I am doing a vivaro at the moment where the hand primer is sucked flat and cutting out,had it on the ramp today and the pipe has a very bad kink at the tank unit,how it has come to be like that I do not know,i think it has damaged the hand primer as there is no resistance there when you try and prime the filter and have a new pipe/primer on order so will have to see how it pans out,I would also check your air filter,if it is damp then your engine may have swallowed some water and engines don`t like that and can cause severe internal damage often resulting in a new engine required.I think I would first try and see what issues are with your fuel system.
cdc
January 2013