2jz wont rev at 2800!!

[RHD]

How do you have an external regulator without a return line??

It's possible an air lock would do it. We have had a 350z do the same thing. Car was completely stock, come to find out, the plastic fuel pump housing had a very small crack in it, so when it was low on gas, it would make a horrible noise (pump trying to pump fuel and air).

I hope that is the problem.

Yes its not the way i like to arrange the fuel system but its not my car, its quite simple the fuel rail is a billet one so one end is blocked off and the other end is just connected with a single hose to the pressure side of the regulator then the return from the reg goes back to the tank as usual. Many oem cars are actually configured in a similar way these days, it does have one small benefit of the fuel not continually circulating through the fuel rail and getting heated up leading to more vapor etc.