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Home >> Mazda >> 2021 >> MX-5 Miata Club, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine Control >> Engine Control System Operation Inspection >> Intake Manifold Vacuum Inspection

Intake Manifold Vacuum Inspection

  1. Disconnect the evaporative hose between the intake manifold and purge solenoid valve from the intake manifold side.
  2. Connect a vacuum gauge to the intake manifold.
  3. Verify the air intake hoses are installed properly.
  4. Start the engine and let it idle.
  5. Measure the intake manifold vacuum.
    • If not within specification, inspect the following:

    Specification

    -60.0 kPa {-450 mmHg, -17.7 inHg}

    NOTE:
    • Air suction can be located by the engine speed change when lubricant is sprayed on the area where suction is occurring. Check the following places:
    • Air suction at throttle body, evaporative hose, vacuum hose, ventilation hose, check valve (built-into vacuum hose), fuel injector, intake manifold and PCV valve installation points