Fuel Injectors
Fuel Injectors
Special tools, testers and auxiliary items required
• Puller (T10055)
• Guide Sleeve (T10377)
• Puller (T10415)
Removing
• Follow the guidelines for a clean working environment when working on the fuel system. Refer to => [ Clean Working Conditions ] Clean Working Conditions.
• Always follow these rules before and during work.
- Remove the engine cover. Refer to => [ Engine Cover ] Engine Cover.
• Mark the allocation of the injectors to the cylinder. They must always be reinstalled to the same cylinder.
• Note rules of cleanliness for working on the fuel injection system.
• Always seal any open connections with a suitable cover.
- Push both brackets - 1 and 2 - down and at the same time pull the release upwards - arrow - and remove the return line connection from the fuel injector.
- Disconnect electrical connectors - arrows - from all the fuel injectors.
Counter hold the high pressure support with a open end wrench when loosening the high pressure line. If the high pressure supports are loosened, it may cause leaks.
- Loosen the union nuts for each high pressure line - 1 through 4 - and remove the high pressure lines.
- Remove the tensioning bracket bolt - 1 - for the fuel injector to be removed.
- Attach the puller (T10055) to the puller (T10415) and remove the injector upward using a knocking motion.
• Remove the fuel injector with a turning motion in order to avoid damaging the sealing lip.
- Place the injector on a clean cloth.
Important information on installing the fuel injector:
• Replace the following components and seals or O-rings with each removal and installation: "copper washer" "injector shaft O-ring" "injector return O-ring".
• The following components and seals and/or O-rings must be replaced whenever an fuel injector is replaced: "tensioning bracket" "copper washer" "fuel injector shaft O-ring" "fuel injector return O-ring".
• Lubricate all of the O-rings with assembly oil or engine oil before installing.
• When reusing the high pressure line again, pay attention to the cylinder marks.
• The high pressure line can be reused only after the following checks:
• Check the sealing cone on each high pressure line for deformation and cracks.
• The bores for the line must not be deformed, narrowed or damaged.
• Do not reuse any corroded lines again.
If a used fuel injector is installed:
- Spray the tip of the fuel injector with a rust removing spray. Remove the rust or oil particles with a cloth after approximately 5 minutes.
- To remove the used copper washer from the fuel injector, clamp the washer carefully in a vise, until the clamping jaws on the vise prevent the washer from turning. Pull the fuel injector out of the copper washer by hand with a slight twisting and pulling motion.
To remove rust particles on the fuel injector sealing surface, clean the fuel injector bore in the cylinder head with a cloth dampened with engine oil or rust remover. Do not damage the sealing flanges.
- Replace the fuel injector shaft seal using the guide sleeve (T10377).
- Carefully slide the lubricated O-ring onto the fuel return line connection to prevent damaging it.
- Install the fuel injectors.
- Tighten the high pressure line union nut by hand. Make sure it fits free of tension.
• For the correct tightening specification, refer to => [ Fuel Rail and Injector Overview ] Fuel Rail and Injector Overview.
- Press the return line connection carefully over the sealing ring onto the injector (check the sealing ring first for damage). The connection must engage audibly. Then press the release pin down carefully.
The correction values for the new injectors must be must be programmed into the Engine Control Module (ECM) after replacing one or more injectors. Refer to the vehicle diagnostic tester.
Check all the other injectors as well to make all their correction values have been entered correctly. If the correct comparison value have been stored in the ECM, then these comparison value must never be reentered.
- Bleed the fuel system. Refer to => [ Fuel System, Filling and Bleeding ] Fuel System, Filling and Bleeding.
• The high pressure connections must not be opened.
- Allow the engine run a few minutes at idle and then stop it.
- Turn off the ignition.
- Check the entire fuel system and the 4 return line connections for leaks, refer to => [ Fuel System, Performing Leak Test ] Fuel System, Performing Leak Test.
If there are leaks even though the correct tightening specification was used, replace the affected component.
• The return lines may only be replaced completely with the check valve.
- Take the vehicle on a 20 km (12.4 mile) road test using full throttle at least one time. Then check the high pressure area one more time for leaks.
• If there is still air in the fuel system, the engine may switch to emergency mode during the road test. Turn off the engine and erase the Diagnostic Trouble Code (DTC) memory. Refer to the vehicle diagnostic tester. Continue the road test.