Plenty of them are kicking around the forums. Try to get and STI BPV, I have tested them to hold well over 22psi.
In terms of testing what you have I'm not to sure if there is an easy way. It doesn't sound like it is a holding pressure issue. IF the bpv is the problem it make have a slight leak or could even be too stiff, maybe seizing up.
Check all the vac lines leading up to the BPV for issues, make sure you are using the larger vac line from the manifold for the BPV signal. Make sure there are no leaks on the recirc hose from the BPV to the intake.