I'm getting an intermittent misfire that happens occasionally at idle or when the engine is "pulling the load". What I mean by that is on the freeway when you go to accelerate but not enough to cause a downshift I get a definite misfire and it's not all the time.

If I give it a bit more pedal or manually downshift it performs fine. Plenty of power and screams up to 7000 rpm without missing a beat.

Plugs are clean and have about 4000 miles on them. I have 1 new coil and the other 7 are the originals. No oil down in the plug holes at all to cause a short.

I've run into this issue with other coil on plug setups like my wife's Aviator and the only way to figure it out was take it to the dealer to get hooked up to a special diagnostic tool. However since coils for that are cheap, I bought a new coil and swapped it between the 8 positions until the problem went away.

Coils for these cars are 10x the cost of the Lincoln coil so I was wondering, is there a way to test them with a meter or some other simple method?

Thanks, Ken