Richard, are you using the 250mm original sender or the 280mm one? Do you have the Maplins part number for the resistor you used, it would be handy? Also a photo of the installation sometime please. Sounds like a easy way of getting a bit more accuracy into the fuel contents system. With the 280mm sender I get 100% for a long time after filling, probably about 80 miles, then it drops to 0% after about 200 miles from filling.
