IDLE MIXTURE SCREW ADJUSTMENT
- Bring the engine to operating temperature.
- Adjust the idle to manufactures specifications.
- NOTE: Having the idle up too high will bypass the idle circuit and adjusting the idle mixture will have not affect.
- Hook up a vacuum gauge to a port that has steady vacuum.
- Turn both screws out 1/2 turn - Turn the idle mixture screw out 1 1/2 turns while on the bench.
- Turn each screw in, alternating between them, 1/4 turn at a time until you get a steady vacuum reading.
Another option:
- Bring the engine to operation temperature.
- Adjust the idle to manufactures specifications.
- Turn both idle mixture screws out 1/2 turn.
- Alternating between the screw turn in 1/4 turn at a time. Give the engine a second to catch up.
- When the rpm starts to drop, turn the screw back 1/4 turn and leave it there.
1978 American Motors
- Loosen choke housing cover. Rotate 1/4 turn in RICH direction
1978 Chrysler Corp
- Place fast idle speed adjusting screw on SECOND HIGHEST step of fast idle cam. Apply light pressure on choke valve shaft lever to close choke valve
- Open throttle slightly. Place fast idle screw on second step of fast idle cam. Measure distance between choke valve and air horn wall
- Adjust by bending fast idle cam link (fast idle connecting rod) down to increase measurement or up to decrease measurement. Loosing housing cover screw, reset choke to correct index specificaiton and tighten all retaining screws
