I run the stock 1998 Glanza engine in my Tercel with a FMIC. On warm days (20-30 celcius degrees), I can reach 13.5 psi without getting on the fuel cut, but on cold days (0-15 celcius degrees), FC comes in around 13 psi. I think what you experimented is normal. Can you make a test and reach the fuel cut to see at how much pressure it comes in?