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Jet Valve Adjustment

  1. Before beginning adjustment, note the following:
    • Misadjusted jet valve clearance will adversely affect emission levels.
    • Adjust jet valve clearance before adjusting intake valve clearance.
    • Before adjusting jet valve, retighten cylinder head bolts (cold) to 51-54 ft. lbs. (7-7.5 mkg) on 1400 and 1600 cc engines or 65-72 ft. lbs. (9-10 mkg) on 2000 and 2600 cc engines.
    • Adjust jet valve clearance with intake valve adjusting screw fully loosened.
  2. With engine at normal operating temperature, stop engine, remove rocker cover and position appropriate piston at TDC of compression stroke.
  3. Back off intake valve side adjusting screw 2 or more turns. Loosen lock nut on jet valve adjusting screw.
  4. Back off jet valve adjusting screw (counterclockwise) and place 0.006" (0.15 mm) feeler gauge between top end of jet valve stem and bottom end of adjusting screw. Fig 2.
  5. Turn down adjusting screw (clockwise) until proper clearance is obtained.
    NOTE: Tensile strength of jet valve spring is weak. Use care during adjustment not to force screw to turn, putting excess pressure on spring.
  6. Hold adjusting screw and tighten lock nut. Recheck clearance. Adjust intake valve clearance to 0.006" (.15 mm). Repeat adjustment at each cylinder.
Fig 1: Cutaway View of Jet Air System
G09313820Courtesy of CHRYSLER GROUP, LLC
Fig 2: Adjusting Jet Valve Clearance
G09313821Courtesy of CHRYSLER GROUP, LLC