They did do a crappy job troubshooting. I just tested that out and it's only when my ac is on, not when I'm just blowing regular cold air or heat. At any fan speed it does the jerking, when ac button is pressed. I figured I didn't have an IAC valve cuz no one was working on the same year as mine. I checked my battery and it was good.
Is it a constant jerk, or more like a jolt when the compressor kicks in? Is the AC cold? Or cold for just a few seconds? I’m wondering if you have a stuck closed expansion valve and it’s making your high side spike enough to make the car jerk like that. I would start with the motor mounts. Hard to diagnose without having at least a video.
It's not a constant jerk but it happens in intervals. My ac is cold constantly. Sometimes when I drive off it loses some power to take off. I would take a video but it wouldn't really show anything. It's more a feel thing. It doesn't make a different noise just a quick stutter then goes back to running fine. Like I said it happens in small intervals.
