I recently bought a 2001 dodge ram 1500 5.9 liter engine. The truck sat for about a year only being started a handful of times. When I try to start the truck it cranks and cranks and tries to start sometimes but just wont start and it is backfiring through the air breather. I replaced the plugs and wires and put gas treatment in the tank which was about half full, plus I added five gallons of 93 octane gas to the gas that was already in the tank What can I do to get my truck running.
93 octane is going to make it harder to start. That does not have more BTUs or develop more power. It ignites harder to resist spark knock which allows engines to be designed to produce more power, mainly through increased compression ratio.
The first thing to ask is if the battery was run dead or disconnected. If it was, the Engine Computer lost its memory and will have to relearn "minimum throttle". To meet the conditions for that to occur, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the gas pedals. You will also experience stalling at stop signs until the relearn takes place, you may not get the normal "idle flare-up" to 1500 rpm when you start the engine, and you may have to hold the gas pedal down 1/4" to get the engine to start.
That would be related to the battery running down. Why was the truck sitting for a year? If it had a running problem, that might still be what you're fighting. Have you checked for diagnostic fault codes? Do you know how?