volkswagen Workshop Repair Guides

Volkswagen Passat Workshop Service and Repair Manuals

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Basic throttle valve setting > < Checking intake air system for leaks (unmetered air)

Checking Intake Air Preheating for Passat (B3) - Digifant Injection and Ignition System

Digifant Injection and Ignition System
Digifant injection and ignition system
Checking intake air preheating

Checking regulating flap

  • ● Regulating flap vacuum unit not leaking
  • ‒ Loosen air cleaner upper part and remove filter element.
 
N24-0012
  • ‒ → Position air cleaner upper part so that the regulating flap in air cleaner lower part can be seen.
  • ‒ Pull vacuum pipe -3- off the temperature regulator vacuum unit.
  • ‒ Connect vacuum pipe to hand vacuum pump V.A.G 1390.
  • ‒ Operate pump and check ease of movement of the regulating flap and function of the vacuum unit.
         Regulating flap must close off the cold air
         intake -1-

Checking temperature regulator

  • ‒ Connect vacuum pipe to temperature regulator.
  • ‒ Start engine and run at idling speed.
 
N24-0012
  • ‒ → Check position of regulating flap after max. 20 seconds.

Temperature of temperature regulator

Regulating flap position

Below 20 °C

Cold air inlet -1- closed

Above 30 °C

Warm air inlet -2- closed

Between 20 and 30 °C

Between cold and warm air inlet

Basic throttle valve setting > < Checking intake air system for leaks (unmetered air)