Suction Jet Pump, Removing And Installing

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2020 Audi S4, 2019 Audi S4, 2019 Audi A4 allroad, 2019 Audi A4, and 2018 Audi S4. However, it is still accessible from the selected car via links, so may be relevant.

For AWD vehicles, the fuel tank 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 -1- of the fuel delivery unit -2-, a suction jet pump -3- is utilized.

Courtesy of AUDI OF AMERICA, LLC

Suction Jet Pump Function

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 from Faulty Suction Jet Pump

CAUTION:

Tow-in due to faulty suction jet pump.

If the suction jet pump is defective, the vehicle can stop running due to lack of fuel even if the fuel tank is up to ¹ /₄ filled.

If the suction jet pump does not function, up to 15 liters (4 gallons) of fuel (up to approximately ¹ /₄ ) remains in left chamber of fuel tank which cannot be extracted by the fuel delivery unit.

If the vehicle stops running due to lack of fuel even if the fuel tank is up to ¹ /₄ full check if the Transfer Fuel Pump -G6- is OK. Refer to Transfer Fuel Pump -G6-, CHECKING .

If The Fuel Pump Is Ok, But The Suction Jet Pump Does Not Function:

-- Fill approximately 5 liters (5 quarts) of fuel.

-- Start the engine.

If The Engine Now Starts:

-- Replace the fuel tank. Refer to FUEL TANK, REMOVING AND INSTALLING . The fuel tank is not available separately.