Legacy Sedan 2WD F4-2.2L SOHC (1990)
Fuel Pressure Regulator: Description and Operation
Fuel Pressure Regulator
PURPOSE
Maintains fuel pressure at 36.3 psi (250.1 kPa) above manifold pressure.
LOCATION
On the R.H. injector rail.
OPERATION
Fuel flows from the pump, through the lines, to the injectors and to the pressure regulator. Fuel pressure acting on the diaphragm opens the return
line orifice to the fuel tank. As manifold vacuums lowers (during acceleration), the spring in the diaphragm closes the passage, increasing fuel
pressure.
As manifold vacuum increases, the spring tension is overcome and the orifice is opened, allowing more fuel to return to the tank, lowering fuel
pressure.