All Models (Except Diesel)

Set parking brake, block drive wheels and place transmission in Neutral or Park. Warm engine to normal operating temperature. Turn A/C off (if equipped). Ensure SERVICE ENGINE SOON light is not on.
Disconnect Tan/Black Electronic Spark Timing (EST) by-pass connector wire located near distributor. DO NOT disconnect 4-wire connector at distributor.
Connect timing light to No. 1 spark plug wire. Check timing and adjust if necessary. See V8 IGNITION TIMING . Reconnect EST by-pass connector, and clear ECM trouble code.

V8 IGNITION TIMING (DEGREES BTDC @ RPM)