Fuel Rail: Service and Repair
WM 243019 Removing and installing fuel collection pipe (with fuel injectors) - DFI
Tools
Technical values
Preliminary work
1. Read out engine control unit fault memory before getting started.
2. Relieve fuel pressure in the high-pressure system.
2.1. To do this, remove the fuse for the electric fuel pump from the fuse box (passenger compartment).
2.2. Start the engine and allow to run until it cuts out.
3. Switch off ignition and all consumers.
4. Disconnect the battery.
5. Remove resonance tube.
-> 247419 Removing and installing resonance tube Service and Repair.
6. Remove intake-air distributor.
-> 244619 Removing and installing intake-air distributor Service and Repair.
6.1. Cover intake port openings with adhesive tape or a cloth.
Information
Component overview
CAUTION
Dirt on injection system components (intake manifold injection and direct fuel injection system)
- Material damage
- Rough-running engine
- Bad exhaust emissions
-> Thoroughly clean connection points and adjacent areas before loosening them. If the engine is very dirty, wash it before starting disassembly work.
-> Lay removed parts on a clean surface and cover them. Only use a clean, lint-free cloth.
-> Carefully cover components or seal them if repair work will not be carried out immediately. Place rubber caps on connections. Seal intake openings with film or adhesive tape.
-> Only install clean parts. Do not take spare parts out of the packaging until just before installation.
-> Never use compressed air when the system is open. Do not move the vehicle.
Information
- Always perform a leak test in the high-pressure area after opening the fuel system. Testing and Inspection
- This is particularly important if components are disassembled and replaced.
- The threaded connections of the fuel lines must be coated with OKS 1700 lubricant (Part no. 000.043.207.36) before being screwed back on again.
- Blow residual fuel out of the lines and high-pressure pump (into a fuel-resistant container or cloth) using compressed air before installation.
- The tightening specifications must be strictly observed.
Overview of fuel system in engine compartment
Overview of fuel system - DFI
Removing fuel collection pipe (with fuel injectors)
WARNING
Highly inflammable or explosive materials
- Danger of fire or explosion
-> Avoid contact with hot parts or sources of ignition.
-> Use suction to remove ignitable vapours.
-> Attach warning sign in a clearly visible position.
1. Observe safety instructions when working on the fuel system.
Information
- Only work on the fuel system when the engine is cold.
2. Disconnect fuel connection line between the fuel collection pipes.
-> 249019 Removing and installing fuel connection line .
2.1. Cover intake ports on the cylinder head and place a clean, lint-free cloth under the fuel collection pipe and high-pressure connecting line -3-.
2.2. Soak up emerging fuel with the cloth.
2.3. Loosen two union nuts -1- using an open-ended wrench (a/f 17) -2-.
Threaded connections for fuel high-pressure line on side 1-3
2.4. Loosen union nut -1- using an open-ended wrench (a/f 17) -2-.
Threaded connection for fuel high-pressure line on side 4-6
2.5. Loosen clamps -1- on the connecting line. To do this, unscrew one external Torx screw (E10, M6 x 12) on each clamp.
Clamps for connecting line
3. Remove fuel collection pipe (side 1-3 or 4-6).
3.1. Unclip cable duct.
3.2. Pull off cable plug for fuel injectors.
3.3. Unscrew four external Torx screws (E10, M6 x 30) -1- used to secure the fuel collection pipe -2-.
Threaded joint for fuel collection pipe
Information
- When removing and installing the high-pressure fuel injectors, the following components must always be replaced to guarantee function and leaktightness.
- O-ring, spring clamp, bellows and Teflon sealing ring.
4. Pull off spring clamps -1- on the fuel injectors using a pair of small flat-nosed pliers if possible.
4.1. If this is not possible because they are inaccessible, pull out fuel collection pipe using the fuel injectors.
4.2. If this is not possible because the fuel injectors are stuck (metal corrosion between stainless steel and aluminium), spray valve seats with anti-rust agent (e.g. WD 40 or Caramba) and leave it to take effect.
Remove excess anti-rust agent with a cloth.
4.3. Carefully move the fuel collection pipe back and forth. Then push a plastic or wooden wedge (shop made) under the pipe and lift it.
