So when I turn my car off on my 2013 G37x and go to my fuel pump and remove the quick connect fitting I have 0 fuel pressure immediately after turning off my vehicle. I have a misfire on cylinder 4 which has led me to my fueling as my issue. I have already checked compression swapped coils/plugs all the other things to lead me to this including swapping out fuel injectors. My question is what is most likely my issue if the car is not holding fuel pressure when I turn the key off. Ive swapped fuel pumps from my 2010 G37X and still the same issue. The other G has fuel pressure and it comes out of the line. Is this a sending unit issue or my fuel pressure regulator? Infiniti gurus help me out here. Thx

 

Have you checked pump output while it's on? IE, pressure when running?