Intermittent issue here. Back ground….new tank, non venting so canister was deleted, line is capped and zip tied at the TB. Casper’s Hotwire and 340 pump, volts read fine on scan master G during acceleration. Took it to the track and made three 8th mile runs with no issues. Driving 30 miles home, decided to to make a WOT blast near home to confirm boost setting. Nope car almost dies. Try again slower and as boost begins to come in FP drops rapidly. Found my make shift canister capped line was not capped and thought ok that’s the problem…..nope it’s now capped as I mentioned and this is still occurring. I’m not saying I may not have new vacuum line issues after the track, I’ve done a once over and don’t see any blaring hose issues, so where should I start looking? And is FP drop with boost going above 1 psi a clear vacuum line leak issue? Or should I be looking elsewhere? I’m not opposed to replacing the 30+ year old billet fp regulator if needed. Thanks to any replies.