Hi, my mk1 Focus 1.8 zetec 2004 has started juddering when accelerating. It only seems to happen after its been running for about half hour and is warm. When I run the car first thing it runs fine but once warm that's when the juddering starts. It normally happens when pulling off from lights for example. It seems to happen in 2nd and 3rd gear around 1500 revs up to 3000 revs

I've been reading around and it seems that it could be Fuel filter related problem, I was wondering if anyone else has had the problem or could offer advice on it.

Thanks.