Ive got a 2005 f550 and she wont start it will turn over but nothing i can hear the computer cycling and the fuel pump pumping but nothing . My dad said to plug in the block heater and a couple hours later it fired up . what is the problem is it glow plugs or injectors or is this a computer problem any help would be great

 

same exact thing happened to me it ended up being the ficm

 

Google search the FICM test/repair procedure, and try that. It's VERY simple to test, but you will need a second set of hands.