What was found
IN CRUISE AT FL350, LT ENG SURGING .3 N1 INCREASING TO .6 N1 FLUXUATION BY THE TIME OF SHUTDOWN IAW QRH. FLUXUATION REFLECTED IN EPR, FF, & OIL PRESS. PER QRH. ENG SHUTDOWN & CREW DECLARED AN EMERGENCY & DIVERTED TO DFW . AFTER LANDING MTX GROUNDED ACFT. PERFORMED LT ENG RUN UP IAW AMM 71-00-00. PERF OPS CHECK OF LT ENG EEC ON & OFF IAW AMM 73-21-07. CONDITION REMAINS, INDICATION FLUCTUATED EITHER EEC ON OR OFF. C/W FIM 71-05 FT 822. INSPECTED ENG OIL CHIP DETECTOR, NO CONTAMINATION. INSPECTED MAIN OIL FILTER, NO CONTAMINATION. R & R TT2 SENSOR IAW AMM 73-21-05 PER FIM 73-21-FT 811. PERFORMED ENG RUNS IAW 71-00-00. ADJUSTED MIN IDLE IAW AMM 71-01-00 TO MATCH TRIM TABLE. OPS CHK GOOD. RETURNED TO SERVICE.