Intake-Air System Manifold Vacuum Inspection

WARNING: This page is about a different car, the 2004 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

Verify that the intake-air system related parts and hoses are securely installed.
Remove the intake manifold blind cap and install the vacuum gauge.
Warm up the engine.
Measure intake manifold vacuum while no load and idling.

Fig 1: Inspecting Intake-Air System Manifold Vacuum
Courtesy of MAZDA MOTORS CORP.

Intake manifold vacuum

MT: -66.7-56.0 kPa {-500.2-420.1 mmHg, -19.6-16.6 inHg

AT: -67.3-53.4 kPa {-504.7-400.6 mmHg, -19.8-15.8 inHg
- If not within the specification, perform the following inspection:
- Compression pressure (See COMPRESSION INSPECTION .)
- Air intake
  - Each hose installation part
  - Throttle body installation part
  - Fuel injector installation parts
  - Extension manifold (upper, lower) installation part
  - Purge solenoid valve installation part
  - Intake manifold installation part