If the pressure guage returns to 0 psi when everything is shutdown and depressured then the guage is probably fine and your problem is most likely the regulator.
Yeah it go back to zero. Another reason I think the gauge is reading right and the problem is the regulator is the fuel pump is rated at 14 lbs. wide open and when I crank the fuel pressure reg. all the way up it goes to 14 lbs. I'm going to a metal meet and when I get back this afternoon I'm going to swap out the regulator.