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Home >> Honda >> 1989 >> Prelude S, Standard >> Repair and Diagnosis >> Engine Performance >> System >> System/Component Tests - CARBURETED >> Emission Systems & Sub-Systems >> Purge Control System >> Purge Control Diaphragm Valve
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Purge Control Diaphragm Valve

  1. With engine coolant temperature less than 145°F (63°C), disconnect the No. 19 vacuum hose at purge control diaphragm valve and connect vacuum gauge to hose. See Fig 1. Start engine and allow to idle. Vacuum should not be present. If not, go to next step. If so, test purge cut-off solenoid valve.
  2. Start engine and warm to normal operating temperature (cooling fan comes on). Block rear wheels and set parking brake. Jack up front of vehicle and support with safety stands. Place selector lever in the "2" position or 2nd gear and raise engine speed to 3500 RPM. Vacuum should be present. If so, valve is okay. If not, test purge cut-off solenoid valve.
    Fig 1: Testing Purge Control Diaphragm Valve
    G117946Courtesy of AMERICAN HONDA MOTOR CO., INC.