Fuel Delivery and Air Induction: Adjustments

1985-87 6-292 W/1ME & 1MEF CARBURETORS
A/C control, if equipped, must be in off position during adjustments. Perform adjustments with transmission in Neutral on all models.
1. Set parking brake, then block drive wheels.
2. Remove air cleaner for access to carburetor, but leave vacuum hoses connected. Disconnect and plug other hoses as directed on vehicle emission label.
3. Connect tachometer to engine following manufacturer's instructions, then start engine and allow to reach normal operating temperature.
4. Check and, if necessary, adjust ignition timing.
5. On 1ME carburetors, remove limiter cap from mixture adjusting screw, taking care not to damage screw.
6. On 1MEF carburetors, remove plug covering mixture screw as outlined under ``Concealment Plug Removal'' in the appropriate carburetor section.
7. On 1985 units, connect suitable vacuum gauge to carburetor port ``B'', then turn mixture screw until maximum vacuum reading is achieved at idle speed shown on vehicle emission label. On 1986-87 units, turn mixture adjusting screws to obtain highest idle RPM.
8. On 1985 units, remove vacuum gauge, then, on all units, check and adjust fast idle speed, if necessary.
9. Reconnect vacuum hoses, then check and adjust curb idle as required.