at my wits end

Hello,
Can anybody out there please help me with my defender 110, it keeps cutting out? it is a P reg. it suddenly cuts out as I'm driving along, I pull over the best I can and leave it for 5mins then it will start up again, this has been going on and off for years, I can go 6 months without it happening and then it can start happening again 2 or 3 times a week, does anyone know if there is a filter on the pipe in the fuel tank?

year, engine? what checks have you done, replaced parts?

checks ??? possibly 6 month ago when it last happened