If I keep the tank full everything works fine. But as soon as I let it go down to about half it will suddenly drive as if fuel isn't getting through properly, it's just as if I've taken my foot off of the throttle for a second then put it back on. Hence kangaroo petrol

If I stop and switch it off and restart then it might drive for miles perfectly or it might happen all over again.

My van is actually a 2008 Piaggio Porter panel van. It's exactly the same as the Hijet I had before it.

I'm wondering if it could be the petrol pump which I think is inside the fuel tank.

Any ideas or advice welcome

Thanks