Volkswagen 4-cyl. injection engine (1.8 and 2.0 l engine, chain drive). Manual (Edition 08.2018)

– Disconnect vacuum line -arrow- to activated charcoal filter.
– Disconnect the following electrical connectors:
♦ Intake air temperature sender - G42- -1-
♦ Throttle valve module - J338- -2-
♦ Activated charcoal filter solenoid valve 1 - N80-
♦ Hall sender - G40-

– Disconnect vacuum line -1- at connecting point -2- and remove

the crankcase breather hose -3-.

– Unscrew bolts -arrows- for fuel supply pipe and lay pipe to

side.

475

WARNING

The fuel system is pressurised.
Danger of injury caused by fuel spray.

♦ Wear protective goggles.
♦ Wear protective gloves.
♦ To release pressure, wrap a clean cloth around the con‐

nection and carefully loosen the connection.

– Unscrew fuel pipe union nut -lower arrow-.

– Pull vacuum pipe -arrow- from intake manifold flap valve -

N316- .

– Unscrew coolant line bolts -arrows- from intake manifold.

– Pull electrical connector -1- from fuel pressure sender -

G247- .

Rep. gr.24 - Mixture preparation - injection

– Remove throttle valve module - J338- -arrows-.

– Remove intake manifold support; to do this, unscrew securing

nut -1- and unscrew bolt -2-.

– Removing oil filter

Engine codes CAWA, CAWB, CBFA, CCTA, CCTB, BZB,

CGYA

⇒ page 225

Engine codes CCZA, CCZB, CCZC, CCZD, CDAA, CDAB

⇒ page 229

– Detach cable retainer -arrows-.

– Detach cables -arrows- from intake manifold.

Rep. gr.24 - Mixture preparation - injection

– Unscrew nuts -A- and remove bolts -arrows- for intake mani‐

fold using socket Torx T30 - T10347- .

– Carefully pull intake manifold with fuel rail slightly away from

cylinder head.

– Disconnect electrical connector -arrow- from intake manifold

flap potentiometer - G336- and remove intake manifold.

– Seal intake ports with a clean cloth.

Note

The injectors can remain in the fuel rail.

– Disconnect fuel rail from intake manifold

⇒ page 480

Installing:
• Injectors must be installed in cylinder head. Installing injectors

⇒ page 481

– Fit intake manifold onto studs (left and right) on cylinder head.

Note

Observe correct installation position of injectors and on cable re‐

tainer (below intake manifold) when positioning intake manifold.

• If, during intake manifold installation, the intake manifold has

to be pulled out again slightly and the injectors remain in the

fuel rail, Then pull the injectors out from the fuel rail again and

again insert the injectors into the cylinder head.

Further assembly is performed in the reverse order of removal.

During this procedure, observe the following:

– On engaging cable retainer onto intake manifold, also clip in

the other two retainers.

Specified torques: refer to assembly overview of intake manifold

⇒ page 469

Specified torques: refer to assembly overview of fuel rail

⇒ page 472

479

2.9.1

Removing and installing fuel rail

Note

Intake manifold must be removed; removing intake manifold

⇒ page 473

– Pull activated charcoal filter system solenoid valve 1 - N80-

-arrow- from retainer.

– Loosen non-return valve -1- and fuel line -2-.

– Open hose clip -1-.
– Remove both bolts -arrows- from fuel rail.
– Pull off fuel rail from intake manifold.

Installing
– Push fuel rail -1- into supports -2- to stop.
– Push fuel rail in -direction of arrow- so that fuel rail engages in

retaining lugs -3- on top of intake manifold.

Rep. gr.24 - Mixture preparation - injection

– Tighten both bolts -arrows- from fuel rail.
– Install non-return valve and fuel line.
– Continue installation in reverse order of removal.
– Re-connect electrical connectors.
– Install intake manifold

⇒ page 473

Specified torques

Adapter for fuel line to fuel rail (renew)

40 Nm

Fuel line (union nut) to adapter for fuel rail

27 Nm

2.10

Removing and installing injectors

Special tools and workshop equipment required
♦ Tool set - T10133-

Note

Puller - T10133/2- has been modified and is now designated pull‐

er - T10133/2A- . If the new tool is not yet available in the

workshop, perform the modification yourself.

