Spark plugs

[cyclostang]

I'm sure this issue has come up many times, buy I have to bring it up again. I'm having a idle misfire felt and seen in the tach. Always worse in gear when at normal temp.
Feels fine when on the gas and cruising. even torque checking.
I have motorcraft finewires in it, with not even 1000 miles on them. I know the gaps are right. Several other ford guys i talked to have had the same issues(not the 3.4) and fixed their idle problems taking out the motorcrafts and putting autolight cooper cores in. Since this isn't really a ford engine, what do you think?
I know I have good cop's in now. Last time I did a power balance check and the scope showed random misfires, some cylinders worse then others.
Thanks for feedback/advise. 123K.
Greg

 

[SHOZ123]

Bad coils probably. I had good luck with the Autolite XPs.

How do you know you have good coils?

 

[BamSHO]

Im running Finewires in all my cars here, never had any issues with them. I argee sounds more like a coil going out, prob one of the back ones.



Brian Michael
98 black Gen3

 

[stephen newberg]

Seems to me Paul had the key question: how do you know you have good COPs on all 8 cylinders?

pax, smn

 

[rodrigoflip]

I had a similar issue after replacing my plugs. It ended up being an intake leak from one or more of those old intake couplers. Just throwing that out there since it may be a possibility.