Any idea's?

Got a 1.4 16v Fabia X reg, which appears to have developed and intermittent flat spot when accelerating in first gear. It jumps and stutters for a couple of seconds, then kicks in and is ok. It drives ok in the higher gears. As I say this is intermittent at the moment and I have no warning lights.

Recently filled up in a BP garage,as in 20 miles ago, wondering about dirty fuel?

Would appreciate and suggestions. Car has got 6 months warranty left

cheers,

Sam

might be dodgey fuel i suppose, but it's more likely to be a dirty map sensor