Convert puller - T10133/2- tool to puller - T10133/2A- tool.
Special tools and workshop equipment required
♦ Round file approx. 6 mm
– File out a semi-circular recess as shown in the illustration. The

recess allows the tool to be pushed further onto the injector so

the contact surface is increased.

– For identification purposes, mark the modified tool with the

letter “A” after the tool number.

481

Injector (old version)
1 - Combustion chamber ring seal (Teflon ring seal), renew; when

fitting, do not grease ring or use any other lubricant.
2 - The support ring must be replaced with an intermediate ring.

See Injector (new version)
3 - Injection valve
4 - Spacer (renew if damaged)
5 - O-ring (renew; to install, lightly lubricate with clean engine oil).
6 - Support ring (via this support ring, the fuel rail exerts force

which secures injector in cylinder head)

Injector (new version)
1 - Replace intermediate ring
2 - Support bearing
3 - Combustion chamber ring seal (Teflon ring seal), renew; when

fitting, do not grease ring or use any other lubricant.
4 - Injection valve
5 - Spacer (renew if damaged)
6 - O-ring (renew; to install, lightly lubricate with clean engine oil).
7 - Support ring (via this support ring, fuel rail exerts force which

secures injector in cylinder head)
Removing:
– Remove intake manifold with fuel rail

⇒ page 473

Note

If the injectors remain in the fuel rail, pull them out of the fuel rail.

– Seal intake ports with a clean cloth.

– Remove supporting element -A- and pull off connectors

-arrows- from injectors.

Rep. gr.24 - Mixture preparation - injection

– Apply puller -T10133/2A- to groove on injector.
– Position removal tool -T10133/16- and pull injector out by turn‐

ing bolt -1-.

Note

♦

Note the intermediate rings.

♦

The Teflon seal must always be renewed prior to reinstallation

of the injector

⇒ page 484

Installing:

Note

♦

Do not oil or grease the Teflon seal on the injector.

♦

It is possible that an open inlet valve hinders cleaning. In this

case, turn engine by hand at crankshaft using a spanner.

– Thoroughly clean holes of high-pressure injectors in cylinder

head using a nylon brush - T10133/4- .

– Renew Teflon seal of injector

⇒ page 484

– Complete injector with parts from the repair set.

– Push injector by hand as far as it will go into the hole of the

cylinder head (free of oil and grease). Ensure injectors are

positioned correctly -arrow- in cylinder head.

Note

If it is not possible to insert the injector by hand, use the puller -

T10133/2A- -2- with a hammer - T10133/3- to insert the injector.

– Fit support ring onto injector.
– Lightly moisten O-rings of the high-pressure injector with clean

engine oil.

– Install intake manifold with fuel rail

⇒ page 473

483

2.11

Renewing Teflon seal on injector

Special tools and workshop equipment required
♦ Tool set - T10133-

Note

Do not lubricate the Teflon ring.

– Carefully remove old Teflon ring using suitable tools (e.g. cut

open ring using razor blade, or prise open ring with small

screwdriver and then pull off forwards). It is essential to ensure

that the groove and continuous ridge in groove surface are not

damaged.

– Carefully clean injector in area of seal -arrow-. Remove coking

deposits using a brass wire brush.

– Clean groove for seal.

– Fit new seal onto assembly cone - T10133/5- . Push seal as

far as possible onto assembly cone - T10133/6- using assem‐

bly sleeve - T10133/5- .

Rep. gr.24 - Mixture preparation - injection

– Turn assembly sleeve - T10133/6- around and push seal to

end of assembly cone - T10133/5- .

