Diesel Starvation

I have a LR90 1989 2.5td, after hard acceleration she starts to missfire as anyone any ideas.

changed the fuel filter recently ?

Not sure just bought it

Blocked breather pipes to the tank, partially blocked pickup in the tank or fuel lines. If it's got a hand priming pump on it you could take the inlet pipe off the fuel injector pump and operate the hand pump (you will need to bleed it after doing this though). If the fuel is not coming out nicely it's likely to be a problem with the tank/lines/filter.