Open Fuel Injectors, Checking

WARNING: This page is about a different car, the 2016 Audi Q5, 2015 Audi Q5, and 2014 Audi Q5. However, it is still accessible from the selected car via links, so may be relevant.

Open injector means: the nozzle needle does not close all of the way and fuel leaks into the cylinder.

Special tools and workshop equipment required

Hand Vacuum Pump VAS6213

Fig 1: Hand Vacuum Pump VAS6213
Courtesy of AUDI OF AMERICA, LLC
Make an -adapter- for the return line.

Fig 2: Hand Vacuum Pump
Courtesy of AUDI OF AMERICA, LLC

Procedure

-- Use a Vehicle Diagnostic Tester to check the Diagnostic Trouble Code (DTC) memory and erase data entries.

-- Remove the engine cover.

-- Clean all fuel rail connections with engine or brake cleaner and dry off.

NOTE:

Follow the rules of cleanliness. The fuel system must remain free of dirt.

Check one cylinder after another.

CAUTION:

Danger of malfunction caused by dirt.

Refer to FUEL SUPPLY SYSTEM SAFETY PRECAUTIONS

Starting with cylinder 1.

-- Remove the fuel supply hoses from the fuel injectors by pressing both retaining straps down while pulling up on the center piece to release -arrow-.

Fig 3: Center Piece On Retaining Strap

Courtesy of AUDI OF AMERICA, LLC

-- Connect the clean adapter that has been cleaned out using compressed air to the fuel return line connection on the injector that is being checked.

-- A vacuum pressure of -500 mbar is applied using the Hand Vacuum Pump VAS6213

Fuel injectors are OK when the pressure remains constant for about 30 seconds.

Fuel injectors are defective when the pressure falls down to 0 bar within 2 to 3 seconds.

Repeat the test if necessary. Watch the Hand Vacuum Pump VAS6213 for a loss of pressure.

-- Replace any defective fuel injectors. Refer to FUEL INJECTORS, REMOVING AND INSTALLING .