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	Depth gauge (measuring range at least 400 mm)

Removing –  Remove cylinder head cover → Rep. Gr.15. –  Turn crankshaft until both cams for the unit injector to be removed face upwards.

–  Loosen the lock nuts of the adjuster screws -1- on all unit injectors. –  Unscrew the adjuster screws until each rocker arm touches the tappet spring of the unit injector. –  Remove rocker arm shaft by unscrewing bolts -2- using socket -3410- starting from the outside working inwards. –  Unscrew bolt -3- for clamping block using socket -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 and adjusting   Note t  Renew bolts on unit injectors. 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. 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 cleaned and examined for signs of wear. Ball stud and adjuster screw must be renewed if signs of wear are found. t  Grease the contact surfaces between the ball stud and adjuster screw with lubricating grease -G 000 100-. –  Before installing the unit injector, check the three O-rings, insulating seal and retaining ring for correct seating. l  The O-rings must not be twisted. –  Lubricate O-rings and guide in cylinder head with oil. –  Insert unit injector very carefully into cylinder head seat and press in 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.

–  Check dimension -a- from outer edge of cylinder head to rounded edge of unit injector with a depth gauge (measuring range at least 400 mm.)

Cylinder	Dimension -a-
1	333.0 ± 0.8 mm
2	245.0 ± 0.8 mm
3	153.6 ± 0.8 mm
4	65.6 ± 0.8 mm

–  If necessary, adjust the unit injector and tighten the securing bolt as follows: l  Tightening torque: 12 Nm + 270° (3/4 turn further). –  First tighten inner bolts -2- and then outer bolts -1- in several stages. l  Tightening torque: 20 Nm + 90° (1/4 turn further).

–  Place a dial gauge on adjuster screw of unit injector, as shown in illustration. –  Turn crankshaft in direction of engine rotation until roller of rocker arm is located at tip of drive cam. l  Roller side -arrow A- is at highest point. l  Dial gauge -arrow B- is 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 stop. –  Hold adjuster screw in this position and tighten lock nut to 30 Nm. Remaining installation steps are carried out in reverse sequence; note the following: –  Attach connector for unit injector. –  Install cylinder head cover → Rep. Gr.15.