Bit of an update.. I have dropped the tank, drained it, replaced the sender as it was a bit rusty on top, blown out the fuellnes and fitted new air/fuel filters. Not much change.

But....I changed fuel from caltex to bp and fuel economy is now sitting at 14.8/100km and the smoke has cleared up.

I still think the injectors need a service so that's next on the list and need to be checked anyway before the turbo goes on.