VAG 2.4 Diesel woes

[ELAN+2]

I have been lured by the thought of free fuel (cooking oil) and bought a Volvo 940 TD Estate, the one with the LT35 six pot diesel lump, Its got a sizeable fuel leak on one of the injectors, the drain pipes(the rubber ones) have been changed and the fuel pipe union has been nipped up (it was loose) yet it's still leaking, but I cant see where from!
The engine bay is covered in a fine mist of derv and only one (second one back) injector is wet. Any Ideas?

Mark

[ELAN+2]

thanks, i bet they aren't cheap!!