whats the best pressure?
 

i have a walbro 255 fuel pump on my car. i have the fuel pressure regulator on it but i dont know wat is the best pressure for it. the car has no modes on it soo wat would be the recommended pressure for a stock rotor?

I'm going to take a shot at this for you. At idle, the fuel pressure should be about 28.4 psi. When the FPR is vented to the atmosphere, the fuel pressure should be between 34.1 and 34.9 psi. With engine off, ignition key to the on position, and yellow connector jumped, the fuel pressure should be between 64.0 and 85.3 psi. I think the Walboro runs at 40 psi.