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Home >> Mercury >> 1977 >> Capri II Base, 2.3L Eng, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> DECEL Valve System >> Adjustment >> Conventional DECEL Valve
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Conventional DECEL Valve

  1. Run engine at 1200 RPM for 20 minutes. Connect tachometer. Remove air/fuel mixture hose from decel valve and connect a vacuum gauge, using a "T" fitting, so valve remains operational.
  2. With transmission in Neutral, raise engine speed to 3000 RPM. Hold RPM steady for 5 seconds, release throttle, and note time required until vacuum gauge reads zero (0).
  3. Correct decel valve timing should be 2-5 seconds. If not, use Driver (T73P-9K809-A) to turn nylon adjuster clockwise to decrease time or counterclockwise to increase time.
  4. After adjustment of decel valve, check that fast idle speed is to specification. If valve timing cannot be adjusted, replace valve.
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