engine runs rough

I recently overhauled an 86 four cylinder engine, and it runs fine, idles fine, but with no load, it misses at 2000-3000 rpms. Any one have any ideas?

Run the car in the dark and lightly spray the plug wires with Windex, if there's bad insulation you'll see sparks jump. This *might* be the problem. I've seen brand new plug wires that were crap after a day on a 4 cylinder Fiero. I'm told the trick is to put split loom on the wires to keep them from arching, and make sure the wires do not cross each other or touch metal at any point. Other then that, I can't think of what would cause a miss like that.