T5misbehaving

[Taff - t5]

Everytime I put fuel in my 850 t5 it plays up
It won"t idle as it should seems to idle to fast and sometimes cuts out.
Next day cars running as it should idles at 850rpm and runs ok.
Anyone got any idea why this happens as I"m completely baffled.

[AlanG]

When I first had mine it would start and cut after re-fueling. Turned out to be blocked tank breather. Do you have a vacuum release sound when you remove the filler cap? Just a thought....