Cheap Sam's gas I buy, probably algae.... I noticed it right away at fill up. Gauge just didn't spring up to full+ like normal. Worked normal the next day. Going to try doing one side only first and try to bend the contact in a hair for more pressure, but not til the weekend after I run the tank down. I think it's just one side that is acting up, readings averaged between the two senders. Just a thought, but why does it need 2 senders anyway? Suppose one is for the gauge and the other for DTE? DTE reads as expected.