s14 sr20 fuel problem

[jp-racing]

i got my FPR at 3.5 bar and when i take off in first and hit the gas and go over 3000 rpm bough down but then it works fine, if i got to second gear it runs fine + if i put the volume up on my sound system you can see the FP gauge jump from 3.5 to 3.0. I think is my FPR but i want to know what your think