C280 sending unit
I still donít believe it but running through 3 full tanks of fuel seems to have resolved the sending unit problem. Looking at my receipts my problem started following a fill up at Wal-Mart (10 % ethanol). I ran the tank low each subsequent time and filled up with 94 octane as usual at the local Mobil/ Exxon station. The gauge function became steadier with each fill-up and now it is rock steady.