1997 ford f 150 extended cab, v8
changed plugs, wires, coil pack, and fuel injector
check engine light still on
Cylinder 7 is still misfiring
Has it Ben over heated at all I? If so I would check the oil for water look for white smoke steam coming from exhaust pipes compression test may not be a bad idea as well
It could be carbon deposits on valve seats keeping valves from totally closing. You can try getting you a can of motorcraft PM3 top end engine cleaner and get engine up to operating temp then remove one of the small vacuum lines from the intake and draw the contents of the can slowly into the engine.After you have drawn in the contents shut engine off and let it soak for about 45 minutes then crank it back up and let it run until it clears. Now it will smoke like a forrest fire while you are doing this so don't be alarmed,just tell the neighbors you are spraying for mosqitos.This may cure the problem. If not you may be looking at a valve job.
This can be verified with a compression test if this is what is causing it.
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I have the same problem with my 97 Town Car. Changed all the same parts but still misses. The number 4 cylinder.
Check system light, bucking.
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