Hey guys...I was taking a turn tonight, and out of nowhere, my car shut off. I stopped (had no choice

), checked the engine, and noticed my coil pack was just hangin' out behind my timing belt. Basically, who-the-fucking-fuck-ever did the motor swap on my car REALLY AFRO-ENGINEERED the job. Anyway, so I pull the coil pack out of the crevace between my intake manifold and my master clutch cylinder, and unfortunately, I unhooked one of the spark plug wires from the coil pack. I hooked that one wire back up, and drove home.
Unfortunately, though...ever since this "shut down," my car has been vibrating like hell when it accelerates, and it sounds like a Harley. Also, the tach needle bounces around in a seemingly sequential pattern (up, up, down, up, etc...not really, but just as an example so you know what I mean). Does this mean it's misfiring?
I tried unhooking all the spark plug wires and putting them back in the respective places, and I'm still getting this. On a better note, though...now my car idles at 1000rpm instead of 2000rpm. Any help would be appreciated.