What was found
IAH - FLIGHT 2680, THE CREW REPORTED THAT AFTER STARTING THE APU ON THE GROUND, AND OPENING APU BLEED AIR, THERE WAS A STRONG ODOR OF JET FUEL IN THE CABIN. THE AIRCRAFT CONTINUED TO THE GATE WHERE MAINTENANCE OPERATIONALLY CHECKED THE APU WITH NO DEFECTS, OR ODORS NOTED AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.