COMMUTER LTT HAD AN AIR TURNBACK PLUS 2 TKOF ABORTS BEFORE BEING FERRIED TO MAINT BASE FOR REPAIR.

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ON TKOF FROM LAX RWY 24R AT LIFTOFF; L ENG TORQUE FLUCTUATED APPROX +/- 5 PERCENT. NO OTHER INDICATIONS TO CORRESPOND AT THIS TIME. CLBING THROUGH 1000 FT; TORQUE INCREASED FLUCTUATION +/- 15 PERCENT WITH AT LEAST +/- 1 PERCENT RPM FLUCTUATION AND CORRESPONDING AUDIO AND YAW CHANGES. ASKED TO RETURN TO LAX. LANDED AT LAX WITH NO FURTHER PROBLEMS OR INCIDENTS. WE EXPLAINED THE PROBLEM TO MAINT AND THEY TOOK IT TO BE WORKED ON. 2 HRS LATER WE PICKED THE ACFT UP FROM MAINT AND PREPARED TO LEAVE FOR SNA. (MAINT SAID THEY CLEANED AN OILY CANNON PLUG AND RAN UP THE ENG WITH A GOOD OPS CHK.) L ENG TORQUE CAME UP A LITTLE SLOWER THAN R AND SLOW TO STABILIZE. THROUGH 80 KTS; TORQUE FLUCTUATION APPEARED +/- 15 PERCENT. DID NOT OBSERVE OTHER PARAMETERS; ABORTED TKOF. RETURNED TO GATE AND TURNED IT OVER TO MAINT WITH THE SAME PROBLEM. THEY FELT NOW IT WAS PROBABLY THE TORQUE/TEMP LIMITING COMPUTER; AND PREPARED THE ACFT FOR FERRY FLT TO FAT WITH TTL COMPUTER INOP. I TOLD LCL MAINT THAT IF THIS DID NOT CORRECT THE PROBLEM I WAS NOT GOING ANYWHERE. 4 HRS LATER THE ACFT WAS SET FOR FERRY FLT WITH TTL COMPUTER TURNED OFF. CLRED FOR TKOF AND ADDED PWR. L TORQUE AGAIN CAME UP SLOWER THAN R AND AGAIN THROUGH 80 KTS TORQUE FLUCTUATIONS APPEARED +/- 15 PERCENT. DID NOT OBSERVE OTHER PARAMETERS DUE BEING BUSY WITH TKOF; ABORTED TKOF. MAINT CTL WHO ASKED WHY WE ABORTED A FERRY FLT. AFTER SOME HEATED DISCUSSION; WE DETERMINED THAT THE ORIGINAL MAINT PERSONNEL (CHANGED SHIFTS BY NOW) DID NOT INFORM MAINT CTL ABOUT THE AUDIO AND YAW PROBLEMS. MAINT CTL THOUGHT WE WERE ONLY ABORTING FOR AN INDICATION PROBLEM AND NOT A PERCEIVED REAL PROBLEM. THEY GAVE US A NEW ACFT TO COMPLETE OUR SHIFT. NEXT DAY I INQUIRED AS TO THE STATUS OF THE ACFT. THE AIRPLANE WAS FERRIED UP TO FAT THE FOLLOWING MORNING WHERE THE MAIN MAINT BASE REPLACED A FUEL CTL VALVE.