Matt,
I replaced the spark plug wires about 2 years ago (500 miles). I don't see or hear them arcing. About a month ago, when I was first having the problem, the engine was starting and running. But after started and running, the rpms would go up and down (about 300 rpm) until warm. Then OK. My mechanic placed a code reader on the engine at that time with no codes being set. Would this sound more like the TPS or IAC? Now engine just turns over and no starting and still no codes. Is the TPS located on side of throttle body? If located on side of throttle body, would I have to replace complete throttle body or just the sensor? Where is the IAC and TPS located? Thanks for the tips............