DIESEL PRESSURE PUMP AND CONTROL

Description 1060E

1.3 Multijet

Pressure pump

Type

It is the radial jet type with three radial pistons (total capacity 0.567 cc) and is operated by the camshaft through an oldham joint and does not have timing positions.

Structure

Each pumping unit consists of:

• a piston (5) operated by a cam (2) in one piece with the pump shaft (6);
• a plate-type intake valve (3);
• a ball delivery valve (4).

Because the pressure pump must be fed at a pressure of at least 0.7 bar, the fuel system is equipped with an auxiliary fuel pump submerged in the tank.

The maximum delivery pressure reaches 1400 bar.

The pressure pump is lubricated and cooled by the fuel via special channels.

1. Pressure pump

2. (Oldham) joint connected to camshaft

Pressure regulator

This is fitted on the rail and controlled by the injection control unit. It adjusts fuel feed pressure to the injectors.

The pressure regulator consists mainly of the following components:

• a spherical shutter (1);
• a valve (3) controlling pin (2);
• a preloading spring (4);
• a coil (5).

1. Spherical plunger

2. Pin

3. Valve

4. Preload spring

5. Coil

6. Case

7. Anchor

8. Filter