I have a 96 5.8 F-250, when i start or stop it has a very bad hesitation and the speedometer jumps around. Now the crazy part, its not throwing any codes or no check engine light, when it gets warm, it will be fine or I push in the odometer button and it runs fine and the speedometer is correct. I have replace speed sensor in rearend, throttle position sensor, idle-air control, plugs, wires, cap.Any suggestions would be greatly appreciated