What was found
THE APU WAS RUNNING NORMAL WHEN IT SHUTDOWN BY ITSELF FOR NO REASON. TRIED TO RESTART THE APU BUT IT WOULD NOT GO PAST 23 PERCENT. DID A COMPLETE RESET OF THE AIRPLANE AND SYSTEMS. TRIED TO START THE APU AGAIN AND WOULD NOT PASS 23 PERCENT. THE APU WILL NOT START. 09-28-07 CHECKED THE INTAKE AND EXHAUST CONNECTORS ON APU, AND APU OIL LEVEL. ALL FOUND NORMAL. PERFORMED HONEYWELL ECU BIT DISPLAY FOUND NO FAULTS. MADE 2 STARTS WITH ELECTRIC AND PNEUMATIC LOADS. SYSTEM RUNS NORMAL- IAW WITH HONEYWELL M/M 49-20-00.