My X type is driving me to drink!
Have had intermittent power loss problems, this seems to have been cured by fitting a new MAP sensor. The beast now goes like the proverbial Sh*t of a shovel, as long as you do not bury the go pedal into the carpet! If you do the engine will drop back to limp mode with heater lamp light flashing until you turn the engine of and re-start. I am getting fault codes relating to Injector control pressure(P1211) and (P0251). The car runs and starts well with no smoke! Any suggestions?

 

Past experience with my diesel x type the low common rail fuel pressure was attributed to a faulty injector which was leaking back to much. If I were you I would firstly replace the fuel filter and see if that cures it. If not then try replacing common rail fuel pressure sensor, fuel pump temp and pressure sensors. Do a leak off test on the 4 injectors. I am afraid its trial an error until you find out what is causing the drop in fuel pressure. More issues could be with a failing fuel pump or even a leak in fuel line causing it to draw air.

 

Thank you for your help twinstacks, I have already replaced fuel filter, my next move was to try the fuel pressure sensor. I am trusting that as the engine runs with no smoke and pulls well when the gas pedal is used sensible that the injectors should be ok. At least have got the S type going properly now!

 

Try a leak off test of the injectors. If there is a way of seeing live data try watching common rail fuel pressure when you put it under load and see if that drops away. I am afraid it's a game of ilimination.