Functional testing of cut=out esp. on vehicular fuel-injected IC engine

摘要

The excitation current (i1) of the electromagnetic cut-out device and the operating current (i2) of the fuel metering device are respectively suppressed and reduced at the time (t1) of application of the cut-out command (1).The fuel metering current continues to flow at a reduced level (iL) corresp. to idling speed for a duration (t2 minus t1) corresp. e.g. to one revolution of the camshaft before being cut-off. In the meantime an event, such as injector needle movement or continuing combustion, which occurs only during running-on can be detected for the prodn. of a fault signal for the cutout device.