fuel gauge

Have a 2000 Suburban. Whenever I add fuel, the fuel gauge doesn't always register fuel. It may sit on empty, then bounce up to full, back to empty, back to full, etc. It may do this for 40 - 50 miles, then it works ok. And the needle doesn't slowly move up or down, its instantly up or down.
Any ideas?

Have a 2000 Suburban. Whenever I add fuel, the fuel gauge doesn't always register fuel. It may sit on empty, then bounce up to full, back to empty, back to full, etc. It may do this for 40 - 50 miles, then it works ok. And the needle doesn't slowly move up or down, its instantly up or down.
Any ideas?

I have that same problem on my 99 Silverado 4.8. Did you ever find the solution to that problem?

- J