Hello my name is Scott,
This concern can be caused by a fuel injector
or copper sealing ring on the bottom of the fuel injector that leaks combustion gas into the fuel system.
What happens is the leaking injector will allow the combustion gas into the fuel system and the pressure will overcome the fuel pressure and slowly push the fuel out of the rail in the head back towards the tank.
The way to check is remove the secondary fuel filter cap, using remote starter
with the key OFF, crank the engine
over watching for bubbles, if there are, a fuel injector is leaking. They way to tell which bank it is, is with a balloon test on each fuel line from the heads at fuel housing, the side that blows the balloon up is the problem side. We normally replace all 4 on the side with the problem, if you don't, it may run okay at first, but the injector usually will fail within a few days.
I suspect #2 is the bad one and starving all the rest.
Any more questions just ask, thanks Scott