Audi Workshop Service and Repair Manuals

Removing and installing injectors Special tools and workshop equipment required

t  Removal lever -80 - 200-

t  Puller -T10055- with adapter -T10055/1- and -T10055/3-

t  Socket -T40055- Removing   Note All cable ties which are released or cut open when removing must be fitted in the same position when installing. –  Pull off engine cover panel → Chapter. –  Remove air cleaner housing → Chapter.

Caution Risk of malfunctions caused by dirt. Observe → Chapter „Safety precautions when working on the fuel system“.

–  Unplug electrical connectors at injectors -arrows- and at fuel pressure regulating valve -N276--item 1-. –  Move clear electrical wiring harness at cylinder head cover and fuel rail.

–  Disconnect fuel return hoses from injectors; to do so, press down both tabs and at the same time pull centre piece up to release connection -arrow-.   Caution Used injectors must always be re-installed on the same cylinder. Mark injectors for to ensure that they are re-installed at the correct cylinders.

–  Loosen union nuts -2, 3 and 4- using socket -T40055- and remove high-pressure pipes. –  Seal off open lines and connections with clean plugs.

–  Mark position of clamping piece -1- in relation to injector with paint for re-installation. –  Unscrew bolt -2- and detach clamping piece. –  Repeat work steps on remaining injectors.

–  Apply puller -T10055- with adapter -T10055/1- to injector, as shown in illustration. Pull off injector by tapping gently. –  Place removed injectors on a clean cloth. Installing used injectors When re-installing used injectors, the following components must be renewed: t  Copper seal t  Renew O-ring for injector bore. t  O-ring for fuel return line connection –  Spray tip of injector nozzle with rust-solvent spray. Wait approx. 5 minutes and wipe off soot particles and oil with a cloth. –  If an injector is very dirty, the tip of the nozzle should also be cleaned with a soft brass wire brush to make it easier to remove the copper seal.   Note Take care not to touch the bores in the nozzle with the bristles of the brass wire brush.

–  To detach the old copper seal from the injector, clamp the copper seal carefully using pliers just tight enough to prevent it from turning. –  Then carefully pull and twist the injector out of the copper seal by hand. –  Remove deposits beneath the copper seal with a scraper.   Caution Risk of damage to injector sealing surface. To remove carbon deposits from the injector sealing surface, clean the injector bore in the cylinder head with a cloth soaked in engine oil or rust solvent. Installing new injectors When installing new injectors, the following components must be renewed: t  Clamping piece t  Copper seal t  Renew O-ring for injector bore. t  O-ring for fuel return line connection l  Lubricate all O-rings with engine oil or assembly oil before installing. Continued (same procedure for used and new injectors): –  Use a plastic bush to fit the new copper seal. –  Lubricate all O-rings with engine oil or assembly oil before installing. –  Fit new O-ring for injector bore. Remaining installation steps are carried out in reverse sequence; note the following: –  Install high-pressure pipes → Chapter. –  Connect fuel return hoses. After renewing one or more injectors, the „injector delivery calibration values“ and „injector voltage calibration values“ for the new injectors must be written into the engine control unit → Chapter. Bleeding fuel system and checking for leaks –  Run engine at idling speed for several minutes (do not press accelerator) and then switch off.   Note The fuel system is self-bleeding; do not open the high-pressure connections. –  Switch off ignition. –  Carefully check the complete fuel system including all 6 return line connections for leaks. Renew affected component if leakage still occurs after tightening to correct torque. –  After completing the repair, road-test the vehicle. Accelerate with full throttle at least once. Then inspect high-pressure section of fuel system again for leaks.   Note If there is any air left in the fuel system, the engine may switch to the backup mode ('emergency running' mode) during the road test. Switch off the engine and erase the event memory. Then continue the road test. –  Interrogate the event memory again after road-testing.