Variable Induction System: Testing and Inspection

Variable Intake Manifold, Checking

Only perform test if there is a loss of torque. That means elasticity or engine torque is reduced.

Special tools, testers and auxiliary items required
- Hand vacuum pump VAS 6213

Test Conditions
- The Intake manifold runner control valve N316 was installed with Vehicle diagnosis, testing and information system VAS 5052.

If Intake manifold runner control valve N316 is OK, perform the following tests:
- Remove engine cover carefully.
- Start engine and let run at idle.
- Have a 2nd person increase engine speed abruptly (press accelerator pedal). Observe variable intake manifold vacuum actuator.







- The actuator must activate - arrow -.

If change over does not function as specified:
- Check vacuum system for leaks.
- Check whether change over mechanism moves easily. Do this by actuating linkage by hand.
- Check whether vacuum lines are correctly connected.
- Make sure vacuum hoses are not porous.







- Remove vacuum hose - 1 - on intake manifold runner control valve N316 - 2 - to control valve actuator.







- Set slide ring - 1 - on hand vacuum pump VAS 6213 to - A - position for "vacuum".







- Connect hand vacuum pump VAS 6213 to Intake manifold runner control valve N316 actuator.
- Operate hand vacuum pump VAS 6213 several times.

The vacuum actuator must move - arrows -.
- Replace vacuum actuator if it does not move.