An Electronically Controlled System for Parametric Studies on Fuel Injection in an Automotive Gasoline Engine

An electronic system was developed for the control of the injection timing and injected fuel quantity for studies on a passenger car engine. This system can be used to produce maps of these parameters for implementation in an electronic control unit. The complete electronic hardware which included the cam position sensor, pulse shaping, pulse delay and sequencing features was developed and tested. The system could control the injection pulse width for the different cylinders independent of each other.

The developed system was used to conduct parametric studies. The results obtained were compared with that obtained from the base carbureted engine. There was a significant improvement in brake thermal efficiency and reduction in HC and CO emissions with the injection system. A retarded injection timing was needed at low loads. The volumetric efficiency of the injection system was much higher than the carbureted version. Since the system was tuned for lean mixtures the power output was lower.