What was found
CLIMBING THROUGH 10,000 FT FLIGHT ATTENDANTS NOTIFIED COCKPIT OF RETURN OF FUEL FUMES, SMELL INCREASING THROUGHOUT ENTIRE CABIN. PAXS COMPLAINING OF INCREASED SMELL. RAN QRH 26.1 ACFT SMOKE FUMES WITH NO HELP. RETURN, NO EMER DECLARED. R & R APU FUEL CONTROL UNIT. OPERATIONS CHECKED GOOD IAW MM 49-30-01. COMPLIED WITH CABIN ODOR & SMOKE. TROUBLESHOOTING, COMPLIED WITH PACK BURNOUT, NO DEFECTS NOTED.