Idle Mixture Adjustment

Mixture Adjusting Screw Plug:

1. Remove concealment plugs as follows:

^ Remove air cleaner.
^ Remove vacuum hose from base of carburetor.
^ Remove carburetor from vehicle.
^ Mark the center of the plug with a punch.
^ Drill a hole in the plug with a drill and then thread a screw into the hole. Pull on the screw to remove the plug.
^ Reinstall carburetor on vehicle.

CAUTION: Drill depth should be no greater than 10 mm, because the plug is only 10 mm (0.39 in.) long and damage to the mixture screw could result.

2. Set parking brake and place transmission in neutral position.

3. Turn "OFF" all lights and accessories.

4. Connect a tachometer to the engine.

5. Start the engine and allow to warm up to normal operating temperature.

6. Turn engine "OFF."

7. LIGHTLY tighten the idle mixture until it seats. Back the idle mixture screw out the following number of turns:

^ Three turns from fully closed (Manual Transmission).
^ Two turns from fully closed (Automatic Transmission).

8. Check ignition timing, if it is incorrect go to IGNITION TIMING and adjust to specifications, if it is OK go to step 9.

9. Disconnect idle set electrical connector. The CHECK ENGINE lamp will come "ON."

10. Reinstall the air cleaner assembly, and make sure that the idle speed is correct. If the idle speed is not correct go to IDLE SPEED and adjust to specifications, if it is OK then go to step 11.

Carburetor Electrical Connector:

11. With the carburetor electrical connector still connected, attach the positive lead of a dwell meter to the RED duty monitor lead in pin number 3 of the carburetor electrical connector, and ground the negative lead.

12. Set the dwell meter dial to 6 cylinder, and adjust the idle mixture screw so that the meter reads 30° dwell.

13. Connect the idle set connector, the CHECK ENGINE lamp will go out.

14. Repeat steps 11 and 12 one time after the idle set connector has been reconnected.