Audi Workshop Service and Repair Manuals

Removing and installing unit injector Special tools and workshop equipment required t  Universal dial gauge bracket -VW 387- t  Socket -3410- t  Special wrench, long reach -T10054- t  Puller -T10055- t  Torque wrench -V.A.G 1331- t  Workshop vernier caliper -VAS 5276-

t  Torque wrench -V.A.G 1756- Removing –  Remove cylinder head cover: → Rep. Gr.15. –  Turn crankshaft until both cams for the unit injector to be removed/installed point symmetrically upwards.

–  Loosen lock nuts on adjuster screws -1- and turn adjuster screws anti-clockwise until the relevant rocker arm lies against the plunger spring of the unit injector. –  Unscrew bolts -2- for rocker arm shaft (working from outside inwards) using socket 3410 and detach rocker arm shaft. –  Remove clamping block securing bolt -3- with hexagon key -T10054- and remove clamping block.

–  Pry off connector from the unit injector using a screwdriver -arrow-. Press gently against the other side of connector with finger to prevent it from tilting.

–  Apply the puller -T10055- into the slot on the side of the unit injector in place of the clamping block. –  Pull unit injector out of cylinder head seat by gently tapping upwards. Installing   Note t  Whenever an operation requires adjustment of a unit injector, the adjuster screw in the rocker arm and the ball stud of the unit injector must be renewed. t  New unit injectors are supplied with O-rings and insulating seals. t  When installing a new unit injector, you must also renew the appropriate adjuster screw in rocker arm. t  When reinstalling old unit injector, you must renew the O-rings and insulating seals → Chapter. –  Before installing the unit injector, check the three O-rings, insulating seal and retaining ring for correct seating.   Note The O-rings must not be twisted. –  Oil O-rings and fit unit injector in cylinder head seat very carefully. –  Whilst pressing evenly, slide unit injector into cylinder head seat as far as it will go. –  Insert the clamping block in the slot on the side of the unit injector.   Note If the unit injector is not seated at a right angle to the clamping block, the securing bolt may come loose, resulting in damage to the unit injector or cylinder head. –  Therefore, align the unit injector as follows: –  Screw new securing bolt into clamping block, but do not tighten (it must still be possible to turn the unit injector slightly). –  Now align the unit injector at a right angle to the bearing pedestals of the camshaft. –  Using a workshop vernier caliper -VAS 5276- (measuring range at least 400 mm), check dimension “a” from outer edge of cylinder head to rounded surface of unit injector.

Unit injector nut with cylindrical collar:

Cylinder	Dimension “a”
1	244.2 ± 0.8 mm
2	152.8 ± 0.8 mm
3	64.8 ± 0.8 mm

Unit injector nut with bevelled collar:

Cylinder	Dimension “a”
1	245.0 ± 0.8 mm
2	157.0 ± 0.8 mm
3	65.6 ± 0.8 mm

All models: –  Align unit injector as necessary and tighten securing bolt as follows: t  Tightening torque: 12 Nm + 270° (3/4 turn further). –  Fit rocker arm shaft and tighten new securing bolts as follows: –  First tighten inner bolts then outer bolts in several stages. t  Tightening torque in the same sequence: 20 Nm + 90° (1/4 turn further).

–  Fit dial gauge onto adjuster screw of unit injector as shown. –  Turn crankshaft in direction of engine rotation until roller of rocker arm is located at tip of drive cam. t  Roller side -arrow A- positioned at highest point; dial gauge -arrow B- positioned at lowest point –  Remove dial gauge. –  Now turn the adjuster screw into rocker arm until significant resistance can be felt (unit injector is at limit stop).

–  Turn adjuster screw 180° back off limit stop using special tool torque wrench -V.A.G 1756-. –  Hold adjuster screw in this position and tighten lock nut. t  Tightening torque: 30 Nm –  Attach electrical connector for unit injector. –  Install cylinder head cover and toothed belt cover → Rep. Gr.15.