Audi Workshop Service and Repair Manuals

Removing and installing injectors Special tools and workshop equipment required

t  Puller -T10055-

t  Assembly sleeve -T10377- t  Puller -T10415- Removing   Caution Risk of malfunctions caused by dirt. Observe → Chapter „Rules for cleanliness and instructions for working on fuel system“. –  Pull off engine cover panel → Chapter.   Caution t  Mark cylinder numbers on injector units. They must always be re-installed on the same cylinders. t  Observe rules for cleanliness when working on the injection system. t  Plug open connections with suitable sealing caps immediately.

–  Pull return line connections off injectors; to do so, press tabs -1- and -2- down and at the same time pull release pin upwards -arrow-.

–  Unplug electrical connectors -arrows- at injectors. –  Loosen union nuts of high-pressure pipes -1 to 4-.

–  Unscrew bolt -1- for clamping piece.   Note Leave clamping piece in position until adjacent injector is detached.   Caution Risk of damage to injector if clamping piece is not kept straight. First detach injectors for cylinders 2 and 4; then detach injectors for cylinders 1 and 3, and at the same time detach clamping piece. –  Apply puller -T10055- with puller -T10415- as shown in illustration, and pull out injector upwards.   Note To avoid damaging the sealing lip, rotate the injector while pulling it out. –  After removal, lay injectors on a clean cloth. Installing new injectors When installing new 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   Note t  Note identification marks for cylinder allocation when re-installing high-pressure pipes. t  The high-pressure pipes can be re-used after performing the following checks: t  Check taper seats of high-pressure pipes for deformation and cracks. t  The bore of the pipe must not be distorted, restricted or otherwise damaged. t  Corroded pipes must not be used again. 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-releasing 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. Do not apply the wire brush to the bores in the nozzle. –  To remove the old copper seal from the injector, clamp the seal carefully in a vice so that it is just held between the jaws without turning. Then carefully pull and twist the injector out of the copper seal by hand. –  Clean off deposits under the copper seal using a suitable scraper.   Caution 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. Take care not to damage the sealing surface.

–  Renew O-ring for injector bore using assembly sleeve -T10377-. –  Install injectors.   Note If injector seals in cylinder head cover are damaged, they must be renewed → Chapter. –  Hand-tighten union nuts on high-pressure pipes. Make sure that connections are not under tension. l  Tightening torques → Chapter „Injectors - exploded view“ –  Press return line connections carefully over seals and onto injectors (check seal for damage before connecting return line). The catch should engage audibly. Then press release pin down carefully. 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. Additionally, check that the „injector delivery calibration values“ and „injector voltage calibration values“ are correctly entered for all the other injectors. Do NOT attempt to re-enter these calibration values if the correct values are already stored in the engine control unit. Bleeding fuel system and checking for leaks   Note The fuel system is self-bleeding; do not open the high-pressure connections. –  Run engine at idling speed for several minutes and then switch off. –  Switch off ignition. –  Check the complete fuel system including all 4 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 check the high-pressure section of the 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.