Starting problems

Hi again. Well, I've had three great weeks of trouble-free SeriesIII driving and now have a problem that occured without warning. I used it on Tuesday - all ok. Today (Friday) went to get going and the engine would not start. With the help of the wife's car and jump leads I got the engine to fire up but it only lasted for a few seconds and it just died. It's a 2.25 diesel. Things I've checked tonight....

The shut-off cable retracts fully and is connected properly.
The fuel pump pumps fuel both manually and with the engine turning over.
The fuel filter has been inspected and all air removed
The two bleed nuts on the injector pump and pump control have been bled.

Surely all four injectors can't be knaff at the same time?

As a novice mechanic (lol) can anyone suggest the best things to check next to try and locate the problem?

Many thanks,

Skismo

At least mi starter motor still works, my red gear stick is in the right position and mi new seats are still stuck to the seatbox !!

Update:

Today I have removed all four injectors and connected them all up to the fuel lines outside of the engine block (to see them spray). They don't spray, any of them. Can it be that all four have suddenly stopped working or is there something more serious afoot?

My injector pump seems to be working ok in that all four fuel lines are squirting fuel out when the injectors are disconnected.

Can anyone help?, this is a learning curve shaped like a hockey stick for me !!!