I found what appears to be a second fuel filter on a line near the filler. It's smaller than the filter near the engine, and it's made of plastic. It's in that mess of tubes covered by the grey panel behind the passenger seat. It looks stock because it has those funky OEM hose clamps on it. Is this another fuel filter, or is it some kind of check valve? I could blow air through both ends of it, but it took a lot of pressure. It's on my '77 FJ40. I apologize for not taking any pics of it.