Got another 300 tdi disco but she has a starting problem. runs perfect once going but does not like starting? It sounds like she bleeds her self every time she starts. but not 100%. any one got any ideas

Hi Got a very big problem. running up the m5 on friday and the engine just dies. no bang just felt like it ran out of fuel. Got her back to the workshop and had a good look throw. cant find any ting wrong. then she didnt wana start. We gave her a tow down down the road. wow she started. but...