300tdi issue

Had a problem with the 300tdi tonight - after a 30min motorway run and a short run through a little village I pulled up at the lights and the engine would seem to have been missing on a cylinder.

As soon as I lifted the rev's a touch it went back to normal its not done this before and its running on pure derv with new filter, the fuel lines were also recently replaced.

I am going to say maybe the lift pump, at low revs the Bosch unit can't suck enough to keep it running well? When the 300tdi Disco did it, it only caused issues above 3000. There is also a clicking noise and I am thinking along the lines of thats the little bar pinging back and forth!

Its done about 130,000miles, pulls well, no smoke runs at normal temp...

So ideas please chaps!

check the high pressure injector lines are tight/not leaking.

Aye they were OK boydy, as it was happening I got the lamp out and had a good look about.

Also, it did clear after about 3/4minutes, it could be a blocked/sticky injector I guess. They probably need reconditioned.