As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE EN ROUTE FROM SAN TO LAX, NR 1 ENGINE TORQUE BEGAN TO SURGE AND AIRCRAFT BEGAN TO YAW BACK AND FORTH. FOLLOWED QRH AND SELECT EEC MANUAL PER QRH. FOUR TO FIVE MINUTES LATER NR 1 ENGINE BEGAN TO SURGE AGAIN WITH WIDER PARAMETER SWINGS. ELECTRONIC FUEL CONTROL FAILURE. CHECKLIST CALLED FOR ENGINE SHUTDOWN. SHUTDOWN & SECURED ENGINE PER THE QRH. DECLARED AN EMERGENCY AND PROCEEDED TO LAX. REMOVED & REPLACED LEFT ENGINE ASSEMBLY IAW MM 71-00-00 & 61-10-03.