As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER DEPARTURE FROM KMIA, NR 1 ENGINE RPM BEGAN TO INCREASE AND DECREASE DURING CLIMB OUT. AIRCRAFT DIVERTED BACK TO KMIA AND LANDED WITHOUT FURTHER INCIDENT. MAITNENANCE INSPECTED NR 1 ENGINE INLET AND EXHAUST IAW CHAPTER 71-00. NO DAMAGE FOUND, INSPECTED FCU AND FOUND WATER IN MOISTURE TRAP. MAINTENANCE CLEANED AND LUBE BELOW IAW MM CHAPTER 73-21-01. PERFORMED RUN UP IAW MM CHAPTER 71-00, OPS CHECK GOOD. AIRCRAFT RETURNED BACK SERVICE. (M)