Ignition Timing: Adjustments
Set timing at slow idle and Before Top Dead Center, unless otherwise specified.
2.5L (151), ground diagnostic connector under dash. Average pulses of cylinders 1 & 4.
2.8L (173) FI, place system in bypass mode, disconnect tan/black wire by ECM in passenger compartment.
2.8L (173) 2V EST, disconnect 4-wire connector at distributor.
4.3L (262) FI, place system in bypass mode, disconnect tan/black wire at distributor.
All V8 W/FI, place system in bypass mode, disconnect tan/black wire inboard of bulkhead.
All others, disconnect & plug distributor vacuum hoses(s).