My Bronco is still in the shop. It started out with a squeaky Serpentine Belt that I had fixed via Idler Arm Pulley and new Automatic Tensioner. Then, it ran rough. So full tune-up, plugs, wires, cap, complete fuel cleaning. After that, voltage was all over, so new Alternator. Now, after a new IAC valve, its back in the shop because it bucks while driving and STILL idles rough? They're trying to pinpoint the issue, with no luck. Truck only has 106,000 original miles and truly has been well taken care of. I'm at a loss.