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Home >> Audi >> 2012 >> Q7 3.0 TDI >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 7 (Fuel Supply System - Engine Code(S): Bar, BHK, BHL, CJWB, CJWC, CJWE, CTWA, CTWB) >> 20 Fuel Supply >> Description And Operation >> Function Of The Suction Jet Pumps

Function Of The Suction Jet Pumps

WARNING: This page is about a different variant/trim than selected.

Fuel tank is divided into a left and a right chamber. To transport fuel volume from left to right fuel tank chamber to fuel delivery unit baffle housing -4-, two suction jet pumps -1 and 6- are used.

Fig 1: Identifying Suction Jet Pumps Overview
GWWA20-10151Courtesy of AUDI OF AMERICA, LLC
  1. Front Suction Jet Pump
  2. Distribution Piece
    • For suction jet pipe
  3. Fuel Delivery Lines
    • From the suction jet pumps to the fuel delivery unit
    • Clipped to the fuel delivery unit
  4. Fuel Delivery Unit
    • With Transfer Fuel Pump -G6-
  5. Suction Jet Pipe
    • From fuel pump to suction jet pump
    • To disconnect, press release button on connection piece
  6. Rear 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 of Faulty Suction Jet Pump

CAUTION:

Tow-in due to faulty suction jet pump.

  • If suction jet pump is faulty, vehicle can stop running when tank is partially filled due to lack of fuel.

If vehicle stops with partially filled tank due to lack of fuel, proceed as follows:

-- Check fuel pump. Refer to FUEL PUMP ELECTRICAL, CHECKING .

If the fuel pump is OK, but no fuel is supplied:

-- Fill fuel tank with approximately 5 liters of fuel.

-- Start the engine.

If the engine starts now:

-- Replace suction jet pumps. Refer to SUCTION JET PUMPS .