audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

Removing and installing fuel manifold with injectors and throttle valve unit > < Checking system pressure, fuel pressure regulator and holding pressure
MPFI Fuel Injection and Ignition System
Repairing Multi Point Fuel Injection system
Checking injectors
 
G24-0018

Special tools and workshop equipment required

  • ◆ V.A.G 1526 A
  • ◆ V.A.G 1527 B
  • ◆ V.A.G 1594 A
  • ◆ V.A.G 1598 A
  • ◆ V.A.G 1598/12
  • ◆ VAS 5051 with VAS 5051/1
  • or
  • ◆ V.A.G 1551 with V.A.G 1551/3 A

Checking internal resistance

  • ‒ Unplug connector on injector to be checked.
 
V96-0848
  • ‒ → Connect multimeter to valve to measure resistance
    • ‒ Specification: 13.5 ... 17 ω

If the specification is not obtained:

  • ‒ Replace injector.

Checking power supply

Test requirements:

  • ● Fuel pump relay OK; checking .
 
A97-0022
  • ● → Fuse S234 OK (in fuse holder, position 34).
  • ‒ Unplug connector on injector to be checked.
 
V96-0749
  • ‒ → Connect voltage tester V.A.G 1527 B as follows:

Connector
Contact

Measure to

1

Engine earth

  • ‒ Operate the starter briefly (the engine may start).
    • ‒ The LED should light up.

If the LED does not light up:

  • ‒ Check wiring from contact 1 via fuse S234 (in fuse holder, position 34) to fuel pump relay:

=> "Current Flow Diagrams, Electrical Fault Finding and Fitting Locations" binder

Checking actuation

  • ‒ Unplug connector on injector to be checked.
 
V96-0749
  • ‒ → Connect voltage tester V.A.G 1527 B as follows:

Connector
Contact

Measure to

2

Battery positive

  • ‒ Operate the starter briefly (the engine may start).
    • ‒ The LED should flash.

If LED does not flash:

  • ‒ Check the wiring
    .

If the LED does not flash for any of the injectors:

  • ‒ Check the power supply to the engine control unit => page 28-37.

Checking wiring

  • ‒ Unplug connector on injector to be checked.
 
A87-0016
  • ‒ → With the ignition switched off, use adapter V.A.G 1598/12 to connect test box V.A.G 1598 A to connector D only of engine control unit (control unit remains disconnected) => Page 24-9.
 
V96-0749
  • ‒ → Check for open circuit and short to earth/positive or earth in the following wiring connections:

Cylinder

Injector connector
Contact

Test box V.A.G 1598 A
Socket

1

2

6

2

2

7

3

2

8

4

2

13

5

2

14

6

2

15

  • ‒ Rectify any open/short circuit as necessary.

=> "Current Flow Diagrams, Electrical Fault Finding and Fitting Locations" binder

Removing and installing fuel manifold with injectors and throttle valve unit > < Checking system pressure, fuel pressure regulator and holding pressure