Car not starting when hot

[socalsupra]

hi, ive been having some issues lately with starting my 1991 NSX. In the morning it will start no problem but after i drive it for some time and make a couple pit stops sometimes it will just turn over and not want to start. I replaced the fuel pump and obviously use premium gas, its really driving me crazy so i thought i would consult the pros on prime before handing my car over to the dealers and get raped, hopefully you guys can help me out with this, thanks in advance.