I just wanted to share some insights and info about my 91 LS400. I had the hardest time tracking down a gas smell I was getting only once in a while. I would smell gas in the A/C after the car had warmed up, and only after making a few stops. I would come back to the car and it would reek of gas. Looking around under the hood I could never see a leak. Until one day after stopping I immediately opened the hood and really took my time looking around. After a few minutes there it was, not the fuel pressure regulator but on the other rail my "Fuel Pressure Damper". Out of the top it was spurting gas just under a small screw. The weird part is that when the car was running no leaks. From what I could gather when the car was running there was enough pressure in the rail to seal the leak, but as pressure bleeds off (up to 2-5 minutes after shutting off) it would leak. I replaced my Damper and haven't smelled gas since.
I also remember hearing of the LS400 having issues with engine fires while the car was stopped. Guess I know how that was happening.
Hope this helps someone.
