Speed Sensor
Located just below base plate of distributor, the speed sensor consists of 2 components. First component is a set of reed switches mounted within a plastic housing. See Fig. 4 . The second component is a plastic rotor with 2 magnets (called flags), attached to and rotating with distributor shaft. Each flag furnishes signal for each injection group. As flags rotate past reed switches, the switches open and close and this information is sent to ECU. This type of signal is basically a tachometer signal for each group of injectors.