What was found
NR 1 ENGINE SHUT DOWN WITHOUT CREW ACTION AFTER NORMAL START, DURING PUSHBACK. FUEL VALVE CLOSED LIGHT ILLUMINATED. REMOVED AND REPLACED THE LT FUEL SHUT OFF VALVE IAW MM 28-22-11, LEAK CHECK OKAY. THIS DID NOT FIX THE PROBLEM. FURTHER INVESTIGATION REVEALED TWO WIRES AT THE CONNECTOR FOR THE LEFT FUEL SHUT OFF VALVE BROKEN. REPAIRED BROKEN WIRES AT CONNECTOR, OPS CHECK OKAY. AIRCRAFT RETURNED TO SERVICE.