1999 silverado
soon after starting the gas reading swings high then low causing low fuel light to come on.
but after 10 seconds itll swing to where it should be?
level is correct btw
also all connections from the gage to the tank are tight and corrosion free.

It's not possessed, you just need a new sending unit. Sending unit & fuel pump are one unit and is located inside the gas tank. Go with OEM unit - runs ~$300.