This system applies to diesel engines only.
This system is designed to control the formation of HC emissions. It controls the amount of recirculating fuel in the fuel injection pump in order to control the injection timing.
The injection timing advance system is composed of an injection timing control solenoid valve, a potentiometer, and EGR control unit and a revolution sensor. This system is also called a Partial Load Advancer (PLA). The system operates along much the same lines as the EGR system and shares many of the same components.