– Fit assembly cone - T10133/5- on injector and push seal onto

injector using assembly sleeve - T10133/6- .

– Remove assembly cone - T10133/5- and push seal into

groove using assembly sleeve - T10133/6- .

– Push calibration sleeve - T10133/7- onto injector as far as it

will go and simultaneously turn it slightly (approx. 180°).

– Pull calibration sleeve - T10133/7- off again by turning it in the

opposite direction.

– Now press calibration sleeve - T10133/8- onto injector to stop

by turning gently (approx. 180°).

– Pull calibration sleeve - T10133/8- off again by turning it in the

opposite direction.

– Renew O-ring and support washer on injector.

2.12

Cleaning injectors

Special tools and workshop equipment required
♦ Ultrasonic cleaning device - VAS 6418-
♦ Mounting plate for injection modules - VAS 6418/1-
♦ Cleaning fluid - VAS 6418/2-

485

Cleaning
– Remove injectors

⇒ page 481

Note

Comply with safety regulations and instructions for ultrasonic unit.

– The ultrasonic unit must be filled with cleaning fluid - VAS

6418/2- .

Note

The ultrasonic unit must be filled with cleaning agent to upper

edge of holes (see detail).

– Insert injectors -1- into mounting plate for injection modules -

VAS 6418/1- as far as stop -2-.

– Dip injectors together with mounting plate for injection mod‐

ules - VAS 6418/1- into cleaning fluid.

– Set a temperature of 50 degrees with the rotary knob -4-.
– Set the rotary knob -5- to a cleaning time of 30 minutes.
– Switch the ultrasonic unit on with button -3-.

Note

As soon as the cleaning temperature is 50 degrees, the set time

will begin to elapse.

– After cleaning, always replace combustion chamber ring seal

(Teflon seal) for each injector

⇒ page 484

– Then reinstall injectors

⇒ page 481

2.13

Removing and installing fuel pressure

sender - G247-

Special tools and workshop equipment required
♦ Assembly tool - T10118-

Rep. gr.24 - Mixture preparation - injection

– Release connector from fuel pressure sender - G247- using

assembly tool - T10118- .

WARNING

The fuel system is pressurised.
Danger of injury caused by fuel spray.

♦ Wear protective goggles.
♦ Wear protective gloves.
♦ To release pressure, wrap a clean cloth around the con‐

nection and carefully loosen the connection.

– Unscrew fuel pressure sender - G247- using deep hexagon

socket, 27 mm - VAS 5301/7- .

– Collect escaping fuel with a cleaning cloth.
Installing:
Install in reverse order of removal, observing the following.
Lubricate sealing cone of fuel pressure sender - G247- with clean

engine oil.
– Specified torques

⇒ page 472

2.14

Removing and installing throttle valve

module - J338-

Removing:
Vehicles with sound generator:
– Remove charge air duct to sound generator

⇒ page 455

Golf, Eos, Scirocco:
– Remove radiator cowl

⇒ page 273

All:
– Release hose clip -2-.
– Unscrew bolt -4-.
– Separate electrical connector -arrow-.
– Remove noise insulation ⇒ General body repairs, exterior;

Rep. gr. 50 ; Noise insulation .

– Remove air pipe -item 1 and 2-.

Rep. gr.24 - Mixture preparation - injection

– Remove bolt -1- and take out air pipe downwards.

– Separate electrical connector -1- on throttle valve module -

J338- .

– Remove bolts -arrows- and detach throttle valve module -

J338- .

Installing:
Install in reverse order of removal, observing the following.
Specified torques

⇒ page 469

– Clean sealing surface for O-ring.
– Renew gasket, making sure that service lug is correctly posi‐

tioned on oil seal.

– If a new throttle valve module - J338- was installed, adapt the

engine control unit to throttle valve module - J338- ⇒ Vehicle

diagnostic tester “Guided Functions”.

