I wouldn't run a used unit either. Did you apply pressure to the BPV's trigger/signal line before drawing the conclusion it isn't closing?
The Bosch BPVs are decent units. There are two commonly used, the less expensive one will handle about 9 or 10 psi on a regular basis and the more expensive one will handle 14 - 16psi regularly without failure. I don't have the part numbers handy. Both are used by Saab.
Can't even get the IC piping to stay together and you're already setting race dates...
and
.... Supra owner through and through.