Emission Controls for a 2.2L Diesel Engine

The adoption of stringent emission control requirements for diesel powered vehicles has generated the need for emission reducing engine controls. An exhaust gas recirculation system controlled by a true mass airflow sensor has been developed for a light duty truck equipped with a 2.2 liter, naturally aspirated, diesel engine to satisfy these requirements. An intake air throttle provides a method of reducing the intake mass airflow to the engine. The air/fuel ratio, which will simultaneously obtain the desired NO_x emission level and minimize any increase in particulates, is achieved by a combination of intake air throttling and introduction of exhaust gas recirculation. The control system reduces emission output in a simple, cost effective manner, without adversely affecting fuel economy or driveability.