Truck hasn't been started in a year, then got out
going. It ran for 3 days, now it won't start. It
sounds like it's trying to stay but neve does. It does
have gas in it.
3 days thats just enough time for the fuel pump to suck up the crud from the fuel and plug up or stop working all together, i would recommend taking the fuel filter off and back blow it into a rag and see how much crud you get, if you get a fair amount then you can bet theres more in the pumps strainer.
Search Chevrolet Suburban Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Chevrolet Suburban Experts