The collapsing hose theory is the first thing I'd look at. Could also be a plugged up pickup, filth in the bottom of the tanks, etc. If your regulating it down on the output side though, would that not limit the vacuum on the inlet side as well? Just thinking out loud, but mechanical pumps mainly push, so maybe too small of feed lines? I dunno, shot in the dark to me. Dunno why you'd need 14PSI EVER ('Cept maybe Terry). Who the one that said there's a difference between High pressure and High volume? Might apply here methinks! I would think a collapsing hose is an indicator of another problem unless the hoses are real soft.
And Nordie, I'd be dissapointed if you baffle them! I'ma keepin mine open, and that is that! Ran it open in front of 6 Deputy Sherrif's and they didn't seem to care, so, lol.
No Steve, Nordie can't post pics right now, his ex-G/F musta gave him the Computer "Clap" as a going away present.
Ray