As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ENGINE START LEFT ENGINE WAS IDLING HIGHER THAN RIGHT ENGINE, ITEM WAS CREW DEFERRABLE. THE DEFERRAL REQUIRED MORE FUEL TO BE ADDED FOR FLIGHT. AIRCRAFT BACK TO BLOCKS, GROUNDED BY MAINTENANCE UNTIL DEFERRAL WAS COMPLETE AND FUEL WAS ADDED.