sounds to me like the thing is stuck, if I understand right your talkin about the ones with the little ball and spring inside? also refered to as a Grainger valve (old turbo dodge trick).

tighten= more boost

loosen=less boost

always start with it loosened all the way, I make these all the time for small boost car's (under 20 PSI) and they work great if they're set up right.

Also if you have it facing the wrong way then you will see the same prob because it becomes a check valve and the wastegate see's no "boost" signal at all. ball side should go towards the vaccum source.

How about some pics so we can see what you've done? it'll help us help you...