Just when I thought evrything was running well with my 2.5td P38, another problem appears, SIGH!!!!!!!!!!!!! the joys of P38 ownership

A few times during the past week I have had a total power loss while driving, absolute zero power and engine warning light on, power loss last only a few seconds and returns to normal and warning light goes out.

Any ideas anyone?

All help most gratefully received, many thanks

You need to get the fault codes read, but crank sensor is a likely reason. Engine revs are computed from 2 sources, the crank sensor and the needle lift sensor. Lift off the throttle and the signal stops from the needle lift sensor, if the crank sensor is faulty the ECU does not know the engine is running. Could also be the needle lift sensor and a number of other things.
For example the fuel filter, when was that last changed?