What was found
ON SECOND TAKEOFF DURING CLIMB, MAN. PRESS. DECAYED TO 27 INCHES HG. CLIMB CONTINUED AND POWER SLOWLY CAME BACK - NEXT TAKEOFF WAS NORMAL. REPLACED TURBO CONTROLLER AND ALL HOSES TO AND FROM WASTEGATE, ALSO, CONTROLLER DRAIN HOSE. A/C RAN TO TEST, APPEARED NORMAL. MADE TWO TAKEOFFS, FULL POWER, NO DEFECTS NOTED - THIS IS THE THIRD CONTROLLER THIS ENG HAS HAD. SUBMITTER STATED NOT SURE WHAT CAUSED THE PROBLEM OR IF IT IS CURED.