Q - I have a 2006 Ford F250 6.0 Powerstroke it doesn't want to start in the mornings unless I spray starting fluid in it which I know it's a bad idea but that it runs fine all day but next day the same thing what could be the issue?

A - My guess would be that the glow plugs are not working properly.  They could be worn out and not getting hot enough or the glow plug controller could be bad and never turning them on.  I would do some diagnostics to check them both, but replacing the whole glow plug system (plugs, harnesses, controller) might be a good start.