I figured it out myself over the weekend. I removed the main hoses leading in to the throttle body. I ran my fingers in the throttle body and felt a foreign object stuck in one of the butterfly valves. Upon removing the throttle body, I found pieces of an old air filter lodged in the butterfly valve. Here's what I think happened. When I bought the RV recently, I told them to change out the air filter, among other things. The air filter is difficult to reach, requiring you to loosen 2 screws from the inside of the cab and loosen 2 screws from the outside. I think they just loosened the 2 from the outside and literally ripped out the old air filter, leaving parts of it behind. Then, they forced in the new air filter (parts of it were bent and compressed), not realizing that they had left filter fragments inside (or not caring.) On this last trip, they were sucked up into the throttle body and gradually became wedged in the butterfly valve.
Monday, November 24th, 2008 AT 2:40 PM