Katie Lyman

2014 silverado 1500 Sometimes when I shut my truck off it will slowly shut down. Like I have time to take the key out of the ignition before it will shut itself down. You can hear it almost as if it runs out of gas and dies. Doesnt do it just randomly. Also I've had a pulsing vibration. Usually up over 35-40+ it will pulse. I've changed front u joint with no difference. Also wheels and tires have been changed since with no difference. Doesnt matter if on the throttle or off it will pulse/shake. Advice? Thanks in advance