i have replaced wires, plugs, coil pack, and now...the ecm...nothing!!

Are you sure it isn't getting spark? Or could it possibly be that cylinder isn't getting compression? I'm assuming your trying to troubleshoot a misfire, correct?

If you have one plug wire not getting spark then it has to be in the coil pack.

yes...i pull the wire off the coil pack, and there is no spark at all....all the other ones have spark...and i have replaced coil pack

You either got a faulty coil pack or are having power problems to it.