Virtual Instrumentation for Real - Time Measurement of Fuel Consumption in EFI Gasoline Engine

Abstract - At present, modern vehicles are embedded with Electronic Fuel Injection (EFI) system to dispense fuel into the engine for better fuel economy and reduced emission. An EFI engine uses electromagnetic injectors allows fuel at high pressure to enter the engineʹs combustion chamber. The timing of opening and closing of these injectors is controlled by an on - board microprocessor based Engine Control Unit (ECU), which uses a multitude of sensors on the engine to determine the precise metering of fuel. The only path fuel can take to leave the tank is through the injectors. By monitoring the signals from the ECU to these injectors, it is possible to calculate the exact amount of fuel being injected, and thus the rate of consumption. The aim of the present work is to develop a fuel injection test system that would be suitable for real - time measurement of fuel consumption in Electronic Fuel Injection (EFI) gasoline engine. Graphical dynamic system simulation software is emerging more popular in automation sector for measurement and testing applications. In an effort to develop real - time fuel injection test bench, graphical dynamic simulation software is used to simulate the functions of four stroke gasoline engine. This paper presents the design, implementation and the test results of an online system for instantaneous measurement and display of fuel consumption in a vehicle. For developing fuel injection programme, a virtual Instrumentation (VI) based software Labview version 8.5 and for fuel injection, a hardware named compact Field Point (cFP) the products of National Instruments (NI) were used. Labview software was used for programme development, data analysis, documentation of the results and Measurement and Automation Explorer (MAE) version 4.7software was used for hardware functioning. The test results show that linear approximation of injector flow response deserving to use an empirical formula on the calibrated fuel map. When operated the test system display real - time fuel injection quantity at corresponding pulse widths.