As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JUST PRIOR TO DESCENT FL310 LEFT ENGINE SURGED ALL PARAMETERS. PERFORMED ENGINE RUN IAW MM 71-00-00. AT HIGHER POWER SETTINGS EEC UNLATCHED ENGINES REMAINED EVEN. EEC LATCHED BOTH ENGINES REMAINED EVEN. NO FAULTS NOTED WITH LEFT ENGINE. (M)