Hi I have a fiesta mk4 with a 1.7 16v zetec pUma engine, when I am driving along its spot on but say I am slowing down for a junction I drop into 2nd let the clutch up a bit for some engine braking then I put the clutch back in as I need to go into first the revs will drop to zero and engine cuts out, flick of the key and it fires straight up and drive off again, it only does this every now and again about twice in a days worth of driving ? I am totally confused, been told it could be fuel filter or vacuum hose leak ? Someone please help me !? Thanks, Adam.