Truck Repair: Freightliner cranks but wont start

Question
I have a 2004 freightliner 14 liter detroit engine with egr. Engine overhauled 200,000 miles ago. On cold days engine cranks but very hard to start but when it starts it will blow white smoke for the first 30 seconds and engine runs tough hesitant. And sometimes doesn't start except with starting fluid (on cold days). Check valve just replaced and that didnt help. Please help.

Answer
Had a driver have this and had him replace the restricted fitting on the return line on the back of his head and that solved his problem. If not going to be a process of elimination would remove the ouptut of your pump and attach a short hose to a bucket and watch for air bubbles if none would move on to the return line coming out of the head and do the same thing.