P0336 Chevrolet

Question

Have replaced fuel pump and crank sensor already, vehicle will run fine then all of sudden will flutter and lose spark, checked for power and ground at crank sensor and is present, 11.89 on green wire continuity to ground on yellow wire, fuel,psi is at spec, have tightened pins at crank sensor connector already, performed wiggle test on harness no change,
Vehicle will run perfect untill issue happens then will flutter and die out, no time limit could be 10 seconds or two hrs,

Answer 1

The CKP green/white wire with key on should be battery voltage, to begin with you have a low battery, check the charging system, at idle it should be 13 to 16 volts.