Coil pack or Injector problems

[Sonny]

I am so close to solving my rough idle problem. I have never paid to much attention to spark plugs before, pulled them changed them tossed the old ones. Now I have started looking real close to try and eliminate the rough idle.

I have about 1k on new Motorcraft Double Plats. I pulled each today. Cylinders 8,3 and 2 have a glossy black glazing on a SMALL portion of the Porcelain, it will not wipe off. Other than that all the plugs are clean and makes me think the motor is solid.

Would this symptom be the result of a bad injector or a faulty coil pack, I would think if it was a coil all 4 cylinders for that coil would be affected???

I did narrow the Gap to 52 from 56 and the motor runs better so I am thinking a weak coil. Anybody know???

 

[section525]

Well typically with a coil pack only one coil will go out. So the other three will perform normally. Meaning, that this could very well be a coil pack issue. Also, the V8s go through coil packs like fuel. I've had three new ones so far.

 

[Sonny]

Could you clarify for me, does a coil pack have 4 seperate coils, 1 for each cylinder? So with 2 coil packs I really have 8 individual coils, or did I misunderstand your reply?

By my Chiltons, the symptoms would point to both packs being faulty as 1 pack serves 4,7,8,2 and the other 3,5,6,1

I do appreicate your help.

What were your reasons for replacing your coils?