fuel pressure, airfile and gauge

hi, Im having a tuff time getting my fuel pressure to read correctly. I used AirEd to look up entry 545 and all i get is a hex entry, which i dont know what to do with. I made a new XML gauge and in the sim it is nearly pegged. So i used a stocker and get the same reading. how do i fix it? can i divide the XML entry in half (would get me close) or do i adjust the air file entry. help. everything else in the airfiles seems good. or do i just adjust my gauge bitmap to fit my actual readings???joe