Discovery TD5 misfire

Tried a search through the various threads but still struggling to understand current problem.
Car misfires from idle, struggles to get upto any speed and after a few miles dies. Over the last couple of years I have replaced the pump, air bleed valve, fuel filter, FPR and injector loom. There are no leaks and the oil level in the sump is constant.
All the posts on the FPR seem to be about leaks rather than performance issues - is the FPR likely to be at fault here ?
Don't really want to do the injector rings unless I have to.
Any thoughts or ideas welcome.
Thanks

Like you, I tried all the solutions you mentioned having experienced the same symptoms. At the end of the day, replaced injector copper washers, not as difficult as it sounds, now 100%! new life in the engine. Starts better, more responsive and just keeps going.

chrimcne said:

All the posts on the FPR seem to be about leaks rather than performance issues - is the FPR likely to be at fault here ?

Click to expand...

Yes it can. And the usual symptoms of the FPR not doing its bit --keeping fuel rail pressure high-- are lack of power, misfiring, etc.

Try get fuel pressure measured to assess fuel sender/FPR condition.

Also check for oil in loom as this is a recurrent problem, i.e. replacing injector harness stops oil ingress (for a period of time) but does not stop existing oil in loom from continuing to migrate towards the ECU red plug.

In addition to rough running, bad injector copper washers would typically give starting problems & repeated purging (fuel pump hi-pitch gargles). Experiencing this?

Ideally need to get a hold of specific diagnostics equipment to rule out any engine management issues.

Rgds
Matt

Many thanks Matt and Derek - washers and O rings replaced and engine running perfectly. Also took some advice on replacing injectors from this thread, http://www.landyzone.co.uk/lz/f50/td5-injectors-177950.html
Regards
Chris