Thanks, Jim.

Well, I guess it's my turn in the barrel on the ETA. I just figured out what the problem is. I went back and re-read your Menu #24 and picked up your comment about the ETA making a mechanical noise when testing it. Then I remembered that there was normally a high-pitch humming noise coming from it when I would turn the key on without starting the engine. I guess that's the motor resetting itself.

Anyway, after turning the key on (engine off), when I moved the wire that runs from the canon plug to the ETA, I noticed that the buzzing in the ETA stopped. I couldn't get the noise to return no matter how much I moved the wire.

I turned the key off and on about five or six times and every time I turned the key on, the buzzing would continue until I disturbed the wire that went into the ETA. Then I went to the link on your site where the guy shows how he rewired his ETA, because Mercedes used that same great wire they used on the engine wiring harnesses. http://v12uberalles.com/throttle_actuator_rewire.htm

I realize now that the problem is probably bad insulation in the wiring--at least the wiring going into the ETA, and probably inside the ETA as well. The problem first appeared after I unscrewed the canon plug and, if I had to guess, I would say the wiring is broken between the canon plug and the point where the wiring mount bracket bolts into the manifold with an Allen bolt (second picture)

Rather than try to rebuild it myself, I was looking at the prices at the Jaytan link on your site and, of course, my ETA (000 141 78 25) would be among the most expensive ($799 minus $100 core). I think you mentioned that a new one wholesales at the dealer for $750. I'm thinking it would be better to get a new one.

What I found interesting about the ETA is that, even with the ETA apparently not working, the car still runs okay--other than no cruise control and a lower idle speed.

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles