely cause is the choke pull-off diaphram or vaccume line. This is a great carb and well worth rebuilding.

Here's a cool article with good pictures: http://www.powerblocktv.com/magazine/?pub=735fa32c&page=18