2001 7.3 / very old fuel 2 years old maybe 3 years
 

Well my pops past on and my mom wont sell the truck even gets notes left on the windshield every other week asking to sell it for 15k ? My bro inlaw is bugging for it but im his only son and I deserve it if anyone deserves it .
51k miles and it purrs .
It sat for 1 - 1/2 years untill the tires popped sitting there with 80 % tread . We got 5 new kumuo tires a few weeks back , it has a half of a tank of fuel . I ran it yestetday and was pretty stinky but it show no sings of issues .
I know big rigs can sit for a year and a half with no problems .
This fuel is at least 2 years old and maybe even 3 years old .
Should i run it thru or drain it out for the injectors sake ?
Or dump addettive in it .

I would dump it and add PDS additive, just something to raise the cetain rating! help clean out injectors.

I'd siphon a sample out and see what it looks like, it can get a black algae in it. If it's just greenish translucent I'd run it.

Diesel is interesting fuel. I would run it.

I run every combustible fluid imaginable in my IDI, but I'd be a little leery of any questionable fuel in the PS. At the very least pop the filter cover and see what the stuff looks like. If it looks and smells ok I'd at least top off with fresh stuff and a good additive. If the exhaust smells abnormal something's not right and it might just be the old fuel. It would suck to damage a set of expensive injectors because of some old fuel. If you happen to be near my area I'll burn it in my IDI to get rid of it. I assume you could take it to an auto parts store that takes waste oil and dispose of it there.

It'll also need the oil & filter changed, possibly the coolant and other fluids; the sooner the better.