On my LG4 Trans Am, I recently swaped the stock cam, changed the timing chain, did some mild headwork, and changed all the gaskets. Upon completing this work I discovered my coil and ignition module were both bad probably from being in the winter cold for some time. With these new parts in place, I decided to take the ol' bird for a spin and wouldn't you know it, the secondaries don't open! So when I floor it from a stop, it just bogs down and then redlines at about 2250 rpms. I can keep my foot all the way down for as long as I want and it will actually start slowing down a little. My friend tried to help me by adjusting the spring on the pulloff, but he just looked at the thing and said it was busted. He had a similar problem on his 86 iroc and all he needed was a little spring adjustment. My question is, is it the choke pulloff? If so how much, and if not, then what the hell could it be? If I accelerate with about half throttle the car goes and shifts fine. When the car is running, it is almost impossible to push the secondaries down by hand or by the pulloff lever. Help me please i'm new.

 

When the car is idling, the choke pull-off should be holding the secondary air valve closed - that's its job. When you floor it, it is supposed to hold it closed momentarily to keep it from bogging, releasing it as vacuum drops - there is a small hole in the vacuum nipple on the pull-off so the vacuum on the diaphragm is not released too quickly. Then, as air demand dictates, the tension on the AV spring will be slowly overcome, allowing the AV to open (if adjusted correctly, that is).

The adjustment on the pull-off itself (I assume he adjusted the spring-loaded screw attached to the pull-off arm) is intended to vary the amount the pull-off opens the choke butterfly immediately after the car starts when cold. It has absolutely nothing to do with the secondaries.

The bogging you describe could be from the secondaries opening too quickly. But, that usually is only momentary, so you may have something else going on here. It is possible with the new cam and head work that your secondaries are now too lean, so it will never "get over it" until new rods & hanger are put in. Or, you may have a problem with your ignition, such as timing, or the new parts are bad (wouldn't be the first time that happened to somebody).

 

When I recently took my air horn off to tune my carb, I found the brass pick-up tubes laying in the float bowl. So I was getting all that air and no gas. Just something you might want to check if you can't find anything else. I had similar symptoms, but my engine is stock so I don't require much gas anyway.