Cold Start Device; High-Altitude Injection Control Device - Isuzu 3CH1-NGZG01 Introduction Manual

TNV_OperationManual_T4(under 19kW).book Page 56 Wednesday, June 17, 2015 11:23 AM
ENGINE OPERATION

COLD START DEVICE

WARNING
Sudden Movement Hazard!
• Engaging the transmission or PTO at an
elevated engine speed could result in
unexpected movement of the equipment.
• Failure to comply could result in death or
serious injury.
The cold start device on direct injection models
improves engine starting at lower temperatures.
• If the engine cooling system temperature is below
5 °C (41 °F), the cold start device automatically
advances the fuel injection timing and slightly
increases the fuel injection volume.
• The engine idle speed will be slightly elevated for
approximately the first 5 minutes of operation.
• When the cold start device is activated, you may
notice a slight increase in the amount of exhaust
smoke. This is normal.
• Never engage the transmission or PTO while the
cold start device is activated or unexpected
movement of the machine may result.
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HIGH-ALTITUDE INJECTION
CONTROL DEVICE
3CH1, 3CJ1
This series has a high-altitude injection control
device installed. It suppresses black smoke when
operating at high altitudes and at the same time
aims to control particulate matter.
The device consists of an output control solenoid
that is attached to the fuel injection pump and a
solenoid driver (with an atmospheric pressure
sensor) that is assembled on the implement side.
The output control solenoid actuates at engine
start. (It does not actuate during engine operation.)
At engine start, the starter operates and the engine
starts running. 4 seconds after the starter turns off,
the solenoid driver measures the atmospheric
pressure and determines whether to actuate the
solenoid. (The solenoid is energized during normal
operation, but it is turned off during the start of the
control device.) If at this time the atmospheric
pressure sensor determines that the altitude is
2624 ft (800 m) or more, the control device
operates. It reduces the fuel injection amount and
thus controls the occurrence of black smoke.
Because of this reduction in the injection amount,
the output decreases. At 5500 ft (1676 m), the
decrease in output (i.e. torque) is 20 % of the
maximum at low altitudes. Therefore, only apply
medium to low load when operating at high
altitudes.
The injection control device does not actuate during
engine operation. (Switch operation is not
performed.) Therefore, when the control device is
not yet operating and the machine is moved to a
high altitude during operation, or when the control
device is already operating and the machine is
moved to a low altitude, turn the key switch to OFF
(engine stop). This resets the control device. After
re-starting the engine, the necessity for injection
control is again determined.