1999 Gmc Jimmy

Here's the deal. Filled gas tank, wouldn't start, Battery was dead so new battery, shot of starter fluid ran fine un till next FILL up. Just does it on fills. Replaced relay, fuel filter, fuel pump. Someone suggested something ( gas guage sensor)telling engine was flooded. Where is this sensor? Someone also suggested reset button needed to be reset. Where is this? Don't tell me to look in owners manual, been there done that. Would welcome any suggestions. :banghead: