It wad running perfectly fine

There id no engine light on only when the key is on acc. Could there still be a code? I dnt have access to a scanner the truck won't start and or run long enough to get anywhr. I can't afford to tow it. I would love to have it scanned. And I appologize for not saying in the frst forrum, the reason ive been checking the ignition system is bc Whn it doesn't start there is no fire at plugs or coil. But when it decides to start weather conditions dont matter or does engine temp, it runs fine. But dies shortly after likeyou turned the key off. No spit n studder just shuts off and doesn't fire. Once I was checking fire it sparked right as the key was released to accessory. But it doesn't do that each time. And the fuel pump is about a year old and primes up fine and holds pressure. I'm certain its not fuel, its fire. What else other tha

n Whts been changed could control fire? Computer? Crank sensor? Ign. Switch? And by the way man. There were no symptoms or warnings before my troubles. Just wouldn't dtart after I parked at Kroger for ten minutes. Thank you for any and all help. Hope I can return the help one day.