Starting/running issue
 

I need help solving an issue I have with my 1996 Mercedes 300D. My experienced mechanic has run out of ideas for trying to solve my problem. It seems to be fuel related. The car runs fine when it runs. This winter I was having problems with starting. If I used the block heater, it would start, run for about 1-2 minutes & start sputtering. If I held the accelerator down, keeping the car at 3500 rpms +, it would get through this sputtering but it created a tremendous amount of white/blueish smoke. This would go on for about 3-4 minutes until the car warmed up. Once it was warm, all was well. Then, recently, it would conk out after running for maybe 15 minutes or more. The fuel tank is full, we've replaced the filter & there seems to be no restriction between the tank and the filter. If we re-prime the filter, it starts right up but stops again in 15 minutes. The "check engine" light stays on although I can reset the main light using the dash button. Any ideas?

Since you mentioned that when you reprimed the Fuel Filter it had a positive effect it could be that you have an Air Leak in your Fuel Supply System.

However, I am do not now much about the newer Cars.
I hang out at another more active Forum and a lot of them have your year and model.
I would start a Thread on that forum.