Suction Jet Pump, Vehicles With All Wheel Drive As of 11.04

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 -3- to the right baffle housing of the fuel delivery unit -2-, a suction jet pump -1- is utilized.

Function of suction jet pump
Function of the suction jet pump is based on a simple physical principle: A suction jet from the electrical fuel pump is compressed by a nozzle in the suction jet pump 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.

Malfunctions of faulty suction jet pump

CAUTION: If suction jet pump is faulty, the vehicle can stop running due to lack of fuel, though the fuel tank is up to 1/4 filled.


If suction jet pump does not function, up to 20 liters of fuel (up to approx. 1/4 tank) remain in left chamber of fuel tank, because it can not be extracted by the fuel delivery unit.

If vehicle stops running, although the fuel tank is approx. 1/4 filled, proceed as follows:
- Check fuel pump.

If fuel pump is OK, but no fuel is supplied:
- Fill fuel tank with approx. 5 liters of fuel.
- Start engine.

If engine starts now:
- Replace suction jet pump.