do i need to upgrade my fuel pump

[IhaveAcarSickness]

car was fine put the tt chip in and scanmaster and dialed it in ,when i leave hard the fp goes up then it falls on its face,same if im doing 35 45 and hit the gas it acts like i cut the engine off ,i have a 400 watt amp for front and rear speakers maybe its losing voltage ?scanmaster reads 13.2 then goes down to 11 for a second or two .im gonna order the pump and volt booster this week but really are these cars that sensitive with low power? thanks......... sorry all stock except what my sig says

 

[IhaveAcarSickness]

new pump the old was a problem put the old 85 ecm and chip back in it and runs great ...thanks