User Manual

SENR9977 19
Systems Operation Section
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Illustrat
ion 19
Timing advance for timing mechanism (side view and top view)
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Illustration 20
Timing retard for timing m echan ism (side view and top view)
The timing advance or the timing retard of the fuel
injectionpumpisshowninthefollowingsteps:
1. The ECU sends a signal to the timing solenoid
valve.
2. The timing mechanism is triggered by the timing
solenoid valv
e.
3. The timing solenoid valve changes the pressure in
the timing mec
hanism.
4. The timing mechanism changes the position of
the cam ring.
5. The cam ring changes the position of the rollers.
6. The rollers change the position of the cam plate.
7. The cam plate c
hanges the timing of the fuel
delivery.
Control
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Illustration 21
Electronic control for the fuel system (typical example)
The ECU for the injection pump uses the command
from the ECM and the measured values from the
speed/timing sensor to actuate the fuel solenoid
valve.