Right, still not 100% confirmed yet but... I now think I have a couple of problems. First, the EGR itself is likely to be full of soot. Which I think in turn is causing an over-boosting problem. Either by sooting up the MAP sensor or affecting the movement of the vanes on the turbo.
So far I've confirmed the in-tank fuel pump is working, and that the injectors are getting fuel. Car would start but then die very quickly - like it was running out of fuel. After some investigation EGR now has a blanking plate in it. Car starts and revs (gently obviously) happily. Not driven it any distance yet. My assumption is the valve has been stuck open, so the engine didn't have enough compression to remain running?
Further updates once I've cleaned/deleted EGR. I'll even put actual pics of my actual car up too (shock horror!)
edit - I forgot to add. The latest OBD report recorded an error but only displayed a comma, no number or anything. "first time I've ever seen that" said the tester. Also recorded negative temperature and ambient pressure of zero. Which led me to believe MAP is dirty/buggered, but it now runs happily with EGR blanked. Still no coolant gauge reading though.
Last edited by DG_; 16-05-13 at 11:26.