Secondaries not opening?

At first I thought it was the vacuum diaphragm so I took it apart, and it was torn so I replaced it. My secondaries still do not open up at WOT though. I have a holley (#1850) 600cfm with electric choke. I also tried changing it out to a holley (#3310) 750DP with electric choke, and the secondaries would not open up with that one either. The 750DP does have other problems with it, but I was simply trying to see if I could get the secondaries to open with it. I am not completely sure of how they work, but I didn't think it could be a vacuum leak because my power brakes still work.

So I have a couple of questions.

1. What could be the cause of the secondaries not opening up?

2. My 750DP will not idle down past about 1200RPM without dying, I have adjusted and adjusted it, I even replaced the power valve in it to see if that would help, but it did not. I am at a loss with what to do, all of the gaskets are fine on it. If it was adjusted to lean would this cause the problem? I just need help with this one, if you have any questions or want more information please ask.