I have an LSA but not the PCM version; I have Marine Power. That being said, aside from the ECM and fuel pump(s), the engines are otherwise identical. The only metal line I know of in that size is the fuel rail that wraps around the intercooler cover. That would not be the ideal place to install a fuel pressure gauge. The fuel rail starts at the rear of the starboard side of the engine and most likely there would be a rubber hose running from your fuel pump(s) (it's my understanding that PCM opted for a two-stage fuel pump much like what is used in the automotive application) to the fuel rail. It would make the most sense to have it there so the pressure drop from fuel injectors operating wouldn't give a false reading. You could also check your fuel pressure with a fuel pressure gauge attached to the Schrader valve (you wouldn't want to leave it there permanently as I'm pretty sure it would ultimately snap off from metal fatigue which would be a very unfortunate event) on the starboard side of the fuel rail. Finally, I would have to ask him to be sure, but a friend of mine has the PCM and he has a digital panel that shows all the information while running. He had told me that he can access everything on the panel that he can access using Diacom on his laptop. I also use Diacom to monitor my engine from time to time (it's not practical to have my laptop with me while out riding) to check trouble codes and overall health of the engine. It literally shows everything you could possibly want to know. It costs around $700 and is worth every penny.
