gas guage not working
First check the supply voltage
also GM had a problem with some gas companies in which there was not enough detergent in the fuel so a film built up in the sending unit, and some were just unservicable. Believe it or not because i didnt they told their customers to use their GM fuel cleaning solution and it may take two full tanks or over 1000miles before u notice a diff.
On some cars it worked, and some not so lucky.


