Q - Hello, I have a 2008 f250 6.4 diesel. The truck will start and run at normal idle for a few seconds but will drop idle and shut off. Before this started happening the truck had no throttle, I could push the throttle and would not raise rpm. - Ryan

A - Morning Ryan,

The first step to figuring this out might be test and see if you have good fuel pressure.  If your low pressure fuel pump on the frame is quitting or not producing enough volume it may do what you are experiencing.  I would also take a good look at the lower fuel filter and make sure the cap is seated fully and not sucking air.  It definitely sounds like a fuel supply issue to me.