Engine Misfires on cylinders?

I put in a new coil pack, but was still missing. Then I put in a new spark plug and seemed to still be missing. I left the car alone for a day or two and now it is running fine. Must have taken some time for the "brain" to readjust itself after running a few times.
Thanks for the answer though, because you were down the right path to getting it fixed.

My SUV has a misfiring on number eight. I have changed coil packs, plugs and wires. Before I changed coil packs it had random misfiring it would jump around from six to one to three to eight, after new coil packs only on number eight. Does anyone know what it could be? Also, I put new fuel pump.

I have had problems over the past several years with a nagging engine skip. Two years ago I had it in the shop for this miss and they determined it was bad plug wires. They changed the plugs and wires and it ran fine for 2-3K miles.

It developed a skip again and I put it into the same shop where they replaced one plug wire as bad. I think it was number 7. It ran fine for a few months but developed a skip once again.

I found a bad wire number 4 I think. The insulation looked like it was chaffed so I replaced it. It ran fine for a few more months and the skip is back again.

Weather seems to make it worse. Rainy days are worse that dry days and since there is no distributer cap I'm at a loss.

The check engine light comes on each time the miss is bad. I clear it by diconnnecting the battery.

I think there is another bad wire but think also that this fix is only a band-aid since the problem keeps reoccurring.

Is this an ignition coil problem? Can that make the plug wires fail? And is the coil the same thing as the coil pack or are they different things?

Any help would be appreciated.

Thanks
Mike

Thanks for the input. I'll make the change, though I think that was done by the shop the first time. They had mentioned that the plug wires were not the proper ones for the truck. I bought it used in 2001 so I didn't know what was in it.

The wire I replaced it with was not a Motocraft wire however so it may be bad again.
Mike

Seems to have solved the problem.
Thanks