2.15

Cleaning throttle valve module - J338-

Special tools and workshop equipment required
♦ Acetone

Note

♦

Observe rules for cleanliness

⇒ page 280

♦

When cleaning the throttle valve housing, take care not to

scratch it.

Procedure:
– Remove throttle valve module

⇒ page 488

– Open throttle valve by hand and block throttle valve in open

position with a suitable object -arrow-.

WARNING

Acetone is highly inflammable. Please comply with the acci‐

dent prevention regulations and the safety instructions when

handling highly inflammable fluids. Do not use compressed air

when cleaning the throttle valve. Wear protective goggles and

protective clothing to avoid injury and contact with the skin.

489

– Thoroughly clean throttle valve housing, especially around

closed throttle valve, using commercially available acetone

and a cleaning brush.

– Wipe off throttle valve housing using a lint-free cloth.
– Allow acetone to evaporate completely and re-install throttle

valve module after cleaning.

– Adapt the engine control unit to throttle valve module ⇒ Vehicle

diagnostic tester “Guided Functions”.

2.16

Assembly overview - high-pressure

pump with fuel pressure regulating valve

- N276-

Note

Note that there are different versions of fuel high pressure pipe

connecting pieces.

1 - O-ring

❑ Renew

2 - Roller tappet

❑ May remain inserted in

vacuum pump after re‐

moval of high-pressure

pump, removable

3 - Fuel high pressure pipe

connecting piece (with inner

thread)

❑ 25 Nm
❑ Counter-hold connec‐

tion when loosening un‐

ion nut.

❑ If the union nut or the

connection is detached,

the connection must be

renewed.

4 - Fuel high pressure pipe

connecting piece (with outer

thread)

❑ 40 Nm
❑ Counter-hold connec‐

tion when loosening un‐

ion nut.

❑ If the union nut or the

connection is detached,

the connection must be

renewed.

5 - Union nut for fuel high pres‐

sure pipe

❑ Counter-hold connec‐

tion when loosening un‐

ion nut.

Rep. gr.24 - Mixture preparation - injection

❑ If the union nut or the

connection is detached, the connection must be renewed.

❑ Specified torques with installed connection at position 3: 18 Nm
❑ Specified torques with installed connection at position 4: 27 Nm

6 - Fuel pressurisation line from fuel tank
7 - Bolts for high-pressure pump

❑ Renew
❑ M6 thread = 8 Nm + 90°
❑ M8 thread = 20 Nm.

8 - High-pressure pump

❑ With fuel pressure regulating valve - N276- .
❑ When installing the high-pressure pump, ensure that no dirt enters the fuel system
❑ Install fuel line to fuel rail without tension

9 - Fuel pressure regulating valve - N276-

❑ Part of the high-pressure pump

2.17

Removing and installing high-pressure

pump

Note

♦

The high-pressure pump should be removed and installed only

when the engine is cold.

♦

When installing the high-pressure pump, it is essential to en‐

sure that no dirt enters the fuel system.

♦

Catch escaping fuel with a cleaning cloth.

♦

The O-ring and the union must always be renewed.

♦

Always ensure that high-pressure fuel lines are free of stress

when installed.

Removing
– Remove engine cover panel

⇒ page 141

– Remove air filter housing

⇒ page 467

– Pull electrical connector -2- from fuel pressure regulating valve

- N276- .

491

WARNING

The fuel system is pressurised.
Danger of injury caused by fuel spray.

♦ Wear protective goggles.
♦ Wear protective gloves.
♦ To release pressure, wrap a clean cloth around the con‐

nection and carefully loosen the connection.

– Open both fuel pipes -arrows-.

– Unscrew 2 bolts -arrows-.
– Carefully pull out fuel high-pressure pump. Under certain cir‐

cumstances, the roller tappet may become stuck in the cylin‐

der head.

Installing

Note

♦

Roller tappet must be at bottom dead centre to enable high-

pressure pump to be installed.

