As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE STARTING ENG #2 SPAR VALVE CLOSED LIGHT ILLUMINATED BRIGHT BLUE AND REMAINED BRIGHT. ENG STABILIZED AT AROUND 48% N1 AND HUNG. DISCONTINUED START. AFTERWARD WE FOUND FUEL SPAR VALVE ENG 2 POPPED. GROUNDED - YES. REPLACED #2 ENG SPAR VALVE ACTUATOR REF B737-800 AMM 28-22-11. PERFORMED ENG #2 SPAR VALVE ELEC CONTROL & INDICATION TEST REF AMM TASK 28-22-00-710-801 OP CHECK NORMAL. ETOPS GROUND VERIFICATION SUCCESSFUL.