Ran fine , went in store and when I came out car started but ran rough for a minute then died . I listened for fuel pump and it didn't come on . I replaced the pump and filter and still won't start . I borrowed a code reader and it had p0300 . Rented a fuel pressure gauge and it didn't register any pressure . I hooked it up before and after the fuel filter with no reading but when I unhooked the fuel lines fuel comes out at a decent rate . I checked fuses and grounds and all were good . When I try and look online there is a dozen things people say it could be . I'm looking for a priority order of things it could be . Any help is greatly appreciated . Thank you in advance .