I would recommend finding someone who has access to FORD IDS to find this issue for your cylinder 8 misfire.
It can only be 3 things:
*Fuel Injector
*Coil/Bad Spark plug
*Cylinder Issue (Piston,Valve or cylinder)
Tests to run:
Misfire Test to confirm the cylinder
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Fuel injector Test (Bad injector and/or electrical harness or PCM issue)
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Cylinder Power Balance Test (How much each cylinder contributes. If the failing cylinder isn't fuel related run COP (Coil on plug) test to check for a faulty coil.
View attachment 1836451
Compression Test (If a cylinder fails in this test confirm with a manual gauge compression and leak down test)
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I've run these tests frequently for many customers. A qualified auto electrician should be able to have you answers on how and what failed in 5 hours or less.
^^^^^^^ This