Chrysler 1999 T&C 150K

While driving idle seemed to increase. Noticed at red lite where van seemed to want to move forward with brakes applied. Went to parking lot put van in park engine RPM rose to around 2500 RPM on it’s own. Opened hood and fiddled around with a wire???/hose thing near the throttle control line (wire that connects foot piece to engine). A bunch of black powder (carbon?) fell out. Turned the van off then back on a couple of times. On the third time idle returned to normal and has operated normal since. What caused this? What do I tell my mechanic? What was the wire/tube thing (it entered what I assume is the air intake at a right angle) right in front of where the wire from the foot control hooks up.

You should just tell you mechanic exactly what happened.

S/he will probably clean your throttle body and check the operation of your throttle cable & return spring. Your black tube thing is probably part of the throttle or cruise control cable. Or it could have been a vacuum line or something - not much to go on there.