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Home >> Acura >> 1991 >> Legend Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Emission Systems & Sub-Systems >> Evaporative Emission Controls >> 2-Way Valve
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2-Way Valve

  1. Remove fuel filler cap. See Fig 1 . Remove vapor hose from fuel tank side of 2-way valve, and install "T" fitting. Connect vacuum gauge to "T" fitting and vacuum pump to hose end.
  2. Slowly apply vacuum while watching vacuum gauge. Vacuum reading should stabilize momentarily between .2-.6 in. Hg. If vacuum does not stabilize (valve opens) in specified range, replace 2-way valve, and retest.
  3. Move vacuum hose from vacuum to pressure fitting side of vacuum pump. Slowly pressurize vapor line while watching gauge. If pressure stabilizes between .4-1.4 in. Hg, valve is okay. If pressure does not stabilize in specified range, replace 2-way valve, and retest.
    Fig 1: Identifying Evaporative Emission Control System
    G120091Courtesy of AMERICAN HONDA MOTOR CO., INC.