So a little back story. A few weeks ago my 1989 Volvo 240 started having issues with hesitation when I would accelerate. After a lot of research, my check engine light came on last Sunday and I ran the diagnostic and discovered my idle air control valve signal was missing. I examined the part and, what you know, the connector was disconnected. I plugged it back in, and this fixed the issue. However, my car was idling a little too high. The next day I noticed that the throttle body sensor connector was also disconnected. I reconnected it and have been driving it for a few days to let the computer do its thing but I'm still having issues with the idle being too high. It doesn't always do it though. Most noticeably it happens when you're going down hill and you can feel and watch the RPM's go up and down. Like it keeps trying to correct itself. When I connected the throttle body sensor, I was hopping to hear a clicking sound but it just fits over it. Does this mean the throttle body is going bad? Would cleaning it help?