Fuel pressure gauge problem


All of a sudden my Autometer FP gauge is pegged at 100psi. One day it was fine, reading 40psi ish, the next day pegged. Any ideas?

. How long has it been since fuel filter was changed ? it could be dirt but more then likely it's not. One of the ways of reading 100 psi is if return line to tank has a partial blockage or a kink so flow would be restricted and cause fuel backup and pressure would go up depending on how much of a restriction there is. If it was a partial blockage before the FPG the pressure would go the other way, probably alot lower then 43psi. Follow the return line back to the gas tank and check for kinks in hardline or rubber hose. Just a thought...........Hopefully it's just a kink, dirt and not you FPG.
I checked the pressure with another gauge and it's 40ish at idle, so it has to be something with the gauge/sending unit.