Sooooo, I've been chasing a fuel smell in my Shooting Brake project. It was so faint that I wasn't entirely sure that it was fuel (My family thought I was crazy-which I am). I've changed most of the fuel system, new tank, new fuel pump, etc etc. All of the hoses were replaced as well. Well, because I'd made so many changes it was hard to know what was wrong.

I read in Kirby Palm's Book about several sources for fuel smells. Turns out, one source that he offered, which I never would have believed, is that once you disconnect the metal hard lines connections the fittings lose their seal. In each bottom front corner of the trunk is a 90 degree brass fitting that have metal lines with compression fittings to seal the line. I'd removed these and then reinstalled without thinking it would be problematic. I think it was. My fix was to remove the fittings entirely and replaced with a straight through line (I also used non permeable marine fuel hose but I'm pretty sure the previous new hose was fine-I got paranoid and wanted to cover all bases). It appears that fuel smell is gone.

Most people are unlikely to have occasion to remove these lines but if you've tried all else then this might be something to try.

I'd also add that I solved a fuel smell problem on a previous car (86 Alfa Spider) by replacing the apparently leak free (original) rubber lines at the tank. There was absolutely no wetness on these lines but they were clearly emitting fumes (smell gone with new lines). What was also weird about the problem on the Alfa was that this was convertible car and was not at all air-tight, and the lines in question were under the car-not exposed directly to interior. This convinced me that fuel smells are absolutely unpredictable and exist contrary to any normal notion of leak discovery.