Development of an experimental test bench for an electronically control fuel injection system

Abstract

Electronic fuel injection (EFI) system is a fuel delivery system that is controlled electronically with an electronic control unit (ECU) used in most modern vehicle’s engine. As the fuel injection runs on a vehicle engine, it is difficult to observe the overall behavior of the fuel injection system. A test bench for a 4-cylinder engine is generally developed to run the ECU without the real engine. The development of the test bench described in this paper includes the fabrication of the mechanical model of the test bench, the use of a signal generator for the input signals representing the various signals of an engine and the development of a computer control algorithm for the four-cylinder engine to provide optimum power and fuel efficiency for the engine. The input signal generation of the crankshaft signal and throttle position signal that are similar to the real signal provided by an engine is also discussed. The development of a cost-effective ECU that calculates the suitable amount of fuel to be delivered at correct timings and sequence is also explained. The important part of this paper is the control of the amount of time needed for the injectors to remain open to give the accurate amount fuel injected as well as to control the injection timing of a 4-cylinder engine sequence. The test bench can also be used for several experiments that require the measurement of fuel injected such as fuel injector performance test.