Komatsu 170-3 Series, Руководство по ремонту, Страница: 141 / 454

170-3 SERIES
12-15
TESTING AND ADJUSTING
3. Measuring fuel pump outlet pressure
(with sensor)
1) Insert cable N7 in the connector of fuel pump
pressure sensor (3).
2) Start the engine and measure the power
source voltage of the fuel pump pressure
sensor.
★
Check that the power source voltage is
within the following range.
★
Sensor power source voltage (between
(A) and (B)): 4.75 – 5.25 V
3) Run the engine at each speed and measure
the signal voltage of the fuel pump pressure
sensor.
★
Check that the power source voltage is
within the following range.
★
Sensor power source voltage (between
(C) and (B)):
Engine
speed
(rpm)
Signal
voltage
(V)
Fuel pump outlet port
pressure (reference)
(MPa{kg/cm
2
})
600 1.78±0.21
0.83±0.14
{8.45±1.41}
700 1.94±0.21
0.93±0.1
{9.50±1.41}
800 2.10±0.21
1.03±0.14
{10.53±1.41}
900 2.26±0.21
1.14±0.14
{11.60±1.41}
1,000 2.42±0.21
1.25±0.14
{12.70±1.41}
1,100 2.59±0.21
1.34±0.14
{13.70±1.41}
1,200 2.76±0.21
1.46±0.14
{14.90±1.41}
VISUAL INSPECTION OF
RETURN FUEL
★
The fuel used for control of the timing rail in the
fuel circuit and the excessive fuel that is not used
injected in the fuel rail are returned from the
injector through the fuel cooler to the fuel tank.
★
If the engine does not revolve normally or fuel
consumption is abnormally high, inspect the
return fuel according to the following procedure.
1. Disconnect the fuel return hose before the fuel
tank.
★
Plug the hole of the fuel tank.
★
Keep the return hose open and receive the
fuel with an oil pan, etc.
2. Start the engine and check that the fuel flows out
of the fuel return hose smoothly.
★
Fuel spillage (Reference)
At low idling: 4 – 6 /min
At high idling: 10 – 12 /min
★
If the fuel spillage is extremely low, check the
return piping and fuel cooler for clogging.
➄
MEASURING FUEL CIRCUIT PRESSURE,
VISUAL INSPECTION OF RETURN FUEL
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