Qjet Question

[tj310]

Originally Posted by Robert Simpson

I am having a problem with my Q-jet on my footbrake street car and I could use some advice on how to fix it. I have a nova street car with a sbc/t350 combo that I drive and bracket race. It has a stock valve body with a shift kit and I use a Q-jet. I leave at 16-1700 and it flashes to around 25-2800 and it shifts on its own if left in drive or second. It runs low 12's to high 11's. The problem that I have just started to experience is if I have caught someone early in the run and try to pedal the car it starts to slow down like you took your foot off the gas! But it is on the floor. On this particular run I pedaled once at about 1000' and lost .30sec,12mph and lost the rd! The engine makes a different noise like it is straining but still running but just not pulling. Any idea what this might be in the carb? Could the secondary flap close and get stuck in the closed position? Any idea what this is and how to fix it? I have not modified the linkages at all, and only have done the usual things to rebuild and set it up to run on the car and leave clean without a bog etc. Any advice would be appreciated. Thank you

The secondary air flap is controlled by the forward located choke pull (air valve dash pot / secondary dampener ) . This will not allow the flap to open after a high vacuum for a second , so it sounds like normal operation . The size of the air bleed restriction inside the pip controls the time it takes to open .
Got this from Doug Roe' s book Rochester carburation H.P. Books
...Trevor