Diesel Fuel Pump
Diesel Fuel Pump & Turbo boost feed.

There's not much one can do in this area except carry out visual checks.  Do not attempt any adjustments.
Check the diesel fuel pump and feed pipe for leaks. Check the Jubilee clip and tighten.  Check the Turbo input pipe Jubilee clip and tighten. Can be taken off for blockage checking. If blocked will reduce the engine power at higher revs.
Check the pipe for splits, vibration scoring and perishing.