Fuel Metering System
DescriptionThe fuel metering system is made up of the following parts:
^ The accelerator controls
^ The throttle body
^ The throttle position (TP) sensor
^ The idle air control (IAC) valve
^ The mass air flow (MAF) sensor
^ The fuel rail
^ The fuel injector
^ The fuel pressure regulator
^ The Powertrain Control Module (PCM)
^ The crankshaft position sensor
^ The camshaft position sensor
^ The idle air control valve (IAC)
^ The fuel pump
Basic System Operation
The fuel metering system starts with the fuel in the fuel tank. An electric fuel pump, located in the fuel tank with the gauge sending unit, pumps fuel to the fuel rail through an in-line fuel filter. The fuel pump is designed to provide fuel at a pressure above the pressure needed by the fuel injectors. A fuel pressure regulator in the fuel rail keeps fuel available to the fuel injectors at a constant pressure. Unused fuel is returned to the fuel tank by a separate pipe.