hi there lads is there any way to tell wot pump is on my 3dr

why im asking is my 3dr has a t34 on it with black 55lb injectors swedish plenum rs 500 intecooler and running only 15psi boost but when i up the boost it starts to splutter and back fire . we have set the AFR to about 12
and i have a fuel pressure gauge unber the bonnet and its at 3 bar and 3.5 bar with the vac pipe of . so im thinking it could be the pump or the wire running the pump . im going to run the fuel pressure gauge into the car and see wot it dose when the car comes on boost should it still be 3 bar ???????? and wot should the volts on the pump on tick over and on boost be showing .. thanks for any help