Car was running fine, stopped at the store, shut it off, went in, came back out, started up fine, got out on the road and it acted like i was running out of gas. Got it back to the parking lot and it died. It would start back up for a second but then just sputter and die. All the fuses and relays are good. Opened up valve on fuel rail and shorted relay, fuel shot out valve, so pump works. Now I'm stumped. Any thoughts?