psi at high pressure fuelpump

[PaulinFL]

Suzuki df 60 1999 What should my fuel pressure be between HP fuel filter and Regulator?
Im checking to make sure my fuel pressure is correct on the HP fuel pump side. I hooked up a gauge between the HP filter and the rail and got 37psi. I cant find what the fuel pressure should be before the fuel pressure regulator. On the test for the fuel pressure regulator it says between 34-38psi. Shouldn't the pressure be higher before the regulator? If not then why have a pressure regulator. I'm going to test pressure at top of rail as soon as I can rig it up.

[redlowrey]

Fuel is supplied to the vst via the low pressure fuel pump, inside the vst fuel will fill to a level which is controlled by a needle and seat. Fuel is drawn into the suction side of the high pressure pump then pumped out of the vst through the high pressure fuel filter into the fuel rail, when the pressure exceeds about 38 psi the excess fuel is dumped via the pressure regulator in the vst. Remember the earth is duty cycled from the ecu, the only time it will have a full earth is when you fist turn the key on for thee seconds, and when you crank.

[PaulinFL]

ok i understand better now thanks. I checked the fuel pressure at the top of the rail and got 37-38 psi there as well and it stayed at that psi while running.