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Variable Intake Manifold, Checking






Variable Intake Manifold, Checking

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

Special tools, testers and auxiliary items required

Hand Vacuum Pump (VAS 6213)

Test Conditions

The intake manifold runner control valve (N316) was checked with the vehicle diagnostic tester.

If the intake manifold runner control valve (N316) is OK, perform the following tests:

- Remove the engine cover.

- Start engine and let run at idle.

- Have a second person increase engine speed abruptly (press accelerator pedal). Observe the variable intake manifold vacuum actuator.

The actuator must activate - arrow -.






If 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.

- Disconnect the vacuum hose - 1 - on the Intake Manifold Runner Control (IMRC) valve 2 (N316) - 2 -.






- Set the slide ring - 1 - on the (VAS 6213) to the -A- position for "vacuum."






- Connect the (VAS 6213) to the IMRC valve actuator.






- Operate (VAS 6213) several times.

The vacuum actuator must move - arrows -.

- Replace the vacuum actuator if it does not move.