Unit Injector, Removing and Installing
Unit injector, removing and installing
Special tools, testers and auxiliary items required
^ Universal dial gauge bracket VW387
^ Socket 3410
^ Socket T1 0054
^ Puller T1 0055
^ Torque wrench (5 ... 50 Nm)
^ V.A.G. 1331
^ Dial gauge
^ Grease G 000 100
Removing
- Remove upper toothed belt guard
- Turn crankshaft until cam lobe pair point upward for unit injector which is to be removed.
- Loosen lock nut of adjustment screw - 1 - and unscrew until relevant rocker arm lies against plunger spring of unit injector.
- Remove rocker arm securing bolts - 2 - (outward to inward) with socket 3410 and take rocker arm shaft off.
- Remove tensioning block securing bolts - 3 - with socket T1 0054 and remove tensioning block.
- Pry connector off unit injector with a screwdriver. Support opposite side of connector using light finger pressure to prevent canting.
- Seat puller into slot on side of unit injector instead of tensioning block.
- Pull unit injector out of cylinder head seat with gentle taps.
Installing
Note:
^ If a new unit injector is installed, the appropriate adjustment screw in the rocker arm must also be replaced.
^ Each time work is performed which requires the unit injector to be adjusted, the adjustment screw in the rocker arm and also the unit injector ball pin must be cleaned and checked for signs of wear. If wear is evident the ball pin and the adjustment screw must be replaced.
^ New unit injectors are supplied with O-rings and heat shield seal.
- Replace heat shield seal and O-rings if old unit injector is reused, O-rings for unit injector, removing and installing .
- Check that three O-rings, heat shield seal and circlip are seating correctly before installing unit injector.
Note: The seals must not be twisted.
- Oil seals and install unit injector into cylinder head with great care.
- Push unit injector evenly into cylinder head onto its limit stop.
- Install tensioning block into slot on side of unit injector.
Note: If the unit injector is not at right angles to the tensioning block the second bolt may loosen and this can damage the unit injector or the cylinder head.
- Align the unit injector as follows:
- Screw new securing bolt into tensioning block until unit injector can still just be turned easily.
- Align unit injector at right angles with camshaft bearing caps.
- Check dimension "a" from outer edge of cylinder head to rounded edge of unit injector with a vernier gauge (measuring range- min. 400 mm).
- If necessary realign unit injector.
- Tighten securing bolts as follows:
- Tighten bolts to 12 Nm and turn 270° 3/4 further (turning further can be done in several stages).
- Install rocker arm shaft and tighten new securing bolts as follows.
- First tighten inner bolts - 2 - and then outer bolts - 1 - hand tight. Then, using same sequence, tighten to 20 Nm and turn 90° (1/4) further.
- Mount dial gauge onto adjustment screw of unit injector as shown.
- Turn crankshaft in engine direction of rotation until roller of rocker arm is positioned on peak of drive cam lobe, roller side - arrow A - is positioned at highest point and dial gauge arrow B - positioned at lowest point.
- Remove dial gauge.
- Turn adjustment screw inward into rocker arm until a firm resistance is felt (unit injector positioned at limit stop).
- Turn adjustment screw approximately 180° back off limit stop.
- Hold adjustment screw in this position and tighten lock nut to 30 Nm.
- Connect unit injector connector and install cylinder head cover.