E 350 V8-6.0L DSL Turbo VIN P (2004)
Fuel Pressure Regulator: Description and Operation
Standard Models (Non Bi-Fuel)
Gasoline Fuel System
FUEL PRESSURE REGULATOR
Fuel Pressure Regulator
The fuel pressure regulator (Figure 75) is attached to the fuel rail downstream of the fuel injectors. It regulates fuel pressure supplied to the fuel
injectors. The regulator is a diaphragm-operated relief valve. One side of the diaphragm senses fuel pressure and the other side is connected to the intake
manifold vacuum. Fuel pressure is established by a spring preload applied to the diaphragm. Balancing one side of the diaphragm with manifold vacuum
maintains a constant fuel pressure drop across the fuel injectors. Fuel pressure is high when engine vacuum is low. Excess fuel is bypassed through the
fuel pressure regulator and returned through the fuel return line to the fuel tank.
Natural Gas Fuel System
FUEL PRESSURE REGULATOR
Fuel Pressure Regulator
The fuel pressure regulator (Figure 82) used in the Natural Gas fuel system is a single-stage pressure reducing regulator which expands natural gas from
storage pressures of 1,379 to 20,685 kPa (200 to 3,000 psig) to engine fuel injector pressures of 724 to 862 kPa (105 to 125 psig).
