Firing Orders
NOTE: To avoid confusion, remove and tag the spark plug wires one at a time, for replacement.
If a distributor is not keyed for installation with only one orientation, it could have been removed and installed improperly and then rewired. The new wiring arrangement would maintain the correct firing order, but could change the relative placement of the plug towers in relation to the engine. For this reason it is imperative that you label all wires before disconnecting any of them. Also, before removal, compare the current wiring with the accompanying illustrations. If the current wiring does not match, make notes of the current plug wire locations and orientation of the distributor cap.
3.9L Engine
1-6-5-4-3-2
5.2L Engine
1-8-4-3-6-5-7-2
5.9L Engine
Firing order: 1-8-4-3-6-5-7-2
4.7L Engine
Firing order: 1-8-4-3-6-5-7-2
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