I've owned this 2004 Sedona EX for a year (83K miles) and it's done this on and off since I got it (mostly on). When the AC is on and I'm in idle, reverse, or at slow speeds during acceleration, the car will hesitate/stumble intermittently and randomly. It is of short enough duration that I really don't lose too much power but I can see the RPM needle dip a little. Once I pick up a little speed (probably over 10 mph) the problem is gone or at least I cannot notice it. Occasionally if I'm stopped it'll cause the body of the van to move - won't make the wheels move, but I can feel the body moving. It happens most of the time, in hot or cold weather and any air conditioner setting. If I turn off the AC, the car runs normally. There is no check engine light on. Any help would be appreciated.