New to the site and need help. I have a 1991 Oldsmobile Cutlass Calais sedan It has the 2.5L motor and auto trans. Anyways the gas gauge on my car is not correct, when you fill it up all the way the needle goes past full, and half tank is empty so have to fill it up at half. For a little while now it has been going through 20-40 bucks in gas a day. The gas gauge also floats when you give it gas. Oh and if this helps ive only ran out of gas twice and each time when I ran out, my car just shut off completely no warning. Any suggestions on what to check and stuff will help.

Sounds like you have a faulty sender in the tank.

What kind of mpg are you getting?, if your mileage sucks you need to go through a tune up and fault finding procedure.

When the tank is empty the pump will shut off to prevent damage, hence the sudden cutting out unlike a carburettor engine which will falter a little as the carb drains.

Roger.

Other than the comment about using 20-40 bucks a day in gas, it sounds like the fuel level sending unit in the gas tank needs to be replaced. A faulty fuel sender does not explain deterioration in fuel mileage.

How many miles per gallon are you getting?

20-40 bucks of gas a day doesn't make sense, unless you're driving that much.

The "sender" is the float in your gas tank that "sends" the level to the gauge on your dash. It'* normally integral to the fuel pump. So, you're going to have to replace the fuel pump, which can be a pain, or expensive (and therefore someone else'* pain).

The alternative it just to fill up more often and use your trip odometer to estimate your fuel usage. Of course, this risks getting stranded when you run out of gas.