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Checking variable intake manifold flap change-over valve N239 > < Checking injection timing device control range

Polo Mk3

Checking intake manifold flap change-over
Checking intake manifold flap change-over
Function
At low engine speeds the depression in the intake manifold is insufficient to guarantee a perfect function of the exhaust gas recirculation system. After starting the engine, the throttle valve is therefore closed up to an engine speed of approx. 2200 rpm to increase the vacuum.
Special tools and workshop equipment required
   
t  Hand vacuum pump with accessories -V.A.G 1390/-
  W00-0515
t  Spring-type clip pliers -VAS 5024 A-
Checking function
–  Remove air filter/inlet connection connecting hose from inlet connection.
–  Start engine and run at idling speed.
–  Observe position of intake manifold flap (2nd person required). Intake manifold flap must close approx. 3 seconds after starting engine.
–  Switch off ignition. Intake manifold flap must open after switching off ignition.
If change-over does not take place as described:
  W00-0495
–  Connect hand vacuum pump with accessories -V.A.G 1390/- to intake manifold flap vacuum unit -1-.
–  Operate hand vacuum pump with accessories -V.A.G 1390/-. Intake manifold flap must close to stop and remain closed.
If the specification is not achieved:
–  Check intake manifold flap change-over mechanics for freedom of movement. To do this, operate intake manifold flap by hand.
–  Check that vacuum lines are connected correctly.
If a fault is found in the mechanical components:
–  Renew inlet connection → Chapter, Removing and installing inlet connection.
If no fault is found in the mechanical components:
–  Check variable intake manifold flap change-over valve -N239- → Chapter.
  N23-0215

Checking variable intake manifold flap change-over valve N239 > < Checking injection timing device control range