WE have had several issues with misfires and have replaced several coil packs and plugs multiple times. Always seems to misfire only in early morning until it warms up or in damp wet conditions. We have a 2005 F150
Country: United StatesMake: FordModel: F150Year: 2005Engine: 4.2 Litre
Actually just checked recordsand it has always been either #1 or #5 cylinder misfire. These both go to same coil pack. Have changed coil pack twice in 10,000 miles and plugs as well. All wires were changed recently. Runs ok for awhile then misses again. Wondered if Ford has any coil Pack issues for this model
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You need to check the signal wire to the coil for cyl 1 and 5. Check for a pulse with a noid light. Only check when you have it at a misfire. If it is not misfiring when you check it then it will test ok. If no pulse then the computer is faulty and needs to be replaced.
Thanks Steve. We will try that next time I guess. Seems to be ok at the moment after changing plugs and coil pack. Just an ongoing issue with these two cylinders over one year period.
I would strongly suspect the pcm is going bad.
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25 years working for Ford dealer. Ford Master tech.