volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Checking functions > < Checking fuel pressure regulator and holding pressure
Motronic injection and ignition system (4-cyl. engine)
Checking components
Checking intake air system for leaks (unmetered air)

Checking with engine leak detector spray G 001 800 A1

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

  • ◆ Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3
  • ◆ Engine leak detector spray G 001 800 A1

Test conditions

  • ● Coolant temperature must be at least 85 °C, =>display group 04, display zone 3.

Test sequence

Notes:

  • ◆ The vacuum in the intake system will cause the leak detector spray to be drawn in with the unmetered air. The leak detector spray reduces the ignitability of the mixture. This leads to a drop in engine speed and to a change of Lambda probe reading.
  • ◆ The safety precautions listed on the container must be adhered to.
  • ‒ Connect fault reader V.A.G 1551 (V.A.G 1552). Start engine and select "Address word" 01 of engine control unit. When doing this the engine must be running at idling speed.
    (Connecting fault reader and selecting engine control unit .)
 
→ Indicated on display:
Rapid data transfer     HELP
Select function XX
  • ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.
 
→ Indicated on display:
Read measured value block     HELP
Input display group number XXX
  • ‒ Press keys 0, 0 and 1 for "Display group number 1" and confirm entry with Q key.
 
→ Indicated on display:
(1...4 = Display zones)
Read measured value block 1     ⇒
     1     2     3     4
  • ‒ Observe the engine speed in display zone 1 and the Lambda regulation in display zone 3.
  • ‒ Systematically spray parts of the intake system with engine leak detector spray.

If the engine speed drops or the Lambda regulator changes:

  • ‒ Press ⇒key.
  • ‒ Press keys 0 and 6 for the "End data transfer" function and confirm input with the Q key.
  • ‒ Switch off ignition.
  • ‒ Check sprayed areas of intake system for leaks and rectify if necessary.

Checking functions > < Checking fuel pressure regulator and holding pressure