Component overview

1. Spring clamp - always replace
2. O-ring - always replace
3. Fuel injector - follow cleaning instructions
4. Bellows with stainless steel circlip - always replace
5. Spacer ring
6. Circlip
7. Teflon sealing ring
   Fig 1: Identifying Fuel Injector Components

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Information 

• When removing and installing the 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.
   Fig 2: Removing Teflon Sealing Ring

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   1. 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.
   1. 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.
   1. 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-  .
   Fig 3: Pushing Teflon Ring

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
7. Fit mounting cone -1-  with sealing ring onto the fuel injector from the front. Use assembly sleeve no. 8 -2-  to push the sealing ring over the injector tip as far as the groove.
   Fig 4: Fitting Teflon Sealing Ring

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   1. 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.
   1. 8.1. Push assembly sleeve up to the ring groove and join the sealing ring to the bore of the assembly sleeve by hand.
      Fig 5: Pushing Teflon Sealing Ring Into Ring Groove

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   2. 8.2. Calibrating Teflon sealing ring: 
   3. 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. 

      Fig 6: Identifying Assembly Sleeve And Teflon Sealing Ring

      Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   4. 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).
   1. 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.
   2. 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.
   3. 9.3. The Teflon ring will otherwise lose its shape and will be compressed when installed. This would result in leaks.