I have a 2006 F 250 diesel. The car will start when cold, but not when it has warmed up. I will have to wait a few hours and then it will start again. Cycling through the glow plugs 5 times seems to help. I did find a fuel leak at the top fuel filter and that was replaced. I definitely starts better after that but we got stuck at Target again the other day. When the engine is on it seems to drive fine... seems to have full power.
At first, short stops, like getting gas, it would start fine. That seemed to be getting worse as time goes on. Battery is good and it turns over easily.
My best guess is that it is not getting enough compression/pressure at startup. I read somewhere that there could be an internal oil leak at the glowplugs. When the oil is cold it is viscous enough to allow enough compression, but the hot oil lets the compression drop.
Any ideas on where to start?

See if this fits:

On diesel engines that will not restart, after they are warmed up, it's often a sign of a tired fuel pump. As they heat soak, inside pump head clearances increase and it will no longer develop sufficient fuel pressure at cranking speed. While it's running, fuel helps cool the pump by carrying the heat away.

Be sure to change both the under frame and under hood fuel filters regularly. Only use SAE 5W-40 full synthetic heavy duty diesel engine oil in your PSD.