Hi. I have an X5 3.0D (E53) which has just recently decided to refuse to start. It just keeps on cranking but wont start. I have replaced the fuel rail sensor, the crank position sensor, the glow plugs, the glow plug relay, the regulator on the front diesel pump but it still wont start!!! The funny part is that when i remove the intake hose on the manifold and use quickstart directly, it starts immediately! I need help.