Fuel System of Conventional EFI-diesel


In the conventional EFI-diesel, control of injection timing and volume is performed electronically. The device that generates the fuel pressure is the same pump used in an ordinary diesel engine.

The fuel that is drawn up by the feed pump travels from the fuel tank through the fuel filter, and is introduced into the pump where it becomes pressurized and then pumped by the plunger inside of the injection pump. This process is the same as in an ordinary diesel pump. The fuel in the pump chamber becomes pressurized by the feed pump so that it is between 1.5 and 2.0 MPa. Furthermore, in accordance with the signals from the ECU, the SPV controls the injection volume (injection duration) and the TCV controls the fuel injection timing (injection starting timing).

Type of Pump

A conventional EFI-diesel uses one of the two types of

distributor pump: an axial plunger type pump, and a radial

plunger type pump with a higher injection pressure.

Internal construction of axial plunger type pump

Internal construction radial plunger type pump

Injection Pressure for Each Type of Pump

Axial Plunger Type Pump

(used on 5L-E 1KZ-TE, etc.) Approx. 80 MPa maximum

Radial Plunger Type Pump

(used on direct-injection engines

such as 1HD-FTE, 15B-FTE, etc.) Approx. 130 MPa maximum

Construction of Pump Portion of Axial Plunger Type Pump

The pump consists of the following:

Roller ring


Cam plate


Construction of Pump Portion of Radial Plunger Type Pump

The pump consists of the following:

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