D21 Hardbody 2WD L4-2389cc 2.4L SOHC MFI (KA24E) (1990)
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Fuel Pressure Regulator: Description and Operation
Fuel Pressure Regulator
PURPOSE
Controls fuel pressure.
LOCATION
On the fuel rail.
OPERATION
The fuel pressure regulator maintains the fuel pressure at 43.4 psi (299.1 kPa/3.05 kg-cm2) at idle. It has a variable diameter orifice that restricts
the fuel outlet flow. It is controlled by manifold vacuum acting upon the diaphragm.
When manifold vacuum is high, the diaphragm is pulls the orifice toward the open position allowing more fuel to be returned to the fuel tank,
lowering fuel pressure. When manifold vacuum is low, the diaphragm is pushed toward the closed position by the internal spring. This allows less
fuel to be returned to the fuel tank, thereby increasing fuel pressure.
