Kubota M108S, Workshop Manual

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1-M8
M108S, WSM ENGINE
5. FUEL SYSTEM
[1] GENERAL
W1013924
The fuel system of Kubota common rail system diesel engine is shown in the diagram above.
Fuel from the tank flows in the passage as shown by the arrows, and is injected from the injector (1) via the supply
pump (3) and the rail (2). Overflow fuel returns to the tank through the fuel cooler (5).
The system includes filters and other concerns to protect it from entrance of air, water and dust.
While the key switch is at “ON” position, fuel is fed into the supply pump (3) by the electromagnetic fuel feed pump
(8) after passing through the water separator (9) and fuel filter (7) where any foreign matter is removed.
The fuel sent from the electromagnetic fuel feed pump (8) has the required discharge quantity adjusted by the SCV
(Suction Control Valve) (4) and enters of the supply pump (3). The fuel pumped by the supply pump (3) is sent by
pressure through the delivery valve to the rail (2).
The injector (1) injects the pressurized fuel in the rail into the engine combustion chamber at the optimal injection
timing, injection quantity, injection rate, and injection pattern, in accordance with signals from the engine ECU
(Electronic Control Unit).
(1) Injector
(2) Rail
(3) Supply Pump
(4) SCV (Suction Control Valve)
(5) Fuel Cooler
(6) Check Valve
(7) Fuel Filter
(8) Electromagnetic Fuel Feed
Pump
(9) Water Separator
(10) Fuel Tank
A : Injected Fuel Flow
B : Returned Fuel Flow
KiSC issued 06, 2007 A