Fuel inject.system fault however no loss of power

[comptons67]

Hi All

A couple of weeks ago i had the Fuel inject.system fault come up on my dashboard, i dropped it into a a trusted local independent he put it on the diags and told me it was either the high pressure fuel pump or the fuel filter. (low rail pressure was the diagnosis) I had the fuel filter changed (cheapest first!) i then drove the next thousand miles completely trouble free, but then the dreaded error has now come back whilst accelerating on to the motorway. It went into limp mode so i switched it off and on again error still showing but driving perfectly, not in limp mode, no rough idling, fuel economy normal and as spritely as usual.

My questions are
Do you think it is the high pressure fuel pump considering it is driving fine
am i ok to drive the vehicle as is, i am currently 200 miles from home (don't worry i wont sue and not waiting at the roadside for a response)
Could it be anything else? no leaks are visible so fuel lines should be good, not smoking at all, to the untrained eye (i am) all seems to be perfect apart from the error message

The car is an E53 X5 2005 3.0 diesel sport exclusive the higher bhp model.

[X5Sport]

If it keeps running fine then head for home.....just be gentle with acceleration so as not to annoy it.  It might be wiring as well as a pump issue, or even just a pressure sensor issue.

[fenj66]

ive had the same issue with mine under hard, prolonged, uphill acceleration.
the car still drove fine though. after stopping car and switching ignition off and on again, the message dissapeared and never came back. i put it down to a clogged fuel filter so changed it anyway. but I'm not sure what is was.

[comptons67]

Hi All

Just as a quick update, i got home (thanks for your concern) i had the car put on a diagnostic machine and the following faults came up
4560 Rail Pressure Plausibility Delivery Controlled
4570 Rail Pressure Plausibility Delivery Controlled

I dropped the car into Auto Marine diesel services in Hove, they have found that 4 of the injectors were basically knackered and the other two were border line, also worth noting that the injector didn't show as being a problem until the engine was properly warmed up so keep that in mind if you have the same issue.

I have decided to replace all 6 so to make sure that it is solved once and for all. An expensive option but the right one if you want a reliable car.  I will update you if this has been a total success story in due course.

Cant wait to get the motor back though as the clutch on the 911 is really pigging stiff!!

[comptons67]

Hi All,

Car has been returned and all is working as it should do, I cannot thank Automarine diesel services in Hove enough. Great service and kept me upto date with everything every step of the way. To diagnose the fault and replace all 6 injectors they charged me 3 hours labour!!  I could of probably saved a few quid on the injectors by getting them refurbed rather than replaced but I needed to get the car back quick!!

[DARTH510]

Hi, I had exactly same issue on mine.  Go over 4k revs or boot it and fuel injection  warning came on, car went into limp mode. Sometimes it would clear on its own, sometimes I had to use my scanner to erase code, but always the rail pressure code. Dropped it off at my local garage, they replaced the diesel fuel filter and problem cured.

[comptons67]

Hi Darth510

I did go for the fuel filter as my first hope, cheapest first and all that but the problem still occurred. All I can say is that you were the lucky one!