Hey Guys, I've been working on getting a buddies evo up and running. It was sitting for about three months. It ran great before, and now it's on the fritz. The car has an AEM ECU, and a walbro 255 in tank and inline. The car was on the dyno a few days ago and make great power, but after a few pulls it started going lean. We watched fuel pressure go from holding at about 75 psi (47psi base + 28psi under boost) for about 10 pulls to dropping back down to about 50psi after 6k rpms. I measured the voltage at the inline pump and it's at about 14.2v. The intake pump is at 10.4v. It doesn't change at all under any type of load. Does the AEM allow it to change to the higher voltage relay or does it stay at a single stage?

Any thoughts as to what the heck could be going on?