Really need help please. Our X5 seems starts up fine from cold. But after a long run just cranks and won't start. I work at a garage and then mechanics have tried to diagnose there problem. Diagnostic came up with a glow rail issue. So far have had low pressure fuel pump replaced. Crank shaft sensor replaced. Cam shaft sensor replaced. Glow plugs replaced. Still there. Drives fine just will not start after a long run. Any ideas? Bit lost here