Gas Gauge

When i fill my buick up the gas guage only stays at quarter tank won't get any more "full". But it will lower, any suggestions on how to fix it?

Drop the gas tank down, and change the sensor. It may just be stuck, but you will have to check it out to find out why.

I had a gas gauge sensor problem in a 97 Lesabre. It would read erratically though, sometimes low, sometimes high (never accurate). A new sensor is about $350 for a 97 Lesabre. It only comes with a fuel pump attached. Put in a salvaged one for $75. It didn't work, so put in another salvaged one and it worked that time. Sounds like if yours is sticking, maybe you can get it going again; depends on what type it is I guess. The sensor in the tank is a variable resistor that reads between 0 and 240 (240 is full) ohms (at least for the 97). It must not be reading at the higher levels. They are kind of cheesy, junky plastic deals, so it is not surprising that they fail. I read that there was a certain brand of gasoline that ruined a lot of them. I don't recall right off hand which brand it was. Many GM fuel sensors read between 0 and 90 ohms, but this one was different.