Well it finally happened- six months after replacing the lift pump with the vulcan lines/ fittings I finally managed to drag fp down to 12. It was kinda weird I was in no hurry to go to work so I'm just idling down the road in 4th and I look down and I'm sitting at 12 psi. I give it throttle, let off and its still sitting at 12. Then once I have the truck parked the fp never came back up. When I went to start the truck later it shot straight up to 15+ at idle and was 14 at cruise, but I am now able to pull fp down to 12 on a roll.

I assume I'm seeing the FF showing some miles. About 6k on it currently. When do you start thinking about changing the FF, when you can hit 10 or so? I thought FF's were supposed to be good for 15k?

 

Mods might want to move this to the 24v section for better exposure?
I ussually change mine with a 1-2lb drop but I measure pre an post filter to see the drop.
You may have picked up some bad fuel, it dosent take much to kill a filter.
Time can kill a filter too as diesel has a bacteria that grows in it that can plug a filter.
Change it out and see if the psi comes back

 

I just noticed that too