Contents: Examination ↓ Replacement ↓
The intake channel selection system switches the air supply channel depending on the engine load. The system drive is controlled by the vacuum in the intake manifold.
Vacuum lines ACIS-system
1. Idle air bypass valve; 2. From the air filter; 3. Vacuum chamber; 4. Pneumatic distributor; 5. Drive
Examination
1. Install a tee with a vacuum gauge between the drive and the vacuum hose. Start the engine. There should be no vacuum at idle. When you press the accelerator pedal sharply, the vacuum should be 200 mm Hg, and the drive rod should retract.
2. If there is no vacuum, check the cleanliness of the fitting and the serviceability of the hoses and pneumatic distributor
3. Check the vacuum chamber and the pneumatic distributor. When purging the chamber, air should only flow from port B to port A.
4. When creating a vacuum in connection A, air should not pass through connection B for 1 min.
5. The resistance of the air distributor coil should be 33–39 Ohms at 20°C.
5. Replace the air distributor if the coil resistance is not within the normal range.
Replacement
1. Disconnect the battery from ground, disconnect the vacuum hoses from the brake booster, fast idle valve and air bypass valve.
2. Loosen the bypass valve bolts and remove the bypass valve assembly with the drive.