Check the small things first. Like the spring that pulls it back. Pull back on the arm wtim your finger if it idles down then try replacing with another spring. Or move the arm back and forth to rev up the Jeep and see if it is hitting the adjustment screw. If it is back the screw out slowly and count your turns just incase you need to put it back in the same place. Sometimes the adjustment screw can change on its own just from the Jeep shaking. Start with that first.