Diesel Bombers - 04 Duramax Trouble

Hello new member here. Great site been following for years. 2004 Duramax 6.6 300k miles. Injectors replaced at 240k. Only other fuel related repairs was fuel filter housing. Headed to work truck ran fine first 10 miles then started to act hesitant and sputtering. Stopped and grabbed fuel filter from Napa figured this could be it since it was slightly over do. Left still running like crap stopped at red light then truck shut off. While cranking small amount of white smoke and truck fired up. Continued approximately 6 miles truck dies again with no luck of firing back up. Proceeded to change fuel filter road side all said and done truck would not start. Getting heavy white smoke while cranking and would hit after 6-8 seconds of continuous cranking and die again. Bleed system once more and put pressure on primer bulb and same result. I'm thinking with putting pressure to the fuel system using the primer that's where it was trying to start. Was unable to pull any codes due to location but threw a low rail pressure code 3-4 weeks ago reset it and had no problems. No mods to truck bone stock. Thanks for any help in advance.