♦

The connection for fuel supply line (high-pressure side) must

be renewed. See assembly overview for high pressure pump

⇒ page 490

♦ Specified torques

⇒ page 490

– Renew O-ring for high-pressure pump.
– Insert roller tappet in vacuum pump (first check roller tappet

for damage).

– Turn crankshaft until roller tappet is at bottom dead centre.
– Insert high pressure pump in vacuum pump.
– Tighten bolts hand-tight.
– Renew union on high-pressure pump.
– Now tighten bolts diagonally to required torque.
– Tighten union nut on fuel supply pipe hand-tight, »align stress-

free« and then tighten.

– Re-connect electrical connector -2- for fuel pressure regulat‐

ing valve - N276- .

– Put back fuse if it has been removed.
– Install air filter housing

⇒ page 467

– Start engine and check fuel system for leaks.
– Fit engine cover panel

⇒ page 141

Rep. gr.24 - Mixture preparation - injection

Checking components

Checking fuel pressure sender - G247-

⇒ page 493

Checking intake manifold change-over

⇒ page 496

3.1

Checking fuel pressure sender - G247-

Special tools and workshop

equipment required

♦ Assembly tool - T10118-
♦ Double hexagon socket, 27mm - VAS 5301/7-

493

♦ Pressure sensor tester - VAS 6394/1-
♦ Adapter - VAS 6394/2-
♦ Adapter - VAS 6394/4- (only Tiguan)
♦ Test adapter - VAS 5570-
♦ Torque wrench - V.A.G 1331-
♦ Vehicle diagnostic tester
♦ Vehicles with sound generator: Engine bung set - VAS 6122-
Procedure:
– Remove engine cover panel

⇒ page 141

– Remove fuel pressure sender - G247-

⇒ page 486

Vehicles with sound generator:
– Seal charge air duct connection to sound generator with plug

from engine bung set - VAS 6122- and secure plug with a hose

clip.

Continued for all vehicles:

Note

For the Tiguan, use adapter - VAS 6394/4- instead of adapter -

VAS 6394/2- .

– Moisten tapered seal of adapter - VAS 6394/2- with clean en‐

gine oil and screw into fuel rail. Specified torque: 27 Nm.

– Unscrew plug -2- and screw fuel pressure sender - G247- into

tester - VAS 6394/1- . Specified torque: 27 Nm.

– Connect pressure line of tester - VAS 6394/1- to adapter - VAS

6394/2- .

Rep. gr.24 - Mixture preparation - injection

– Switch on tester - VAS 6394/1- to do this, press button -A- once

briefly.

Note

♦

When button -A- is pressed for 2 seconds, the illumination will

be switched on for 20 seconds.

♦

If the digital pressure gauge - VAS 6394/1- reading is not 0

bar, perform zero calibration procedure ⇒ operating instruc‐

tions .

– Connect vehicle diagnostic tester to diagnostic connection.
– Switch ignition on.
– Press following buttons on display of diagnostic tester one af‐

ter the other:

Vehicle self-diagnosis

Self-diagnosis

►

01 - Engine electronics

►

011 - Measured values

►

– Select measured value block

and confirm with

The actual fuel pressure value is shown in display zone 3, meas‐

ured by the fuel pressure sender - G247- .
– Start engine.
– Compare the displayed pressure of pressure tester - VAS

6394/1- with the displayed actual value on vehicle diagnostic

tester .

• A maximum pressure deviation of 5 bar is permissible.
– If the deviation is greater than 5 bar, renew fuel pressure

sender - G247- .

WARNING

The fuel system is pressurised.
Danger of injury caused by fuel spray.

♦ Wear protective goggles.
♦ Wear protective gloves.
♦ To release pressure, wrap a clean cloth around the con‐

nection and carefully loosen the connection.

– Repeat the test with the new fuel pressure sender - G247- and

compare both measured values.

If measured values again fail to correspond:
– Check wiring ⇒ Vehicle diagnostic tester.

