1994 Honda Accord Hot Idle Problems

My car starts fine and idles fine when cold. After warmup the problem begins. It's not exactly a misfire on one cylinder, but it's almost as if the engine "hiccups" to a low RPM and then returns to normal idle. Sometimes it goes away and it idles just fine for a while. I don't notice it when there is a load on the engine, only at idle.

I replaced plugs, cap, rotor, and wires. It's an old engine, so compression is about 100lb in all cylinders. I've checked the spark at each cylinder, seems fine. Like I said, though, it's almost as if the whole engine "hiccups" not just one cylinder.