things to check on the engine.

Basically before the cold rolls in I want to make sure my engine is running its best before winter. So here's some questions for anybody patient enough!

Turbo, I know mine is leaking a fair amount of oil. nothing that can be seen in daylight, but at night anything more than gentle throttle adjustments sees white smoke out the exhaust. The top of my fuel pump also fills with oil. Is there anything I can do to stop this?

Power, off turbo she is lovely. However on turbo it seems to hit a wall at around 3000rpm and then it goes flat. The pump is tweaked, but not excessively. Is this normal?

Injector/diesel treatment, what exactly do they do, don't say clean... Is it worth it and will I notice any difference?

Speed/throttle, speed is not an issue, its good for 80. However, I normally drive everywhere at 60 and it seems that the throttle needs to be at around 80 to 90% to maintain it. Again, is this normal?

The engine has 175k on the clock, returns between 30 to 37!!! Mpg. 265/75 tyres and a disco transfer box. All oils and filters changed, brakes free etc.

Thanks in advance for any replies.

new turbo or yours reconned ,wastegate opening limiting boost? ,throttle cable is adjustable on pump bracket

Thanks James, what would the throttle cable adjustment help?

probably nothing but theres often too much slack in cable, blueish smoke ,burnt oil ,white smoke unburnt fuel if hangs about in air ,water vapour if disappers quick ,black smoke is too much fuel burnt in too little air, turbo leaking into pump is obviously passing too much oil, fuel treaments /cleaners all seem to be mostly petroleum naptha ,which amongst other things is lighter fluid,putting oil in fuel does seem to make them run better whether it be two stroke oil ,engine oil or additive

Thanks