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Home >> Mercury >> 1972 >> Capri 2.0L Eng VIN X, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> 1973 CAPRI DECEL Valve >> Service Procedures
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Service Procedures

Connect a tachometer and install a vacuum gauge between carburetor and decel valve. Length of tube connecting vacuum gauge should not exceed 60". With engine at normal operating temperature, ignition timing and idle RPM set to specifications, proceed as follows:

  1. Bring engine to 3000 RPM and maintain for about 2 seconds. Release throttle and note time interval between throttle release and a zero reading on the vacuum gauge. Time interval should be as follows:
    Engine Seconds
    2000 cc (Man. Trans.) 2.5-3.5
    2000 cc (Auto. Trans.) 1.5-3.5
    2600 cc (All) 1.5-3.5
  2. If adjustment required, remove and discard colored cap (if equipped) for access to nylon adjuster. Using a suitable tool, back adjuster outward to increase time or turn adjuster inward to increase time. One turn of adjuster, in either direction, will increase or decrease time approximately 1/2 second.
  3. When nylon adjuster is flush with top of threaded collar, the maximum permissible adjustment is 1 full turn inward or 9 turns outward. When adjustments are completed, snap in new service replacement colored cap in top of valve.
    Fig 1: CAPRI DECEL VALVE
    G09354980Courtesy of FORD MOTOR CO.