I checked last night. No arcing. The idle seemed a little better, but I never let it get up to operating temperature.
The doghouse is off. I've been told that there isn't an Idle Air Control on this particular V10, but I see one. I'm going to try to get it off and run some cleaner in it.
I also somewhat got the Mass Airflow sensor out (another possibility). But I never got it all the way off and cleaned like I would like. It sits in back of the air filter housing. I don't see any good way to get it off. What have any of you done to get at it? I sprayed it down as well as I could inside the housing.