LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Plymouth >> 1978 >> Arrow Base, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Jet Air System >> Adjustments >> Jet Valve
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Jet Valve

  1. Before performing jet valve adjustment, cylinder head bolts must be retightened (cold) to 65-72 ft. lbs. (88-98 N.m). After engine is at normal operating temperature, stop engine, remove rocker cover, and position appropriate piston at TDC.
  2. Fig 1: Mixture Control Valve System (1977)
    G09313047Courtesy of CHRYSLER GROUP, LLC
  3. Back off intake valve side adjusting screw 2 or more turns. Jet valve clearance should be adjusted with intake valve adjusting screw fully loosened. 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. See Fig 2.
  5. Turn down adjusting screw (clockwise) until proper clearance is obtained. Hold adjusting screw and tighten lock nut. Recheck clearance. Adjust intake valve clearance to 0.006" (0.15 mm). Repeat adjustment at each cylinder.
    Fig 2: Adjusting Jet Valve Clearance
    G09313048Courtesy of CHRYSLER GROUP, LLC