Only perform the test if there is a loss of torque. That means engine acceleration is reduced.
Special tools and workshop equipment required
- Hand Vacuum Pump -VAS 6213
Test Conditions
- The intake manifold runner control valve -N316- was tested using the vehicle diagnostic tester.
If the intake manifold runner control valve is OK, perform the following
Remove the engine cover carefully.
Start the engine and let run at idle.
Have a 2nd person increase the engine speed abruptly (press the accelerator pedal). Observe the variable intake manifold vacuum actuator.
Scheme 23
- The actuator must activate -arrow-.
If the change over does not function as specified
Check the vacuum system for leaks.
Check whether the change over mechanism moves easily. Do this by actuating the linkage by hand.
Check whether the vacuum lines are correctly connected.
Check that vacuum hoses are not porous.
Remove the adjusting element vacuum hose -1- for the intake manifold runner control valve from the valve -2-.
Set the sliding ring -1- on the hand vacuum pump -VAS 6213- to the -A- position for "vacuum".
Scheme 24
Connect the hand vacuum pump -VAS 6213- to the intake manifold runner control valve actuator.
Scheme 25
Operate the hand vacuum pump -VAS 6213- several times.
The vacuum actuator must move -arrows-.
Replace the vacuum actuator if it does not move.