My(2006) f250 6.0 starts fine when it is cold. but afterrunning it for a while andit ishot, it turns over fine but will not start.spraying astarter fluid between the air filter and turbo, it starts instantly. I have changed the air filter and oil. same problem. In the beginning when this first started,the cranking time seemed to be getting longer and longer..

does anyone know what i may try?

 

update: all it took was fuel injection cleaner for diesel engines. truck runs great and starts every time. fyi