OK guys, by my name I am a Ford guy, but my father in law just bought a Dodge. Its a 1998 2500, Auto trans, Cummins engine 163k miles. He is telling me that he goes out to start it in the morning and it will idle for a little bit then die. It is a little difficult to start after that and he says it is blowing white smoke when it does fire up. He also says it's only getting about 11 mpg. He asked me what to do and I told him to buy a Ford. ha ha. Just kidding. I dont knock anyones pick up if it works for them. But seriously. Any suggestions.

 

12 valve or 24 valve? They changed mid '98. Maybe minor, like air or fuel filter.
If 12v, possibly overflow valve, deteriorated fuel lines, bad fuel heater, fuel solenoid, or slipped timing.
If 24v, check fuel pressure (very important), could be lift pump, IP, or electronical.