apologize if this has already been posted or is not the correct place I'm very new to this form just trying to find some help.... Got a 96 7.3 that belongs to my dad but I've been doing all the work on it he got it from a guy that said he kept up with the maintenance on it but I don't quite believe him I think all they did was use it to tow a fifth wheel around and then parked it for five and a half years straight let it sit and rott. when he got it the tanks were internally rusted to s*** and it had a couple other small issues I pulled the front tank filled it with muriatic acid and gravel try to get as much rust out as I could ended up putting a small inline filter before the main filter seeing as though it's a mechanical pump so there's no filtration before the pump itself well all the work I've done to it so far was I replaced the turbo pedestal and get a ebpv delete pedestal and got a KC turbos balanced component assembly and rebuilt the h-pop had a starting issue after rebuilding the h-pop the IPR took a s*** took a couple days to figure out what was causing it to not start ended up getting one from AutoZone got it fired up and running had a issue with it running like dog s*** when he tried to drive turns out my dad had cut new fuel lines for on the fuel filter bowl well he cut the return fuel line to the high pressure side of the fuel pump little too long and it was kinking and not letting enough fuel flow to the high pressure side of the pump.. figured that out and she was running like a dream. so last week I went up to my dad's house to borrow his truck to go borrow quads for my wife's family. from his house I drove the truck close to 50 miles one way to pick up the quads and then close to 40 miles back to my house with trailer with four quads on it ran like a dream cruising 75 mph barely turning 22 2300 RPM next morning went out picked up my father stepmother drove probably close to 30 40 plus miles out to the desert to go riding the truck felt a little off about halfway there but not enough to really raise suspicion when we were leaving started noticing it running a little rougher couldn't exactly describe it just that feeling you get when you're driving a vehicle enough that something's not quite right well about 20 miles down the road felt like it completely dropped a cylinder pulled over for a second try to look it over couldn't see anything standing out no check engine light made it maybe another 6 miles down the road before it felt like it literally dropped cylinder after cylinder all the way down to one last cylinder then it just shut down when it cranked it sounded like literally one cylinder was firing it would crank normal single fire crank normal single fire but would not start ended up going to my house picking up my crown Vic towing the trailer with it and getting a tow truck for the f250. to be completely honest I was planning on towing truck and trailer with my car but I'm also not the brightest crayon in the box anyway next day went over to work on it and wanted to crank it to see if it was still doing it well it ended up firing up but you can tell it feels like it's dead on a cylinder when you hold it at about a thousand RPM you can really feel it at idle it's not as prominent well come today he had ordered new valve cover gaskets cuz he had a burnt pin on one (glow plug pin) so I replaced both valve cover gaskets and soldered in all new pigtails same thing does it no matter which tank you switch it to it has good fuel pressure and it's definitely picking up fuel I've checked the bowl the tank tried checking the IPR no smoke black nor white/ grey I don't have the best scanner I have an sctx4 tuner for my car but I can check gauges and read codes with it I've checked over absolutely everything I possibly can with everything I know and everything I can find on the internet any help or ideas would be greatly appreciated

 

It sounds stupid but I get the feeling you got some bad fuel. I can't explain it but that's what my gut is telling me. Try running a hose from your lift pump to a fuel can (with differrent, new fuel obviously) and see if anything changes.

 

I kinda already have tried different fuel I filled the rear tank that day (that one has a functioning fuel gauge) the front tank has had about a half to maby full tand since the last time I was working on it I tried switching tanks with no change

 

check the suction hose again for a geed seal, you might be getting air in the fuel