Audi Workshop Service and Repair Manuals

Note:

Defective injectors cause the following faults:

• ◆ Loss of power
• ◆ Excessive black exhaust smoke
• ◆ Excessive blue smoke when starting from cold
• ◆ High fuel consumption
• ◆ Engine overheating
• ◆ Knocking in one or more cylinders
• ◆ Misfiring

Removing

• ‒ Remove injection pipes using open ring spanner 3035.

Note:

Always complete remove pipe set. Do not alter pipe shape.

• ‒ Remove securing nut, take off retainer and take out injector.

If the injectors are seized, construct the following auxiliary tool:

• ‒ Saw off an injection pipe about 5 cm away from the injector union nut.
• ‒ Braze an M6 nut onto the sawn off end of the pipe section.
• ‒ Clean the auxiliary tool thoroughly. Any dirt will render the injector unusable.
• ‒ → Screw the union nut end of the auxiliary tool to the seized injector, then apply special tool 3364 to the end with the soldered-on nut.

Installing

Note:

Always renew copper seals between cylinder head and injectors.

• ‒ Insert the injectors.
• ‒ Check mounting bracket is seated correctly in the cylinder head.
• ‒ Fit retainer.

Tightening torque:

• Injection pipes: 25 Nm
• Retainer screw: 20 Nm

Checking

• Specified value: -1.50 mg/stroke +1.50 mg/stroke (milligrams per stroke)

• ‒ If one or more of the specified values is out of range, swap round the injectors (except the injector for No.3 cylinder).
• ‒ If the fault moves along with the injector, fit a new injector.
• ‒ If the fault remains on the cylinder, check the compression.
• ‒ If the compression is OK, renew the relevant pressure valve and sealing ring =>Repair injection pump - Page 23-8.

Notes:

• ◆ When removing the sealing ring from the pump, always use a soft object (plastic or wood) in order not to scratch the sealing surface.
• ◆ After 15,000 km, the complete set of pressure valves must always be replaced.

This engine is equipped with dual spring injectors. The fuel injection therefore takes place in 2 stages.
If faults occur in these injectors they must be replaced, since neither repair nor pressure setting is possible.

→ Testing injectors using V.A.G 1322 and pressure pipe V.A.G 1322/2.

• ● Pressure gauge on

• ‒ Slowly depress the pump lever. When injection begins, read off spray pressure. If the pressure does not match the specified value, fit a new injector.

Engine codes: AGR, AHF

Engine codes: ALH and ASV

Testing for leaks

• ● Pressure gauge on

• ‒ Move pump lever down slowly and maintain a pressure of approx. 150 bar for 10 seconds. No fuel should leak from the injector opening.
• ‒ If injector leaks, replace.