2001 ls s-10 blazer wont start

hey all new here . have a problem. was going out the road the other day and my blazer shut off just quit. stopped lifted the hood checked for spark and it had spark , checked the fuel rail valve and plenty of pressure. so it still didnt start, i towed it home hooked up my scanner no codes so i checked for spark again and it still had spark , checked fuel pressure still had fuel still wouldnt start. so i let it set for a while , a few hours, still wouldnt start. went into the garage for a battery charger came back out and she fired right up. ran fine . went out this morning and it wouldnt start. if anyone could please help it would be appreciated. im assumming it must be some sensor of somekind or maybe a loose wire but i thought the obd would have scanned that. thanks for reading by the way its an 01 ls s-10 blazer 4.3