Outer Limits 4x4 Board

(1997, 200,500km, LWB, Wagon)
Especially when towing the caravan, less power, and a lot of grey/white smoke when fully accelerating from start and when accelerating from 80km. Cruising seems to be OK. Now I feel I can not feel the turbo cut in at 2000rpm + now.
I have had the Turbo checked, it is “making boost” the tappets checked, new fuel filter, but no obvious fault. There is no dyno testing in this town of 45k in out west NSW. Other than a complete rebuild of the pump, they could suggest nothing else. Oh $308 for that advice, no parts.
5000km ago I had full dyno tune, (Diesel Care) Horse Power, smoke emissions, adjust pump pressure, turbo boost pressure check, fuel settings, with ultrasonic cleaning of the injectors (whatever that is but it cost $250) fuel lines blown back to the tank and whatever, but $610. Advised that an increase in HP would now be available. Driving the 200km home in the “bush” I did feel an improvement.
I am sorry to make the story so long, but felt the need for some detail so hopefully a diesel guru can give some advice on where to go or do next.

The smoke you mention doesn't sound really comforting. Usually this colour means the engine is using oil, either via piston rings, leaking turbo seals, or worse.

When they checked the turbo, did they actually remove it and go over the turbo, or just check to see if it was making boost?

The fact that you can't feel the turbo spool up tells me that you either have a crook turbo (but is apparently making boost), or a tired motor. Have you had a compression test done on the motor?

Have not had a compression test done. To my knowledge the turbo was not removed.. I am nearer to Mildura, so any suggestion of who might be able to give me advice wold be appreciated.