I had a tremendous pressure backing up in my 1986 non-turbo Z31 300ZX gas tank to the point that gas would sometimes gush out when you unscrewed the cap. I removed the canister and did my best to blow it out. That still didn’t work. I understand there is a way to bypass it by connecting some of the pressure tubes and maybe blocking some. There are 4 tubes on top and one large one on the bottom. Anybody know how to do this?