I've had a fuel problem, and it started about a week after I replaced the fuel gauge and brought it back down to 39. I was running 55psi for about 10 days before.
Fuel pressure is lost after 2 minutes of shutting the car down. When I go to start it when warm, it will hesitate for a split second, and than start. There is a misfire at idle, and it has a sporatic misfire when cruising... almost like a hiccup, the whole car jerks and than keeps on going. Check engine light has come on, but I cannot pull any codes.
The regulator is a Kirban AFPR. I don't think that's the problem, because there's no fuel coming out of the vacuum when the pressure is dropping, and I don't see or smell any fuel around the regulator.
None of those would cause the fuel to be ending up in my cylinders causing a hesitating startup. My pump is a Walbro 255lph, and the filter was just replaced 3 weeks ago.