What was found
AT CRUISE FLIGHT OF 23,000, THE NR 1 ENGINE FUEL PRESSURE CAUTION FLASHED ON AND OFF ABOUT 12 TIMES. DID NOT SELECT THE NR 1 AUXILIARY PUMP ON, DUE TO THE CAUTION FLASHING ON FOR LESS THAN 1-2 SECONDS EACH TIME. DIVERTED AND ACCOMPLISHED UNEVENTFUL LANDING. FOUND NR 1 ENGINE CHANNEL A AND CHANNEL B FAULT 911, LOW FUEL PRESSURE. REPLACED NR 1 ENGINE FUEL FEED LINE COUPLING. FOUND CLAMSHELL FELL OFF AND OTBD O-RING CUT 25 PERCENT. ACCELERATION CHECK IAW AMM 71-00-00-868-807. RETURNED TO SERVICE.