So on this one occasion you hit it with starter fluid and that means it's definitely fuel? How's the crank positioning sensor? No clue? Replaced with a Bosch 2 months ago? No chance it could have just been ready to start as in the other cases of no start?

I'm not saying "no way" it's fuel.. but you are having the classic Crank positioning sensor issues... click the red text in my signature "CPS"..