摘要 |
The invention concerns a method of determining the velocity of a pintle assembly in a solenoid fuel injector during a closing stroke of the pintle assembly, wherein a braking step is performed during the closing stroke, which comprises operating an injector driver with current regulator to establish a braking current in the solenoid coil. The velocity of the pintle assembly is derived from the duty-cycle of the current regulator during the braking step. A method of operating a solenoid fuel injector, in particular for gaseous fuel, using the so-determined pintle velocity is also disclosed. |