Influence of Supply Voltage over Fuel Injector’s Deadtime

This study presents three methods for obtaining the latency of an indirect injection Electro-Injector as a function of the applied voltage. This parameter is relevant for the linearization of the injected mass in order to model fuel mass delivery on modern ECUs. For this purpose, the authors built a test bench, with the intent of running analysis on the results of tests of mass differential between injections, circulating current, and mechanical vibration. The authors gathered data over the iterative experiments and correlated the mass differential, vibration data and current measurements. The authors observed that with a reduction of supply voltage at the injector’s pins, a greater injector dead time made itself present displaying a need for a compensation of opening time in function of voltage since the injector’s needle takes a longer amount of time in partially open positions. Modern ECU manufacturers broadly use the data obtained by this type of iterative experiment to accurately model fuel mass-flow over different boundary conditions not limited only to supply voltage but also differential pressure and fuel temperatures.