The general concensus ( and I agree) is that the truck bled down fuel pressure and lost prime because of sitting. This results in 3 problems: 1-you have to re-bleed the system to get fuel back to the injector pump and injectors to create pressure to power the injectors. 2- air in the filter plays **** with the filter and can crap it out fairly quickly. 3- Junk in the tank grows or settles, then is picked up and pushed into your filter further aggravating the filter issue and causing a faster plugged up issue.
Start by changing your filter. You can fill it as full as you can with ATF or diesel fuel. I like ATF because it comes in a bottle already and it helps lube the injectors and pump that have been sitting for a long time.
Then (Mentioned ab0ve) remove the pink wire that connects to the Injector Pump, crack the bleeder on the filter housing and crank for 15-20 seconds. If no fuel comes out, wait 30 seconds to cool the starter and re-crank. Shouldn't take more than once or twice to re-prime the filter.
Once you have fuel to the filter you have 2 options, crank it until it re fills the fill injector lines, which will cause it to stumble, stop, start, stumble, puke, bitch, whine, moan and then eventually smooth out and run.
OR crack 2 or 3 injector lines to help bleed the air faster. If you have somebody helping they can crank while you watch the injectors. If you crack 3 lines (I like to break open 1-3-4 cylinders) you can close them down while cranking, and it should start to run almost immediately once you get the second line tightened.
Once running...try to put some miles on it right away and keep a spare filter around in case it sucks up some more crud while flushing the lines out.
Let us know how it goes!.