Engine cut out

Cutting dead sounds electrical so my question is what's the rev counter showing?
anything on crank?
any/no RPM?
but anyway your going nowhere without data,
so code read is a must,
and pre 04 diesel code readers are rare,
Your going to have ti find someone with Vaux software,
I can tell you that "Opcom" or "Tech II" will read it.
These are pretty cheap on Ebay.

Nothing on rev counter. Engine turns over fast enough but does not start. Are opcom and tech ll readers or software? Will check ebay

Nothing on rev counter. Engine turns over fast enough but does not start. Are opcom and tech ll readers or software? Will check ebay

Both are software and interface,
around £20 for OPcom which I use,
runs on a laptop.
either will read you old diesel.
a lot of readers will not read pre 04 diesels.
I know Opcom will read yours.
But going back a bit,
no rpm reading suggests no crank angle signal which means as far as the engine ECU knows the engine isn't even cranking over!
So buy Opcom or buy a Crank angle sensor.
CAS signal is fundamental for engine operation,

Sorry.
should have said.
on cranking over speed for a diesel I'd be looking for 200 rpm,
minimum,
That isn't always clear on the rev counter but you should see movement.
Now if you had Opcom it'd be clearly displayed.
or not if the CAS was dead.

I have ordered the opcom software and interface from Amazon. have tried resetting the ecu by disconnecting the negative lead from the battery for half an hour, I have also ran another earth wire directly to the battery, as someone said the ecu suffers from a bad earth connection. Will check for any rpm when I next crank the engine over the other suggestions didn't work Was going to change the crank sensor next anyway, so thanks for that, was going to disconnect the immobiliser to see if that did anything, but can't find it.

ok turned the engine over today, rev counter shows around 150 to 200 rpm, can't be more precise without the op-com software, but at least it shows the crank sensor is working.

Progress!
diagnostics is a process of elimination/confirmation.
you've confirmed there's a crank angle signal so now you need to see live data for the fuel rail pressure,
Back to Opcom,
but you can try a very small sniff of easy start gas into the engine air intake,
it "should" fire briefly and then die,
this will confirm or not the state of the compression,
if it doesn't even cough briefly into life you have a problem with compression/timing.
DON'T USE TOO MUCH EASY START OR IT WILL BANG LIKE FECK AND POSSIBLY DAMMAGE THE ENGINE!!!
One other thing for you too clarify,
the state of the little key symbol on the dash,
it should go off as the key is turned to the accessory position,
i.e. oil light and alternator light and others lit/
does yours go off?
if it stays on then you have a key transponder recognition fault,
basically the key lamp is still on?
the engine imoby is still on so there'd be no ignition.
Good luck.