13E
13E-7
CAUTION
• Be sure to connect the SCV (suction control valve) connector to the engine harness before starting the
engine. If the engine is started with the SCV (suction control valve) connector not connected, control of
the supply pump by the engine electronic control unit would not be possible and a fault would ensue.
• The supply pump pressurizes fuel and supplies it in a highly pressurized state.
• Fuel drawn from the fuel tank by the feed pump is not supplied directly to the plungers. It is supplied first to the
common rail pressure solenoid valve, which controls the amount of fuel reaching the plungers.
• If the fuel pressure exceeds a certain level, the regulating valve returns fuel to the inlet side of the feed pump. This
operation keeps the pressure of the fuel fed to SVC (suction control valve), constant.
• Rotation of the camshaft causes (via the ring cam) up-down movement of the plungers. Fuel in the plunger cham-
bers is thus highly pressurized.
(1) SCV (suction control valve)
• The SCV (suction control valve) receives fuel from the feed
pump and feeds fuel toward the plungers of the supply pump in
such a quantity that the fuel pressure corresponds to that re-
quired by the engine electronic control unit.
• When the SCV (suction control valve) is not operating, i.e., when
current is not flowing, fuel flows at its maximum rate. When cur-
rent flows, the piston in the common rail pressure solenoid valve
is pressed down such that fuel is not fed toward the plungers.
• The engine electronic control unit controls the ratio of current-off
time (duty ratio).
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