Been a while since this post but had a death in the family and a bunch of stuff to sort out so this got put on the backburner for a while.
Finally got stuck back into it the last couple weeks and managed to make a bit of progress. I originally dismissed the injectors as the problem because i had already replaced them with a new set but it turned out one of the new injectors was faulty, appeared to be working and pulsing like the others but had a really weak spray, got that replaced and now it starts first time every time and drives a lot smoother, however still idles a bit rough.
While checking electrical connections I was using a noid light on the injector plugs and the idle smoothed out a little when i unplugged injectors 3 and 4 individually, not perfectly smooth but better than before, I expected idle to get worse so i thought this was a bit odd. Could it be overfueling maybe?
Ive also done a compression test and was all within range and ive since swapped the Crank, Cam and Oxygen sensors so apart from Knock sensors there is not a single original sensor on this engine that isn't brand new or swapped from a perfectly running vehicle. Also checked DFI and spark is strong from cold to hot.