I am SOO tempted to say "call my friends at Ringlift", but that would be rude, so...first thing will be to post an accurate serial number, and then make sure the accel pot is connected and not out of adjustment, also check to see that the wire to the transmission speed sensor is connected. It is the bottom most wire on the truck, and sometimes gets pulled off from driving over trash or debris, just look under the truck and make sure there is no wires hanging disconnected.