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Idle Speed & Mixture

NOTE: Mixture adjustment is NOT a part of normal tune-up procedure and should not be performed unless injection system components are being replaced or vehicle fails emissions testing.
  1. Warm engine to operating temperature (electric fan has cycled twice). Place manual transmission in neutral or automatic in "D". Wait until electric fan is off to adjust idle.
    Fig 1: Fuel Injection Idle Speed Adjustment
    G09314242Courtesy of NOT AVAILABLE
  2. Turn air bypass screw on top of intake manifold to adjust idle speed. See  Fig 1 . 
  3. Connect CO meter to pipe tap in front of catalytic converter. Disconnect plug from oxygen sensor and ensure that neither side is grounded. Remove plug from air flow meter and adjust CO%. See  Fig 2 . 
  4. Ground control unit side of oxygen sensor connector. CO level should rise to at least 1.5%. Reconnect oxygen sensor and check for CO level of 0.3-0.6%. Remove test equipment and plug air flow meter screw. See  Fig 2 . 
    Fig 2: Fuel Injection Mixture Adjustment
    G09314243Courtesy of NOT AVAILABLE
    IDLE SPEED & CO LEVEL

    Application Idle RPM CO%
    All Models
      Man. Trans 800-900 0.5-0.9
      Auto. Trans (1) 700-800 0.5-0.9
    (1) Transmission in "D".
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