ML 270 CDI - Car runs perfectly and normal kickdown OK but if you give it a large kickdown eg. when overtaking, engine cuts out competely which is a bit scary when you have no power steering. Injector seals have all been replaced and diagnostics say "Rail Pressure Monitoring" as a fault code.
Not sure what it could be. Help need please...

 

Have today given the car another test run. From standing start car revs perfectly well upto 5000 revs. On normal kickdown also car drives well into high revs.
It is only when driving at normal revs and you want to give it a hard peddle to the metal kickdown that engine cuts out. And it cuts out at the 3000 rev mark if this helps.
Any thoughts out there because I am puzzled. Could it be MAF sensor problem?? (Was replaced 6 months ago)