Description & Operation
The diesel electronic EGR system is controlled by the electronic control assembly which is mounted in the luggage compartment.
The system consists of a temperature sensor mounted on the cylinder head, a microswitch mounted on the injection pump, a speed sensor mounted on the engine block, a vacuum regulator mounted on the injection pump, a solenoid and an altitude switch mounted on the right side of the dash panel, an EGR valve and a vent valve.
With the ignition switch in the "START" or "RUN" position, power flows to the EGR solenoid. When the engine coolant temperature reaches 172°F (78°C) the temperature switch closes. With the engine at idle, the EGR microswitch is closed providing a ground for the EGR solenoid and the EGR valve is opened.
When the throttle is depressed, the EGR microswitch opens and the EGR valve closes. The speed sensor senses engine speed and sends this information to the electronic control assembly. With the engine speed between 1000 RPM and 2800 RPM, the electronic control assembly provides a ground for the EGR solenoid and the EGR valve is opened.