vacuum reference on regulator

[67ragtp]

Quick question, the vacuum reference hooked up to my pressure regulator is dropping the fuel pressure to39@idle and 35 psi when I hammer the throttle(it used to go up when I hit the throttle to 42/44. I noticed this after coming in from some cruising, the engine bay was very hot and water temp was good @ 185. As soon as I pulled the vacuum line the pressure sticks to 42 and stays there no matter how much throttle I give it. Any idea whats happening, it almost seems like theres a higher vacuum signal in the throttle body when the blades are opened, dont get it, thought it goes the other way.
The engine seems to run well, seems a little down on power but it was extremely hot out today- Your thoughts? Thanks Rich