Subaru LEGACY 2002 Quick Reference Index page 188

Fuel Injection (Fuel System)
B: PRESSURE REGULATOR
The pressure regulator is installed at the injector end of the fuel supply line. It has a fuel chamber
and spring chamber separated by a diaphragm. Fuel chamber is connected to the fuel supply line
and the spring chamber is connected to the intake manifold. Fuel chamber also has a relief valve
connected to the fuel return line through which fuel returns to the fuel tank. When the intake man-
ifold vacuum increases, the diaphragm is pulled and the relief valve opens to decrease the fuel
supply line pressure (or fuel injection pressure). When the intake manifold vacuum decreases, the
diaphragm is pushed by the spring to increase the fuel supply line pressure. Thus, the difference
between the fuel injection pressure and the intake manifold vacuum is kept at a constant level of
299.1 kPa (3.05 kgf/cm
(2)
(1) Relief valve
(2) Diaphragm
FUEL LINE
2
, 43.4 psi) to precisely control the amount of injected fuel.
A
B
(1)
A: To intake manifold
B: Fuel IN
C: Fuel OUT
FU-8
C
S2H0623C