Suden leak from bottom pipe on a P38

1999 P38
2.50 BMW

After doing a 400 mile stint Diesel started to drip from the 6th pipe ( next to the bulkhead) the pipes are all good and clean but this pipe is sudenly spraying fuel from around the pipe and nut at the Pump end, i took it of cleaned and it looks good and seems to fit well but i cannot stop it sraying out.
no worning lights on but the engine is rocking. I also cleaned the 6th injector
but that seems fine.
Any help please this has been two days of head banging
thanks
Doug

fit anew pipe and dont over tighten as this ruins sealing surfaces ,dont get any skin near sraying diesel its very dangerous to you if gets thru skin