METHOD OF DIAGNOSING ENGINE FUEL FEED SYSTEM ELECTRICALLY DRIVEN FUEL PUMPS Russian patent published in 2013 - IPC F02M65/00 

FIELD: engines and pumps.

SUBSTANCE: proposed method consists in measuring engine crankshaft rpm drop at alternate cutoff of every cylinder by electronic ignition switch that terminates sparking in selected cylinder at preset time intervals. Note here that tester motor is connected to automobile to be tested while electromagnetic injector switch is used as said ignition cutoff switch. Engine crankshaft rpm is set to comply with appropriate maximum output of electrically driven fuel pump to be kept invariable by maintaining maximum duration of fuel injection. Sequential fuel feed by tester motor is controlled to adopt a constant value. Engine crankshaft rpm is measured by tester motor unless fuel is completely consumed. Fuel consumption notable decrease indicates insufficient output of fuel pump. To particularise pimp faults, transparent tube is placed in drain line for sensory control over fuel availability in drain tube. Total lack of fuel or discontinuous flow indicates wear-out of fuel pump. To particularise degree of pump wear, pump terminals are connected to controlled-voltage external power supply to sequentially set 12 V, 10 V and 8 V so that engine crankshaft rpm is controlled at said voltages and time of fuel supply by pump. Fuel consumption and engine crankshaft rpm vs pump supply voltage of 8 V, 10 V and 12 V is plotted to define pump wear from comparison from plotted relationship with reference one.

EFFECT: higher accuracy of diagnostics.

2 cl, 2 dwg