Your Vehicle: 2001 Ford Escort ZX2 L4-2.0L DOHC VIN 3
Vehicle » Powertrain Management » Fuel Delivery and Air Induction » Fuel Pressure Regulator » Description and Operation  
  Description and Operation  


Fuel Pressure Regulator

The fuel pressure regulator (Figure 70) 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.