rmortime

Thanks Torque. I had to wait a surprisingly long time to get those test to run.

My misfire are only occurring at extreme accelerations or heavy load uphill and i'm registering misses on just about every cylinder while running premium gas, 92. Going to change all the plugs this weekend. Ended up taking the gf's new car home to michigan.

redfishtd

The back ones are famous for being loose-- number 4/8. Many shops skip the hard plugs . They must be torqued in 25 to 28 pounds, don't even think you can tell by hand . . Start by hand carefully ,alum threads are not to be trifled with , finish with torque wrench , Clean out holes with air before you start. Usually I pull pcm to get to number 4 .
Read the tsb from ford on plug changing use dielectric grease and new boots . I change mine at 30k and replace boots . I use nickle antisieze per ford on tips .
Some of us like to clean out carbon around the tip area of the head so as to not damage new sparkplug forcing it thru the hard carbon . Use carb cleaner but make sure it has time to evaporate as you do not want to hydro lock cly .
I really didn't see blow by on those porcelains at least not 5/6 . The carbon on porcelain leads to tracking/misfire. .
Buy all the small extentions/wobbles /flex head ratchets from harbor freight to make it easier on yourself . Clean your cop tips where the spring attaches and use small amount of dielectric grease on boot at this end too .
good luck