I have a 2002 2.0 fwd transit was driving fine then went to pick up my sons from school today , was sitting in van ticking over and it died as if it was going to cut out but didn't , I was low on fuel so switched off got boys went to get diesel and it kept cutting out like I had just turned key then it would re start no problem , cut out about 5 times in couple min , got fuel still same got home left it ticking over every so often it will die down as if to cut out then pick back up again

Any ideas thanks