Just to give you an update on this battle of wills.
I had a fresh start on this after swopping the ecu & bsi, got the multimeter and wiring diagram out and started taking some measurments around the double relay ( the brown thing next to the ecu ) and it soon became apparent that there was a lack of power from one of the outputs to the ecu, maf & other bits. The fuse was sound and so was the multipole connector at the front, out came the stanley and i opened up the loom from the connector to the engine and there it was! bingo, another corroded wire
Repaired that and it started first time, seems the bsi could recognise the key but couldnt wake up the ecu as it had no power.
Now got another problem with the eml light but no limp mode even after disconnecting the battery, well it did get a few miles up the road
Anyone got experiance of cleaning high pressure pump regulators?
99 HDi Estate 110 fast approaching 200K. edit: now 215K