my secondaries are barely opening

the guy at a machine shop said to move the choke linkage a little and see if it does any better.....well i shut the flap on the choke a little bit....and the secondaries did work....but right when i let go they dont work again......what could b messing this up...is it something on the inside or outside?


any help would b greatly appreciated.......thanks!

 

What you're saying doesn't quite make sense. I'd hoped someone else would take a shot at it, but since that hasn't happened, I'll have a go.

There are two ways the choke holds the secondaries closed:
1) When the choke is not fully off, the fast idle cam is up, and a little lever pivots to hold the throttle blades closed. When the choke is fully off, the fast idle cam pushes that lever away and allows the throttle blades to open. I'll assume that isn't what you're talking about.
2) When manifold vacuum is high (such as at idle or only the primaries in use), the choke pull-off holds the secondary air valves closed - this is to keep them from flapping open when you first nail it. The only time vacuum will get low enough for that to release is at WOT and under load. If you can see it release while in the driveway with your head under the hood, it isn't working right.

I'll assume it's this second mode that you're talking about. If so, you probably don't have the problem you think you have.

 

oh
ok well then how would i fix that manifold pressure problem?

 

It's not a problem, it's how things work. The manifold pressure will drop when under load (won't happen rapping the throttle in the driveway), and when RPMs increase enough for the engine to need the additional air flow, the AV will open.