Hi,
my Box is only driven in summer season, so it sits in the garage over the winter, and sometimes also in summer. 2014 i have driven it for 1.300 Km. This spring i noticed a very loud noise from the fuel pump. Went to the car parts shop and bought an injection cleaner which also cleans fuel lines and everything related. Worked great. Fuel pump is calm now.
Product was this:
LIQUI MOLY - Motorenöle, Additive, Autopflege - Produkte - Injection-Reiniger
Don't know if it's available in Cyprus
Regards, Markus