3.2

Checking intake manifold change-over

Perform check only if there is a loss of torque. This means when

there is a lack of elasticity or a lack of pulling power.
Special tools and workshop equipment required

Rep. gr.24 - Mixture preparation - injection

♦ Hand operated vacuum pump - VAS 6213-

Prerequisites for check
♦ The variable intake manifold valve - N316- was checked with

a vehicle diagnostic tester .

If the intake manifold flap valve - N316- is OK, perform the fol‐

lowing tests:
– Pull engine cover panel off carefully.
– Start engine and run it at idling speed.
– Have second person abruptly increase engine speed (throttle

burst). Observe vacuum unit for intake manifold change-over.

• The actuator must move -arrow-
If changeover does not operate as indicated:
– Check vacuum system for leaks.
– Check mechanical change-over components for ease of

movement. To do this, operate rods by hand.

– Check that vacuum lines are connected correctly.
– Check vacuum hoses for porosity.

– Remove vacuum hose -1- leading to actuator for intake mani‐

fold flap valve - N316- from intake manifold flap valve - N316-

-2-.

497

Engine control unit - J623- (Passat,

CC up to 11/10)

Removing and installing engine control unit

⇒ page 499

Removing and installing engine control unit with protective hous‐

ing

⇒ page 500

4.1

Removing and installing engine control

unit

Note

Removing and installing engine control unit with protective hous‐

ing

⇒ page 500

– If you wish to renew the engine control unit, connect the vehi‐

cle diagnostic tester and perform the guided function “Renew‐

ing engine control unit”.

Removing engine control unit
– Switch off ignition.
– Remove wiper arms ⇒ Electrical system; Rep. gr. 92 ; Wind‐

screen wiper system; Removing and installing wiper arms .

– Remove right plenum chamber cover ⇒ General body repairs,

exterior; Rep. gr. 64 ; Flush-bonded windows; Assembly over‐

view - plenum chamber cover .

– Pull connector -1- off heated windscreen control unit - J505- .
– Slide connector locking devices -2- on engine control unit out‐

wards and pull off both connectors.

– Remove securing bolts -3-.
– Remove retainer frame with engine control unit from plenum

chamber.

– Press locking device -1- outwards and slide engine control unit

-2- out in -direction of arrow-.

Installing engine control unit

499

– Slide engine control unit -1- into retaining frame in

-direction of arrow-.

– Fit retainer frame with engine control unit onto retainer -4-.

Specified torque of securing nuts for retainer -4-: 6 Nm.

– Tighten securing bolts -3- to 7 Nm.
– Fit connectors to engine control unit and slide locking devices

-2- inwards.

– Fit connector -1- to heated windscreen control unit - J505- .
– Install right plenum chamber cover ⇒ General body repairs,

exterior; Rep. gr. 64 ; Flush-bonded windows; Assembly over‐

view - plenum chamber cover .

– Install wiper arms ⇒ Electrical system; Rep. gr. 92 ; Wind‐

screen wiper system; Removing and installing wiper arms.

4.2

Removing and installing engine control

unit with protective housing

Special tools and workshop equipment required
♦ Grip pliers
– If you wish to renew the engine control unit, connect the vehi‐

cle diagnostic tester and perform the guided function “Renew‐

ing engine control unit”.

Removing:
– Switch off ignition.
– Remove wiper arms ⇒ Electrical system; Rep. gr. 92 ; Wind‐

screen wiper system; Removing and installing wiper arms .

– Remove plenum chamber cover ⇒ General body repairs, ex‐

terior; Rep. gr. 64 ; Flush-bonded windows; Assembly over‐

view - plenum chamber cover .

– Unscrew bolts -1-.
– Remove engine control unit cover, if fitted.
– Cover the plenum chamber with a clean cloth so that it is not

scratched.

– Raise engine control unit with retaining frame slightly.
– Release engine control unit -arrows- and pull out slightly.

Rep. gr.24 - Mixture preparation - injection

– Bend the upper ends -1- of locking clip outwards.
– Remove shear-head bolts -2- using grip pliers and remove

locking clip.

