What was found
AT APPROX 4000 FT MSL WITH CLIMB THRUST SET AT APPROX 1.57 EPR, THE LT ENG EXHIBITED A LOUD BANG & SHUDDER WITH LOSS OF THRUST SIMILAR TO A COMPRESSOR STALL. EGT DISPLAY TURNED RED & REACHED A MAX VALUE OF 920C. THRUST LEVER WAS IMMEDIATELY RETARDED TO IDLE & THE VIBRATIONS CEASED. ALL OTHER PARAMETERS RETURNED TO NORMAL. FOLLOWED QRH & PER GUIDANCE, LEFT THE ENG RUNNING & RETURNED TO FIELD, LANDING WAS NORMAL. LEFT THRUST REVERSER WAS NOT USED. PERFORMED FIM 75-32 FAULT TREE 824 CORRECTIVE ACTION FOR FAULT CODE 04. RANG WIRES FROM BVCU TO TPU & TO PLA, ALL CHECKED OKAY. IAW FIM ACTIONS REMOVED HP & IP SOLENOID CONNECTOR TO RING SOLENOID COILS. ALL RING BETWEEN 93 OHMS TO 96 OHMS. REINSTALLED HP & IP SOLENOID CONNECTOR IAW WDM 75-51-11. R & R LT ENG INBD HP3 BLEED VLV SEAL PLATE ASSEMBLY IAW AMM 75-32-02. R & R LT ENG TPU IAW MM 75-32-15 PG 401. SEE LOG PG 507093 FOR TPU ADJUSTMENT TEST.