I'm having problem with 2005 ford power stroke. It is hard to start in the morning. But after about 30 min of sputtering and knoking it will start to smooth out and run. I have a Bully dog on it. Once it wants to run I can break the tires and it run like hell. But the next day same old start think. 6.0 engine what gives?

Be sure to drain water and change the fuel filter every 10,000 miles. Injectors hate water. With today's low sulphur diesel fuels, many now have to use a diesel fuel additive. Here's one of the better products on the market:

AMSOIL - Diesel Concentrate (ADF)