What makes a misfire on the # 8 Cyclinder after changing the coil,spark plug and the booth on my 2001crown victoria with a 4.6 engine?
Bad new plug, damaged plug, coil out of specs, too much dielectric grease on plug boot during replacement, damaged coil wiring.
If the miss wasn't there before you changed plugs my bet is you purchased a coil from an autoparts store that wasn't Ford - Motorcraft. The cheap coils sometimes don't work very well. If the miss was there before, try swapping the fuel injector with another cylinder to see if the miss moves with the injector.
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