Variable Induction System: Testing and Inspection

Variable Intake Manifold, Checking

Only perform the test if there is a loss of torque. That means engine acceleration is reduced.

Special tools, testers and auxiliary items 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 tests:

- 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.

• 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".






- Connect the hand vacuum pump (VAS 6213) to the intake manifold runner control valve actuator.






- Operate the hand vacuum pump (VAS 6213) several times.

The vacuum actuator must move - arrows -.

- Replace the vacuum actuator if it does not move.