Fuel Injector: Service and Repair

Fuel Injectors

Special tools, testers and auxiliary items required

• Tool set (T10133)

High-Pressure Fuel Injector - Component Overview





1. Radial adjustment - Replace if damaged

2. Combustion chamber seal (Teflon seal) - replace, the seal must not be greased or be handled with any other lubricant during installation

3. Groove on fuel injector

4. Spacer ring - Replace if damaged

5. O-ring - replace, lightly coat with clean engine oil during installation

6. Support ring - fuel rail wields force via support ring to hold fuel injector tightly in cylinder head

Removing

CAUTION!
• Fuel system is under high pressure! Before opening high pressure components of the fuel injection system, pressure must be relieved to residual pressure => [ High-Pressure Fuel Injection System, Pressure Relief ] Service and Repair.

• Then wrap a clean rag around the connection and relieve residual pressure by carefully loosening the connection.

- Remove upper part of intake manifold => [ Upper Intake Manifold ] Upper Intake Manifold.

- Remove corresponding intake manifold lower-part => [ Lower Intake Manifold with Fuel Rail ] Lower Intake Manifold with Fuel Rail.

If fuel injectors cannot be pulled out of cylinder head by hand, proceed as follows:





- Using a screwdriver, bend retaining tabs - 1 - of radial adjustment aside - arrow - and pull support ring - 2 - from fuel injector.

- Attach slide wrench (T10133/3) with adapter (T10133/2).





- Guide puller (T10133/2) into groove on fuel injector and carefully drive fuel injector out.

• When setting the puller in place, the radial adjustment can be destroyed, because the retaining tabs break.

- Carefully remove old combustion chamber seal - arrow -, thereby cutting seal open with a knife or spreading seal open with a small screwdriver and pulling it forward and off.





- Make sure that the groove of fuel injector does not become damaged. If groove is damage, fuel injector must be replaced.

Installing

• Replace combustion chamber seal and O-ring.

• Replace spacer ring if damaged.

• Lightly moisten fuel injector O-rings with clean engine oil.

• Re-insert injector lines at same cylinder.

- Clean bore in cylinder head with nylon cylinder brush (T10133/4).





- Clip radial adjustment - 1 - to support ring - 2 -.





- When reinstalling a fuel injector, use a clean cloth to clean combustion residue from groove for combustion chamber seal and shaft of fuel injector.

- Place assembly cone (T10133/5) with new combustion chamber seal - 1 - on fuel injector - 2 -.





- Slide combustion chamber seal as far possible onto assembly cone (T10133/5) using assembly sleeve (T10133/6).





- Turn assembly sleeve (T10133/6) around and slide combustion chamber seal into groove.

• When pushing the combustion chamber seal onto the fuel injector, the seal spreads open. Therefore after pushing it on, it must be tightened again in 2 steps, as follows.

- Press sizing sleeve (T10133/7) with a slight turning motion (approximately 180 degrees) onto fuel injector until it stops.





- Pull sizing sleeve (T10133/7) off again, turning it in opposite direction.

- Press sizing sleeve (T10133/8) with a slight turning motion (approximately 180 degrees) onto fuel injector until it stops.





- Pull sizing sleeve (T10133/8) off again, turning it in opposite direction.

- Moisten new O-ring 3 with clean engine oil before installing.

• The combustion chamber seal must not be oiled.

- Slide fuel injector into bore cylinder head as far as stop using assembly drift (T10133/9).





• The fuel injector must not be difficult to install. If necessary, wait as the combustion chamber seal continues to pull itself together.

- Make sure fuel injectors are correctly positioned in cylinder head.

• The electrical connection of fuel injector must engage in intended recess of cylinder head.

Further installation is in reverse order of removal, note the following:

- Install intake manifold lower-part => [ Lower Intake Manifold with Fuel Rail ] Lower Intake Manifold with Fuel Rail.

- Install intake manifold upper-part => [ Upper Intake Manifold ] Upper Intake Manifold.