[JL8Jeff]

OK, let me explain this the way I thought it works. I'm probably wrong so correct me if I am. The fpr "sets" the fuel pressure at a specific level. Let's say stock is 13 lbs. So your TBI is allowing 13 lbs of fuel pressure to the injectors at all times. The computer tells the injectors to stay open longer or shorter depending on the throttle position. So you now have a set limit on how much fuel it can flow based on the 13 lbs of pressure and the injector pulse width. An adjustble fpr allows you to adjust that pressure between 8-15 lbs say. So you set it at 15 lbs and obviously get more flow at WOT. The vrfpr automatically adjusts the fuel pressure from 8-18 lbs depending on the vacuum signal so WOT would be giving you 18 lbs of pressure which should be flowing more fuel. I know several people have measured the vrfpr at WOT at 18 lbs so that's where I'm getting that number. Now, is there a fuel pressure sensor somewhere in the TBI that the computer reads and can be programmed? If so, I'm not aware of it.