On the 502 MPI it is plumbed to the seawater mounted mechanical pump with 3/8 line and It may even be 5/16 once it is pressurized. Remember that a mechanical pump does a much better job sucking than an electric because it is a diaphragm as opposed to a vane style pump.

Ok, so I bought a bravo res tank tonight, and hooked it up, and its still doing the same exact thing. Im begging to think maybe it doesnt have the exact 46 psi of fuel pressure that it needs. I dont have a guage on it, so I dont know the exact pressure. But I cant believe that its acting like its the "guardian mode" What I heard today was that you shouldnt be able to rev the motor in nutural over 3000 rpm, but I have no problem reving in nutural over 3000, but once in gear I cant get past 3000, its like the wires are hooked up wrong or something...

Did you do the diagnosis on the right side page? It will check all the discrete warning sensors.

heres what i did, remove vst and mech pump. get electric low pressure pump(i use mallory) and put it as close and low to your gas tank as you can. get a cool fuel system and your good. run the out line from the fuel rail back to the gas tank.
will not get guardian mode from sensor not being hook up...