| 摘要 |
<p>A method of operating a compression ignition engine under cut-off conditions, such as release of the accelerator pedal. The method performs a control procedure that comprises the steps of: regulating the pressure within the fuel rail (170, fig.1) to a predetermined value (Pref); setting a desired value (Qdes) of a fuel quantity to be injected into the cylinÂder (125, fig.1 ); determining an energizing time (ET0) based on the desired fuel quantity value ((Qdes) and the fuel rail pressure value (Pref); and performing an empirical test that energises the fuel injector (160, fig.1) for the determined time (ET0) to perform a fuel injection during an engine cycle; measuring the pressure within the engine cylinder during the engine cycle in which the fuel injection occurs; and using the measured pressure to calculate a value (FCcal) of a parameter indicative of the fuel combustion within the engine cylinder . The measured value of this parameter can be regarded as an index of the performance of the fuel injector.</p> |
