i have a `1972 olds mobile cutlass s and have a gas tank issue i cant tell how much gas i have what would be the typical reason and can i fix them so that it works? i keep running out of gas because i dont know how much i have left..

 

First check the tank's sending unit ground that goes to the floor pan above the rear end (axel).

 

Fill the tank and write down the mileage then fill it again and determine MPG and then go by how many miles you can go before you need gas.
Run out of gas all the time? You ever put enough gas in to make the gauge move??
A dollars woof of Ethyl ain't very much anymore?
Just kidding.

Check the ground as recommended, connections. You can search past posts, plenty of old ones on gas gauge problems. If that all checks out it's probably the tank sending unit and that means dropping the fuel tank, not that hard. You just need hand tools, common sense, and a CSM.
The 1972 Oldsmobile Chassis Service Manual/bible will tell you how to diagnose it and how to fix it. The CSM is indispensable, no car should be without one.