What was found
(CAN) DURING A 200 HOUR INSPECTION A PIECE OF RUBBER WAS FOUND IN FUEL FILTER UPSTREAM FROM THE ENGINE DRIVEN FUEL PUMP, FURTHER INSPECTION FOUND A FOREIGN OBJECT SUBSEQUENTLY SAME MATERIAL, RUBBER, WAS FOUND PARTIALLY BLOCKING INSIDE OF FUEL SUPPLY LINE. LINE RETURNED TO ACFT MFG. UPON INSPECTION OF FUEL LINE BLOCKAGE WAS FOUND TO BE A PIECE OF TEFLON LINED RUBBER THAT WAS DISPLACED FROM INSIDE OF HOSE DURING MFG, LIKELY DURING INSTALLATION OF ALUMINUM HOSE-ENDS, AS 1 SIDE OF THE RUBBER HAD A STRAIT CUT AT ONE END.