WHAT FUEL PRESURE?

No the pressure doesnt increase when you hit the throttle, if its decreasing very much it means your fuel pump isnt keeping up. I had that problem when i bought 30lb injectors and tried to run the stock pump, everytime i hit the gas the pressure would drop drastically!
 
The pressure should initially dip for a second and then (if you went to WOT) it comes back up higher than it was at idle (by about 5 PSIG).

Good luck.