Help need brought a sprinter 2008

[Kev r]

Hi hope some one can help me I have a sprinter 2008 that I can not get to run it try's and fires on easy start but dies and now it looks like oil or diesel coming in to the exaughst manifold check timming ok compression test show 375 to 395 changed hp pump did leak off test and got very little out of injectors but I did notice it's not holding much pressure in rail took return pipe off rail got no return so I'm at a loss and hope some one can help and I'm not getting any fault codes