I think 2Sav is on the right track. The summit pump was junk (Go figure, lol), and so is his guage, (which, and correct me if I'm wrong Steve, came from Jeg;s or Summit as well?).
My opinion, which is like assholes, everyone has one, I think you were getting false readings in the first place. I'm gonna peruse your posts to see where you installed the guage, but I would assume a faulty guage. No Way a mechanical can produce that (Short of a custom deal).
Yeah, maybe a Nascar pump, but c'mon, Mine works O/T to do 7 psi with two carbs and mine is a race Pump!
Steve, I would do this. And this is just me as I'm in retail and given todays economy. Call Summit and tell them their pump is junk (be an asshole, I know you can). They'll offer to replace it, but you don't want that Chinese junk. And i'd tell them just that, then ask for a manager. Then ask for HIS boss. Keep bitching (I know you can) until you get what you want. I guarantee you can get a good pump for free and over nited. (I would push for a new guage too, as that seems to be the root of all the evil)
Just me, and everyone, do NOT come into my store this way, I'm smarter than that, lol
Ray