What was found
APU AUTO SHUTDOWN AFTER RUNNING FOR ABOUT 2-3 MINUTES. PERFORMED E/A CHECKLIST & OBSERVED STARTER LIMITS. NO APU FIRE WAS INDICATED. ATTEMPTED 2ND START & APU AUTOSHUT DOWN AGAIN AFTER RUNNING FOR 2-3 MINUTES. NO CURRENT FAULTS IN CDS. OPS TEST OF APU IAW AMM TASK 49-00-00-710-801. RAN APU FOR APPROX 1 HR. APU DID NOT AUTO-SHUTDOWN. C/W GVI OF APU, NO LEAKS NOTED. APU OPS CHECKED GOOD. RETURNED TO SERVICE. COULD NOT DUPLICATE.