CAC Gasoline Engine Maintenance And Servicing Manual
87
3.2 fuel filter
Fuel filter (see drawing 143) is connected between fuel pump and
the fuel intake port of the throttle valve body. It comprises an aluminum
case and a bracket with a stainless steel in it. for the high sensitivity of
fuel injector and the the existence of external impurities being in the fuel
system, it is necessary to use the high-efficiency paper filter core.
4.1water temperature sensor“WTS05”
during cold starting and engine warming, ECU enrich the mixture according to the signal (see figure 6)
from the sensor. When engine is warmed enough for fan to reach the operation range, the enrichment is zero.
4.2 speed, top dead center and
s
ynchro pickup“CVM01”see figure. 144
Sensor is mounted on the cylinder block by a mounting bracket. When it detects the impulses produced by
the teeth (60—2) in the flywheel (see figure. 143), engine speed may be calculated accurately by the signal
impulses produced by the 58 teeth which are arranged equally with a interval of 6°.
The RPM sensor position in the flywheel (signal wheel) is on the surface of the twentieth tooth before the
top dead center of the cylinder 1, 4, the angle between it and the top dead center of cylinder 2, 3 is 80°, on the
opposite of the fiftieth teeth (tooth counting begins from the tooth-missed area), except for deciding cylinder
1,4 and cylinder 2,3 TDC, the sensor signal (see figure. 144) is also used in the microprocessor:
—— Control ignition ( ignition advance and ignition delay)
—— generate signal for the RPM counter
—— detect two missed teeth to confirm the synchronous position every engine revolution
Without the signal or the corresponding synchronous signal (60—2 signals/revolution),ECU cannot be
operated.
Fig. 143 fuel filter
sensor characteristic
winding
positive signal
negative signal
grounding singal
Fig. 144 tacho sensor
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