What was found
NR 2 FUEL TEMP FLUCTUATES RAPIDLY BETWEEN +50 DEG C ALND +99 DEG C. C/W ABNORMAL CHECKLIST BY TURNING NR 2 FUEL BOOST PUMP ON. TEMP BEGAN TO STABILIZE BETWEEN +45 DEG AND +50 DEG WITH OCCASIONAL SPIKES ABOVE +71 DEG. ALL OTHER ENGINE INDICATIONS NORMAL. MAINTENANCE INSPECTED NR 2 FUEL TEMP CANNON PLUG. FOUND EXCESSIVE CARBON BUILD-UP IN FUEL TEMP SENSOR. CLEANED PLUG AND SENSOR CONTACTS. APPLIED CONTACT ENHANCER. GROUND RAN ENGINE. OPS CHECK GOOD. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.