The truck has been running great aside from the rough idle/miss. Just got back from the coast. The truck did great. The next day I went out to start it and it would just shut off when letting off the throttle instead of returning to idle.. I figured the IP finally gave out , or the metering valve was sticky. After a few minutes I fired it back up and it was back to normal. I let it sit over night and checked the fuel filter in the morning and it was full. I pulled the return check valve and it was clear , no junk in it , and moved freely. I then pulled the top of the IP to look for signs of a failure and to check the metering valve. The fuel was clean , zero junk in it. The metering valve moved freely.. So I tossed it back on and started poking around at other stuff. I Sprayed some soapy water around the glow plugs and injectors and ended up finding 3 glow plugs that weren't sealing , so I fixed those. It still has that rough idle.. The only thing I can think of is either the IP is failing , or there is one or more injectors not sealing due to carbon build up that I didn't clean very well. But wouldn't it be blowing back up the threads and bubbling like the glow plugs ? My next plan is to pull the injectors , thoroughly clean the seats , replace IP with a spare and hope that fixes it.