Why isn't my BOV "psssssshhhhh'ing"?

[slimguns]

So, I had the flange welded on, checked for leaks, none, mounted BOV, installed vacuum block, fixed leak, no more leaks, connected vac lines, drove, built boost, let off throttle, turbo sputter/surge, no pssssssshhhhhh.

I don't understand. I thought all I had to do was install flange, install BOV, and install the vac line. Did I do something wrong?

TIA,
Slim

[koRnhead]

Where did you run your vacuum line from?

[slimguns]

The line originates from a nipple where the PCV used to be, goes into a vac block, one port then goes to top of BOV.

[1999black3800]

Precision billet 6466 , 2-2500 RPMs

[koRnhead]

I would try a different vacuum source to your block first. While a malfunctioning BOV is a possibility, its doubtful, what brand did you buy? A genuine, or Ebay knock off?

[slimguns]

It was this one:
http://shop.zzperformance.com/store/...Off-Valve.aspx

I turned up my boost control today and it started working. I don't understand why only an extra 2-3 pounds would make a difference but whatever. Thanks guys, maybe it just needed to be broke in.

Slim

[Turbocharged400sbc]

your bov spring may be too strong if it wont open at 2+ psi and the throttle closes

its a balancing act...the spring must be strong enough to not open under all non boost vac conditions....it should only function when your making boost and that pressure effectively reduces the spring force that the valve "see's" and allows it to open...at 0-1psi you may not see it move. that is correct.
if the thing functioned at 0psi then youd have the problem of when ever you let off the gas and decelerate the manifold vac spike will hold the bov open and cause a vacuum leak and allow the motor to suck in unfilter air through the bov.