D2 Auto Failing fuel pump symptoms

Been driving the TD5 all over locally today and called in on a mate tonight,when I came out,started the TD5,it fired and then immediately died and no amount of cranking would get her to fire(she normally starts first turn of key).I checked the electric pump was running,and could hear it whining away but it did not stop-so maybe not reaching pressure set point-Also checked immobiliser led not glowing.Left for a few minutes and tried again and she fired into life,and then drove home ok.
Had another occurrence of this back in July-had just driven home,and had to go out to collect daughter-again TD5 (which had been running 5 mins earlier)would just crank over but not fire-to avoid running Batt flat,got daughter with other car-on retrying TD5 when I got back it burst into life and that w'end went to Dorset and back camping with no issue at all.
Does any of this sound like a failing fuel pump?I run home brew bio and on my third year-maybe my fuel savings are catching up with me.
I do have a Nanocom but not sure it would tell me anything-thoughts?

pump runs all the time ,it shouldnt stop,you can check iflow by removing bung or switch on bottom of filter ,placing a container under it and swiitching ignition on it should pour out in a smooth stream

Will try in morning James-thank you-nice to see you back

it seems like other problem than the pump, you really need to plug in a tester cos it might be a crank sensor or other management issue...if no fault codes then it's a fuel supply issue, let's hope you dont get a "topside switch" fault code

Thanks SF-will plug in my nanocom and see if it shows anything-although will it show anything if it runs?

If there's some management issue other than such ECU missbehaviour that the ECU to not store codes even if faults are present(quite unlikely but possible) there should be fault code(s) stored, maybe you get some crank signal fault or something... meanwhile swap relay R9(main) with R8(heated screen) to rule out a main relay intermittent fault, also when it's cranking but not starting unplug and bridge the terminals in the inertia switch's plug to rule this out too

Well she started fine (typical)-so I plugged in Nanocom and only fault listed is no airflow(Maf is dud,but I knew this)-no other faults at all.
In your opinion is it ok to start engine with Nanocom attached or should it only be plugged in once engine is running-ie can I leave Nanocom attached for a few days?
Not tried the relay swap as quite heavy rain here at the moment

might not be a good ideea to let it plugged all the time at least not over night cos there could be a certain drain though as the feed in the obd port is permannent... though you could drive with it plugged set on record mode for the fueling inputs cos if it cuts out while it's recording there might be a clue in the data log... you are driving it with MAF unplugged if you know it's fubar'd arent you? .... cos in case the MAF's fault is some intermittent resistive short circuit it can make the management to cut out and give difficult starting symptoms.

No I have not disconnected the Maf-but I will do now,just in case it is causing problems(I will order a new Maf)

Well I had a chance to play today.Unplugged the Maf and started her up (no issue).She started fine and appeared more lively to throttle response(or did I imagine it?).
With just the ignition on ,I undid diesel filter bottom bleed and confirmed a steady stream of diesel-but the pump does stop after a while-ignition off and on again ,makes the pump run again-I guess it waits for a signal from engine that it is running to stop it running needlessly.
I then checked the red plug into ecu,there was some oil so for the moment I have cleaned up as best as possible,whilst I wait delivery of a new harness and Maf.
One point of note,before I cleaned the oil(as best I could),my Nanocom would not achieve a ecu connection without the engine running,whereas now it achieves connection with ignition on as well.Maybe my two intermittent starting failures were due to a duff maf and oily harness

pump runs continuously when engines running

yes but not more than 3 minutes if only the ignition is on without engine running

Yes I would guess it is about 3 minutes with only ignition on(engine NOT running)