Ok for starters haven't been here for a while but I've had the same car for about 4-5years now. Recently in the last year, I've had a few issues with no start, stalls but now erratic idle. Like seriously-my rpm's surge up and down so wildly I'm scared to do major damage to the engine. I brought it to a Volvo mechanic who's worked on my car a few times and he suggested I replace the idle control valve(this was like 3-4months ago) The problem wasn't as severe and I managed to get my car to limp home. I got the part used-replaced it and replaced a hose that connects to one of the T junctions on the valve. The car eventually started and after unplugging the idle control valve the rpm's seem to settle and I was driving around just fine. Now the problem is back big time. I'll explain better but please any help in what to look for next would be helpful. And please talk me like I'm 5 cause I'm pretty much teaching myself.