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| Illustration 1 | g00290848 |
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Typical example of a 3508B engine Fuel system electronic control circuit | |
The electronically controlled mechanically actuated unit injector fuel system provides total electronic control of injection timing. The injection timing is varied in order to optimize the engine's performance. This is a result of engine operating conditions.
The engine speed is controlled by adjusting the duration of injection. The timing reference ring is part of the rear gear group. The engine speed/timing sensor monitors the timing ring in order to provide information to the electronic control module (ECM). This information is for detection of crankshaft position and for engine speed. Other information and this data allows the ECM to correctly send a signal to the injector solenoids. The fuel injector's solenoid is energized in order to begin fuel injection. The fuel injector's solenoid is de-energized in order to end fuel injection.