wsm M6060, Workshop Manual

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ENGINE M6060, M7060, WSM
1-M14
[3] RAIL
The rail (2) stores fuel at the high pressure applied
by the supply pump and supplies the shared pressure to
the injectors of each cylinder. The rail incorporates
control parts-a rail pressure sensor (3) and a pressure
limiter (1).
The pressure of the fuel in the rail is detected by the
rail pressure sensor, and optimal feedback control is
provided for the engine RPM and load. This greatly
improves the ability to raise the pressure at low RPMs
and enables high-pressure injection from low speed
ranges.
Pressure Limiter
The pressure limiter operates when the pressure
inside the rail becomes excessively high (valve opens),
and then once the pressure drops to a certain pressure,
it acts to keep the pressure (valve closes).
Fuel discharged by the pressure limiter returns to the
fuel tank.
Rail Pressure Sensor
The rail pressure sensor is mounted on the rail,
detects the pressure inside the rail and sends a signal to
the engine ECU.
This sensor is a semiconductor type of pressure
sensor, which uses the piezo resistance effect, in which
increasing the pressure on its silicon element changes
its electrical resistance. Please note that the rail
pressure sensor is not treated as a part, so replacement
requires replacing the rail assembly.
9Y1210828ENM0023US0
Valve opening pressure
Reference
value
Approx.
220 MPa
(2240 kgf/cm
2
, 31900 psi)
Valve closing pressure
Approx.
50 MPa
(510 kgf/cm
2
, 7300 psi)
(1) Pressure Limiter
(2) Rail
(3) Rail Pressure Sensor
(4) Valve (Open)
(5) Valve (Close)
(6) Rail Pressure
(7) Output Voltage
(8) Rail Pressure A: Return
B: Abnormally High Pressure
C: Rail Pressure
Characteristics
KiSC issued 08, 2013 A