Last night I worked some on the car. I changed spark plugs and plug wires. I also removed the IAC and tried cleaning it. I used some carb cleaner, Q-tips, and a towel to clean it out.
I put it all back together and started the car. There is no longer any arching going on, and the engine is running much smoother. It had a pretty nasty shake to it before. As far as the surging rpms at idle, it is still present, but to a much lesser extent. The tack would sit right around 1500rpm and would fluxuate up and down about 100 rpm.
It still isn't idling smooth, and the idle rpm is still higher than it should be, but I'm not sure now that the cause could be. It could be that the IAC is bad, but it was just replaced 3 years ago and seems like it shouldn't be completely shot yet.
I did notice that there was not a gasket under the IAC when I removed it. I don't know if there is supposed to be a gasket or not, but there wasn't one.
Is it possible that there could be a vaccum leak? When the car is running, I can hear a light hissing sound under the engine coming from somewhere near the air intake/manifold.
Friday, October 15th, 2010 AT 8:19 AM