V6 Ignition Timing: 4.3L
- Warm engine to normal operating temperature. Disconnect Electronic Spark Timing (EST) by-pass connector, located on wiring harness on right front side of engine, near AIR control valve.
- Connect timing light to spark plug No. 1 wire. Loosen distributor hold-down bolt. Set timing to zero degrees BTDC at idle with transmission in Drive. Tighten distributor hold-down bolt, and recheck timing.
- Turn engine off. Reconnect EST by-pass connector. Clear ECM code by disconnecting battery negative terminal for at least 30 seconds.