Greddy Type-S blow off valve problems!

I have a 97 civic EX. I just got finished putting my engine and turbo back into my car. Everything runs great, except I have one little problem. The blow off valve isn't working properly.

When I let off the throttle after boosting, the valve doesn't lift open all the way. It probably lifts up like 2 or 3 mm. And it makes this fluttering noise.

I am pretty sure I am not leaking on a vaccum line somewhere because at idle my boost guage reads 22 psi.

But recently, I had my blow off valve apart for about a month. Do you think the spring could have stretched itself out and that makes it too tough to open up all the way?

I need some suggestions please. :(

thanks in advance,

aj