Ignition Timing: Adjustments

With transmission in Park, start and warm engine to normal operating temperature. Turn Off A/C and all accessories. Connect tachometer to engine and timing light to No. 1 spark plug wire.
With engine running, ground the ALDL test connector (located under the driver's side dash). Loosen the distributor hold-down bolt and set timing to specifications. Tighten the distributor housing and recheck the timing. With engine still running, disconnect jumper from ALDL test connector. If jumper wire is removed before engine is shut off, no trouble code will be store.