V6 Ignition Timing

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 Malfunction Indicator Light (MIL) is off.
NOTE: The location of the EST by-pass connector has been updated per General Motors Service Manual Update number 41-65-41, dated January 4, 1995.
Disconnect Tan/Black Electronic Spark Timing (EST) by-pass connector wire. DO NOT disconnect 4-wire connector at distributor.
On models where engine computer is located underhood, on right fenderwell, by-pass connector which is a single Tan/Black wire, breaks out of wiring harness near engine computer harness connectors.
On models where engine computer is located in passenger compartment under right side of instrument panel, by-pass connector which is a single Tan/Black wire and breaks out of wiring harness where heater box and carpet meet on passenger side floor. Pull back carpet to expose single Tan/Black wire and connector on outside of control module harness.
On all models, connect timing light to No. 1 spark plug wire. Check timing and adjust if necessary. See V6 IGNITION TIMING table. Reconnect EST by-pass connector, and clear ECM trouble code.

V6 IGNITION TIMING (DEGREES BTDC @ RPM)

Application	Man. Trans.	Auto. Trans.
4.3L (VIN W & Z)	0 @ Idle	0 @ Idle