Thanks guys, I tried a totally different ECU with a different chip and it did the same, blows as soon as the ignition is on with the ECU plugged in.
I'm away on holiday tomorrow for a week so thats fine by me mate, no hurry, she's back in the garage again waiting.....I'm off for a week after that but will be at home or nearby.

Got all the diagrams, and already started to trace them so thanks for suggesting that, be good if you could lend a hand and check i haven't missed anything. I was actually thinking what you said about completing the circuits last night when i was working on it, so I disconnected the TPS/SECS/Injectors but had no effect, i'll keep digging and maybe even start right from the column/ignition switch, cant hurt.