I've been looking for the source of the fuel smell and have checked the engine, the fuel tank and the fuel line connections in the fuselage and have not been successful in finding a leak. The only place I've not checked is the tunnel under the Panel Base. Removed the map tray, carpet cover and the F-1230 Tunnel Cover. I found a yellowish film on the F-1259M Fuel ReturnLine from its connection to the union bulkhead fitting at the Firewall Shelf all the way to the bottom. There is also a yellowish stain on the tunnel floor. The stain has a slight smell of fuel. Perhaps, the smell would have been stronger if I removed the tunnel cover yesterday. Removed the bolt at the FT-60 Floscan that secures the cushion clamp and wire bundles, and cut several tire wraps so I'll have more space with my hand and tools. The AN818-4D fitting conected to the union bulkhead fitting was not tight and I can't remember if I applied thread sealant when I installed the fitting a long time ago. Instead of just tightening the fitting I decided to unscrew it completely, cleaned the threads and applied Loctite 567 thread sealant. Reconnected the fitting and turned the fuel pump on and did not see a leak. Inspected the fuel line connections at the Fuel Valve using a flexible inspection videoscope and did not see any sign of a leak at this area. Re-installed the bolt and cushion clamp to the Floscan. Replaced the tie wraps that I had cut. Will leave the Tunnel Cover off for now.
