I have a Sc400 1994, one morning hard to crank , then cranked hard to keep running without holding foot on gas , clean throttle body and remove battery cables and let sit for about thirty minutes, ran fine later that day wont stay runninng after cranking, replace fuel pump new, replace fuel filter new, still not running, pull codes replace mass air flow new, cranksensor new, bought a used ecm same problem dtc codes are 13, 24, 31, 71 any ideas . . . . .