Okay, I finally got around to checking and replacing.

I tested the TPS with a continuity tester. It tested fine with the throttle both wide open and closed.

I removed the ICU (idle control unit) and found that a resistor had a hole burnt in the side of it. I bought another unit.

I replaced the ICV (idle control valve) with another.

The engine still idles high as it did before. I'm somewhat at a loss for words. It seems like I've traced down and resolved all potential issues. What else could there be?

-Troy

__________________
- - - '77 federal 280e - 222k miles
- - - '85 380se - 129k miles
- - - '07 Chevy truck
- - - '79 Datsun 280zx with '82 turbo motor
- - - Currently looking for a clean 190e with less than 160k miles.