What was found
ON A 1.5 HR FLIGHT, THE RT MAIN TANK SHOWED A 600 LBS LESS DIFFERENCE THAN THE LT MAIN TANK. THE FUEL USED SHOWED EVEN AND THE FUEL FLOW WAS THE SAME FOR EACH ENGINE. ACFT GROUNDED. PERFORMED FQIS BITE REF FIM 28-41, TASK 801, NO FAULTS FOUND, FQIS CHECKS GOOD. CHECKED FUEL QTY TO FUEL STICKS IAW ALTERNATE FUELING PROCEDURES MANUAL, QTY IS CORRECT. PERFORMED CENTER TANK BOOST PUMP AUTO SHUTOFF FUNCTIONAL TEST REF AMM 28-22-00. OPS CHECK GOOD. DUE TO FUEL IMBALANCE BEING LESS THAN 1000 LBS, FUEL IMBALANCE CONDITIONAL INSPECTION IS NOT REQUIRED.