d4x4

If you change the bcu or the engine ecu they will set to the one with the highest mileage I believe. ?

When you remove the fuel pressure regulator there is a filter in the cylinder head. It is underneath a black o ring. Very well disguised. That can get blocked and cause problems.

There is a pipe about 3 inch diameter which runs across the front of the engine . It rubs through on a bolt on the left hand side of the engine. Check the underside of it. It's worth a look. No dismantling needed

There is a fuel pipe which goes from a connector on the inside of the rear chassis to the fuel tank. They are really common for failure. Main dealers will know exactly what pipe you need its so common. As for the engine leak it is almost always the fuel pressure regulator which is situated on the cylinder head at the back on the drivers side. If you take the top engine cover off you can see it clearly. The diesel runs down the engine and picks up oil on the way so its hard to tell what fluid it is.

They often leak round the tailgate glass. Brobably not enough tension on the seal. The glass tension can be adjusted by removing the inner door card. There are 2 adjusterable screws low down on each side of the window regulator. ( regulator mounting bolts). Adjust so the glass touches the seal on the first click of the tailgate. When the door is fully closed it pre loads the glass and makes a good seal.

If you are able to remove the pump(special tool needed). You have done the hard work. Clean the pump to remove any dirt. Undo the 4 bolts gently lift the top off (nothing flirts out) change the seals note which way up valves go etc. Keep everything clean.