RushRacing401

Ok to start i just got a procharger put on my v6 mustang last week. Everything went in fine and i had a legit shop do all the wrk, they ended up having to customize the intake pipe and the mass air flow sensor because it is none intercooled and it is pushing 8.5 psi. So anyway the same day i got my car back i drove around for a lil then went to start it up again to show a friend and it started up and in like 5 sec died as if it was suffering for sumthin. My engine light came on and the code came up as fuel pressure code. My michanic came out and somehow it just started right back up. now today it did the same thing four days later. the car will turn over but wnt start up i have no clue what is wrong with it does anyone have a clue.