4.4. Lift the module with the fuel injectors out of the engine compartment.
4.5. Remove spring clamps, pull fuel injectors out of the pipe adapter as vertically as possible (axially).
4.6. Always replace the spring clamps.
Fuel injector spring clamp
5. One or more fuel injectors -1- can remain in the cylinder head, depending on the age of the vehicle.
5.1. The spring clamps become loose and fall into the engine compartment when the fuel collection pipe is pulled off. Remove these immediately.
Fuel injectors in cylinder head
6. Pull fuel injector out of its seat in the cylinder head. Use special tool repair kit T10133 with puller arms for T10133/1 - kit T10133/30 to do this.
6.1. Free fuel injector using a twisting motion.
6.2. Puller arms for T10133/1 - set T10133/30 must be positioned on the fuel injector -2-. To do this, insert the lever arms into the cut-outs on the injector -arrow- and lock them by screwing the hexagon nut -1- clockwise.
Puller arms on fuel injector
6.3. Screw slide hammer from the repair kit onto the hexagon nut -1-. Press lever arms -2- together and remove the injector by pulling up gently.
Detaching fuel injector (view of side 1-3)
Side 4 -6:
Detaching fuel injector (view of side 4-6)
6.4. Tool on injector:
Special tool at injector
7. Carefully clean fitting bores on cylinder head.
7.1. Remove loose parts using a powerful workshop vacuum cleaner.
7.2. Soak a small, clean and lint-free cloth in acetone or solvent naphtha and carefully clean the bores.
7.3. Use the cleaning brush from the tool set to remove any remaining dirt from the fitting bores.
8. Clean fuel collection pipe.
8.1. Clean connection piece for the fuel injectors with acetone or solvent naphtha.
9. Fuel injectors that are to be reinstalled must also be cleaned (see Cleaning fuel injectors).
Cleaning fuel injectors and replacing wearing parts
Component overview
Individual components of fuel injector
Information
- When removing and installing the high-pressure fuel injectors, the following components must always be replaced to guarantee function and leaktightness.
- O-ring, spring clamp, bellows and Teflon sealing ring.
1. Hold Teflon sealing ring carefully using pointed-nose pliers and pull it off -1-. Do not scratch valve body.
Removing Teflon sealing ring
1.1. Scratched valves must be replaced.
2. When reinstalling the fuel injectors, they must be cleaned as described below:
WARNING
Caustic fluids
- Danger of chemical burns
-> Avoid contact with caustic fluid.
-> Wear personal protective gear.
-> Ensure that there is good ventilation.
-> If you do come into contact, wash off immediately with plenty of warm water and contact a doctor if necessary.
Cleaning if lightly soiled:
3. Clean valve tips using a soft, lint-free cloth with acetone or solvent naphtha.
3.1. Also clean sealing ring groove.
Cleaning if heavily soiled:
4. Clean valve tips in ultrasound bath. This allows even stubborn deposits (coking) to be removed.
4.1. Plunge just the metal insert into the cleaning fluid as vertically as possible. Cover electric plug connectors with adhesive tape.
5. Replace O-ring and bellows.
6. Place new Teflon sealing ring -2- onto mounting cone no. 5 -1-. Push sealing ring onto cylinder of mounting cone right to the end -item 3- using your thumb and index finger -arrow-.
Pushing on Teflon ring
7. Place mounting cone -1- with sealing ring onto the fuel injector from the front. Using assembly sleeve no. 8 -2- push sealing ring over the injector tips as far as the groove.
Fitting Teflon sealing ring
7.1. The sealing ring is not yet seated correctly in its groove.
8. Remove assembly sleeve and mounting cone. Align sealing ring in the ring groove.
8.1. Push assembly sleeve up to the ring groove and join the sealing ring to the bore of the assembly sleeve by hand.
Pushing Teflon sealing ring into ring groove
8.2. Calibrating Teflon sealing ring:
8.3. Press assembly sleeve -1- over the sealing ring and as far as it will go.
Leave tool on the sealing ring for one minute.
