What was found
AFTER TAKEOFF FROM SJC EN ROUTE FOR PHX THE NR 1 ENGINE BEGAN TO SURGE (N1) BETWEEN 85 TO 90 PERCENT AT HIGH POWER LOADS DURING CLIMB AND STRAIGHT AND LEVEL FLIGHT. TURNED BACK TO SJC AND LANDED WITHOUT FURTHER EVENT. MAINTENANCE TROUBLESHOT PER BMM 71-00-42, RAN ENGINES TO TAKEOFF POWER 92.6 PERCENT, ACCELERATION AND DECELERATION WAS SMOOTH, AND ALL PARAMETERS WERE STABLE AND NORMAL. ENGINE RUN ACCOMPLISHED WITH POWER MANAGEMENT CONTROL (PMC) ON AND OFF, NO DEFECTS NOTED.