Fuel Control
The fuel control system delivers fuel to the engine. Fuel from the in-tank fuel pump flows to the fuel rail, injectors and pressure regulator. The pressure regulator maintains fuel system pressure at 31-39 psi (2.l-2.7 kg/cm2 ). Excess fuel is returned to the tank by a fuel return line.
The fuel pump is energized through the fuel pump relay that is located on the right inner fender panel in the engine compartment. Battery voltage is provided through the ignition switch and is energized when the ECU completes the ground path.
The fuel injectors are electrically operated solenoid valves. The ECU determines injector pulse width ("on/off") time based upon engine operating conditions and delivers the proper pulse width to maintain an air/fuel ratio of 14.7:l.
The ECU varies the amount of voltage applied to the injectors to compensate for battery voltage changes. Battery voltage information is provided to the ECU through the wiring harness. No sensor or switch is required.