A B737-300 THE FIRST FLT AFTER #2 ENG CHANGE EXPERIENCED #2 THROTTLE RESTR TO 90% N1 PWR. SHUTDOWN ENG ON APCH TO TERMINATING ARPT.

Narrative

IN FEB/97; 2 ABC MECHS WERE SENT TO ZZZ TO DO A DYNAMIC RIG OF THE VARIABLE STATOR VANES ON #2 ENG ON A B737-300; DUE TO SLOW ACCELERATION OF THIS ENG. THE ENG FAILED THE ACCELERATION TEST AFTER THE DYNAMIC RIG; SO 2 OTHER MECHS WERE ALSO SENT TO HELP CHANGE THE MAIN ENG CTL. THESE MECHS WERE UNABLE TO COMPLETE THE MAIN ENG CTL CHANGE IN THE ALLOWED TIME PER OUR MAINT MANUAL; SO 3 MORE MECHS WERE SENT TO COMPLETE AND INSPECT THE MAIN ENG CTL INSTALLATION. THE ENG AGAIN FAILED THE ACCELERATION TEST AND IT WAS THEN DECIDED TO CHANGE THE ENG. ALL OF THE MECHS THAT WERE IN ZZZ WERE NOW SENT BACK TO ABC. 6 OTHER MECHS WERE NOW SENT TO ZZZ TO ACCOMPLISH THE ENG CHANGE. THESE MECHS NOW WORKED 24+ HRS STRAIGHT TO COMPLETE THE ENG CHANGE (A PRACTICE AGAINST THE MAINT MANUAL). WHEN THE ACFT LEFT ZZZ ON A REVENUE FLT TO ABC; THE FLC WAS UNABLE TO RETARD #2 ENG BELOW 90% N1 AND HAD TO DO AN INFLT SHUTDOWN ON FINAL APCH INTO ABC. IT WAS DISCOVERED THAT A 10-32 NUT WAS LEFT IN THE THROTTLE BOX; THAT PREVENTED THE FLC FROM RETARDING #2 ENG THROTTLE.