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Checking valve for commencement of injection > < Testing injection control

A4 Mk1

TDI Injection and Glow Plug System (4-cyl.) 07.97 > 07.99
Testing injection control
Checking the injection timing control range
  • ‒ Start the final control diagnosis and activate the valve for the commencement of injection. .
 
→ Indicated on display:
Final control diagnosis    ⇒
Injection start valve N108
  • Valve actuation has a considerable effect on combustion noise (pre ignition).
  • ‒ Initiate the basic setting, display group 00 => Page 01-46.
 
→ Display readout (for example):
System in basic setting 0    ⇒
42    46    0    20    90    201    64    153    127    83
  • ‒ If necessary, correct injection start
    .
  • ‒ Remove fuse for the engine electronics from the electronics box.
  • ‒ Observe display in display zone 2.
 
→ The display should run up to 255.
Basic setting 0    ⇒
42    255    0    20    90    201    64    153    127    83

Note:

The interruption to the power supply will cause the valve for the commencement of injection to close. The interior pressure in the pump cannot be reduced further, and therefore the full pressure is applied to the injection timing control piston. This moves the injection timing control to the "advanced" stop.

If specified value is not attained:

  • ‒ Replace the injection pump.
  • ‒ Interrogate and delete fault memory => Page 01-8.

Checking valve for commencement of injection > < Testing injection control