Hi I have a starting problem as many other SDI / TDI owners seem to have reported where after a few hours stood the engine cranks several times before starting due to air in the fuel lines due to fuel bleeding back into the tank.   I have replaced the clips on the low pressure fuel hoses with jubilee clips as well as changed the fuel filter and the return valve (incl o-rings) but this didn't work.   I took the lift pump out to check the NRV and it has failed and fuel leaks out of the bottom