Fuel Pump: Description and Operation

Suction Jet Pump, Function

NOTE: Arrow - points in direction of travel.







1. Left suction jet pump
- The fuel tank in a vehicle with all-wheel drive is divided into a left and right chamber.
- To move the volume of fuel from the left fuel tank chamber to the right baffle housing - 8 - of the fuel delivery unit, a suction jet pump - 1 - is utilized.
- A second suction jet pump - 7 - is positioned in the right fuel tank chamber and improves the fuel supply to the baffle housing of the fuel delivery unit.
- Function of the suction jet pumps is based on a simple physical principle: A suction jet from the fuel return line - 3 - is compressed by a nozzle in the suction jet pumps - 1 - and - 7 - and is thereby accelerated. This acceleration causes the surrounding fuel to be drawn in and be forced to the baffle housing of the fuel delivery unit. The right suction jet pump - 7 - delivers directly into the baffle housing, the left suction jet pump - 1 - via a separate line - 4 -
- The fuel from the return line is distributed to both suction jet pumps via the Y-fitting - 2 -. The distribution piece - 6 - limits the pressure in the lines to the suction jet pumps to approx. 1 bar. Excess fuel is guided into the baffle housing via a direct line.