System Configuration of Supply Pump


1. Outline

The fuel that has been drawn up from the feed pump located inside the supply pump is pressurized to the required pressure. The plunger in the pump generates the required injection pressure. The pressure varies by engine speed and load conditions from 20 MPa at idle, to 135 MPa under high-load, high-speed operating conditions. (In the conventional EFI-diesel, the pressure is between 10 to 80 MPa.) The ECU commands the SCV (Suction Control Valve) to adjust the fuel pressure, regulating the volume of fuel that enters the supply pump. The ECU constantly detects the fuel pressure in the common-rail by means of the fuel pressure sensor, and effects feedback control.

2. Parts name

Appearance of the Supply Pump

1. Parts name

2. 2KD-FTV and 1ND-TV engine

Internal Construction of Supply Pump

1. Regulator valve

2. Feed pump

3. SCV (Suction Control Valve)

4. Check valve

5. Plunger

6. Inner cam

7. Delivery valve


Fuel Flow of the Supply Pump

The fuel in the supply pump flows in the following order:

Feed pump

SCV (Suction Control Valve)

Check valve


Delivery valve

There are two systems of fuel passages in the supply pump.

2KD-FTV Engine

For the fuel flow of the supply pump, which is used in the 2KD-FTV engine, plunger B draws the fuel in while plunger A pumps it out as illustrated on the left. Thus, plunger A and B send the fuel into the common-rail by drawing in and pumping out the fuel in turn.


Fuel Flow of Supply Pump

1ND-TV Engine

The supply pump used in 1ND-TV engine has three plungers as illustrated on the left, and sends the fuel into the common-rail by drawing in and pumping out the fuel in turn. This process is basically the same as that in the 2KD-FTV except that the 1ND-TV uses three plungers. The 1ND-TV engine also controls the fuel volume drawn into the plunger with the MPROP (Magnetic Proportional Valve), which has the same function as SCV (Suction Control Valve).

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