– Slide connector locking devices -1- on engine control unit out‐

wards and pull off both connectors.

– Remove engine control unit.
Installing:

– Slide engine control unit -1- in direction of -arrow- in retaining

frame until it engages.

– Tighten the retaining frame.

Specified torque: 6 Nm

– Fit connectors to engine control unit and slide locking devices

-1- inwards.

– Take a new locking clip and tighten new shear-head bolts

evenly until heads shear off.

– Install plenum chamber cover ⇒ General body repairs, exte‐

rior; Rep. gr. 64 ; Flush-bonded windows; Assembly overview

- plenum chamber cover .

– Install wiper arms ⇒ Electrical system; Rep. gr. 92 ; Wind‐

screen wiper system; Removing and installing wiper arms.

501

Engine control unit - J623- (Golf, Eos

to 11/08)

Removing and installing engine control unit

⇒ page 502

Removing and installing engine control unit with protective hous‐

ing

⇒ page 502

5.1

Removing and installing engine control

unit

Note

If you wish to renew the engine control unit, connect the vehicle

diagnostic tester and perform the guided function “Renewing en‐

gine control unit”.

Removing
– Switch off ignition.
– Remove windscreen wiper arms, plenum chamber cover and

plenum chamber bulkhead ⇒ Electrical system; Rep. gr. 92 ;

Windscreen wiper system; Removing and installing wiper

arms .

– Release front connector -1- from engine control unit and pull

it off.

– Lever up catch -2- slightly.
– Then push engine control unit out of retainer -arrow-.
– Then release rear connector on engine control unit and pull it

off.

Installing
– Fit rear connector to engine control unit and lock in position.
– Push engine control unit onto bracket.
– Fit front connector to engine control unit and lock it in position.
– Install plenum chamber bulkhead, plenum chamber cover and

wiper arms ⇒ Electrical system; Rep. gr. 92 ; Windscreen

wiper system; Removing and installing wiper arms .

5.2

Removing and installing engine control

unit with protective housing

Special tools and workshop equipment required
♦ Electric cutter - V.A.G 1561 A-
♦ Saw set - V.A.G 1561/14-

Rep. gr.24 - Mixture preparation - injection

♦ Grip pliers

♦ Hot air blower from wiring harness repair set - VAS 1978 B-

Note

If you wish to renew the engine control unit, connect the vehicle

diagnostic tester and perform the guided function “Renewing en‐

gine control unit”.

Removing:
– Switch off ignition.
– Remove windscreen wiper arms, plenum chamber cover and

plenum chamber bulkhead ⇒ Electrical system; Rep. gr. 92 ;

Windscreen wiper system; Removing and installing wiper

arms .

Note

The shear-head bolt threads are coated with locking compound.

Heating the shear-head bolt with a hot air blower releases the

locking effect of the locking compound.

Caution

Cover lines, connections and control units in the vicinity of the

engine control unit to prevent damage through heat.

Perform settings on hot air blower -4- as shown:

503

– Turn temperature setting potentiometer -2- to maximum heat

output (600°C).

– Set two-stage switch for volume of air -3- to position 3.

WARNING

When shear-head bolts are heated up, parts of the protective

housing will be subjected to a large amount of heat. Wear pro‐

tective gloves to avoid possible injury.

– Place nozzle of hot air blower close to shear-head bolt.
– Switch on hot air blower and heat the bolts.
– Remove bolts with grip pliers .

Note

If the bolts will not move, saw into heads of shear-head bolts so

that two parallel slots are created -arrows- and then remove the

bolts.

– Insert a screwdriver between protective housing -A- and

bracket -arrow-.

– Lever up protective housing using screwdriver -A- and pull to

side off bracket -arrow-.

Rep. gr.24 - Mixture preparation - injection

Volkswagen 4-cyl. injection engine (1.8 and 2.0 l engine, chain drive). Manual (Edition 08.2018) - page 16