L-Series Sedan (3 Door) 2WD F4-1781cc 1.8L SOHC (SPFI) (1986)
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Fuel Pressure Regulator: Description and Operation
Throttle Chamber
PURPOSE
Maintains fuel pressure at 21 psi (147 kpa) above manifold pressure.
LOCATION
On throttle chamber.
OPERATION
Fuel flows from the pump, through the lines, to the throttle chamber and injector, to the pressure regulator. Fuel pressure acting on the diaphragm
opens the return line orfice to the fuel tank. As manifold vacuums lowers (during accel), the spring in the diaphragm closes the passage, increasing
fuel pressure.
As manifold vacuum increases, the spring tension is overcome and the orfice is opened, allowing more fuel to return to the tank, lowering fuel
pressure.
