Swift L4-1298cc 1.3L SOHC MFI (1997)
Fuel Pressure Regulator: Description and Operation
The fuel pressure regulator is diaphragm-operated relief valve consisting of diaphragm, spring and valve. It keeps the fuel pressure applied to the injector
1.8kg/cm2 (180 kPa, 25.6 psi) higher than that in the intake manifold at all times. The pressure applied to the chamber "A" of fuel pressure regulator is
intake manifold pressure and that to the chamber "B" is fuel pressure. When the fuel pressure rises more than 1.8 kg/cm2 (180 kPa, 25.6 psi) higher than
the intake manifold pressure, the fuel pushes the valve in the regulator open and excess fuel returns to the fuel tank via the return line.