Diesel running back to tank

Hi guys, I have a 2006(56) skoda Octavia vrs TDI and when the car sits for a couple days and I go to start it it cranks over but doesn't start,unless I keep cranking it over and over and over,but I hold the key on until all the lights on the dash board are lit up and wait few mins until the diesel pumps up and after the car is warm enough after driving even if I park it and return to the car after a hour it will start normal,can anyone help me with this?? I replaced the fuel filter and still the same problem.


I think the problem is that the diesel is running back to the tank for some reason