Assembly sleeve for calibrating Teflon sealing ring fitted
8.4. Detach tool again.
The Teflon sealing ring now has the correct installation dimension.
9. The fuel injector should now be installed immediately, as the Teflon sealing ring will soon start to swell (prevents leaks when installed).
9.1. However, all three valves must first be fitted and aligned in the fuel collection pipe before the fuel connection pipe can be re-installed.
9.2. The dowel sleeve -2- for a new injector (transport sleeve for new injectors) must therefore be pushed onto the valve and only removed again just before installation.
9.3. The Teflon ring will otherwise lose its shape and will be compressed when installed. This would result in leaks.
Installing fuel collection pipe (with fuel injectors)
Tightening specifications for fuel collection pipe and fuel line
1. Tightening specifications for fuel collection pipe:
1.1. First position screws -1 and 2- by hand (intake port side).
1.2. Then tighten screws -3 and 4- by hand.
1.3. Tighten all screws to torque in accordance with numbered sequence.
=> Tightening torque: 13 Nm (9.5 ftlb.)
Tightening sequence for fuel collection pipe
2. Tightening specifications for fuel connection line:
2.1. Coat all threaded connections with lubricant OKS 1700 (part no. 000.043.207.36). To do this, immerse the ends of the line in the lubricant, coat connection at item 3 with a paintbrush.
2.2. Tighten union nuts (a/f 17) -1 and 2- by hand.
2.3. Tighten connection -3- by hand.
2.4. Tighten clamps -4 and 5- with M6 screws.
=> Tightening torque: 10 Nm (7.5 ftlb.)
2.5. Tighten union nuts -1 and 2-.
=> Tightening torque: 20 Nm (15 ftlb.)
2.6. Tighten union nut (a/f 17) -3-.
=> Tightening torque: 20 Nm (15 ftlb.)
Tightening sequence for connecting line
Installing fuel collection pipe (with fuel injectors)
1. Grease the three take-up flanges for the fuel injectors on the fuel collection pipe with assembly grease VP 881 (Part No. 000.043.207.35).
2. Position fuel injectors -1- in the fuel collection pipe -2- for fitting the spring clamps. Only press the valve in as far as the upper edge -arrow- when doing this.
2.1. Always press the valve vertically (axially) into the take-up flanges.
Position of fuel injector for assembling spring clamps
3. Fit new spring clamps.
3.1. Slide spring clamp -1- over the mount and fuel injector from behind. The twist-lock must fit into the eyelet -arrow-.
Aligning installation position of fuel injector with spring clamp (twist-lock)
3.2. Hook in spring clamp -1- on either side on the fuel connection pipe mount -arrow-.
Fuel injector spring clamp
4. Pull off dowel sleeves -2- on the fuel injectors.
Assembly sleeve for calibrating Teflon sealing ring fitted
5. Insert particular fuel collection pipe with fuel injectors at cylinder head.
5.1. Fit fuel collection pipe according to tightening specifications.
6. Fit fuel connection line according to tightening specifications.
-> 249019 Removing and installing fuel connection line .
Subsequent work
WARNING
Leaking fuel supply lines
- Emerging fuel
- Risk of fire
-> Perform leak test. Testing and Inspection
1. Perform leak test. Testing and Inspection
-> 200101 Checking fuel system (high-pressure side) for leaks Testing and Inspection.
WARNING
Caustic fluids
- Danger of chemical burns
-> Avoid contact with caustic fluid.
-> Wear personal protective gear.
-> Ensure that there is good ventilation.
-> If you do come into contact, wash off immediately with plenty of warm water and contact a doctor if necessary.
2. Remove adhesive residue on sealing faces of intake ports with acetone if necessary.
3. Install intake-air distributor.
-> 244619 Removing and installing intake-air distributor Service and Repair.
4. Install resonance tube.
-> 247419 Removing and installing resonance tube Service and Repair.
5. Connect the battery.
-> 2X00IN02 Work instructions after disconnecting the battery Work Instructions After Disconnecting the Battery.
6. Use the PIWIS Tester 9718 to perform the First Start function.
-> 2001IN Bleeding fuel system high-pressure side (First Start function) Service and Repair.
7. Perform a test drive.