| 摘要 |
Methods and apparatus are provided for testing a fuel pump in a fuel supply system on a IC fuel injected engine, the pump having a pumping element for supplying fuel injectors via a fuel rail. The method includes providing a pump element pumping event; disabling overlapping injectors during a test-period that includes the pumping event; measuring pressure in the rail at least two engine crank angles surrounding the pumping event during the test period; and determining a fuel delivery rate value for the pump based on the measured rail pressures. Methods and apparatus also are provided for determining quantitative leakage rate in the fuel supply system of a fuel injected IC engine, the fuel system including a fuel pump with one or more pumping elements supplying injectors via a fuel rail. The method includes establishing steady state engine operating conditions with fuel rail pressure at a predetermined value; disabling all overlapping injectors and all pumping events during a test period; measuring rail pressure at preselected first and second crank angles during the test period, the first crank angle being advanced relative to the second crank angle; and calculating the leakage rate based on a pressure drop determined from the measured rail pressure at the first crank angle and the measured rail pressure at the second crank angle.
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