What was found
SEA FLIGHT NR 2044, UPON BRINGING NR 2 ENGINE OUT OF FEATHER AFTER START, PILOTS AND FA DETECTED A BURNING ODOR. ODOR DISIPATED AFTER 5 MINUTES. FOLLOWING THAT WE WERE UNABLE TO CONTROL THE CABIN TEMPERATURE IN AUTO OR MANUAL MODE. ATTEMPTED LATCHED TRIM/PACK VALVES CHECKLIST WITH NO SUCCESS. MAINTENANCE REPLACED TEMPERTURE TRIM VALVE IAW -8 MMM 21-60-11, PAGE 401-405. ALSO REPLACED AIR CYCLE MACHINE IAW -8 AMM 21-50-11, PAGES 41-404. FUNCTIONAL CHECK OF THE TEMP CONTROL SYSTEM GOOD. AIRCRAFT RETURNED TO SERVICE.