FUEL SYSTEM TECH TIPS
In most cases the fuel float, part #COAZ-9202-B, is the cause for the gauge not working. It fills up with gasoline and sinks to the bottom of the tank. Your fuel gauge cannot read the fuel level if the float and lever are stuck at the bottom of the tank.
The second most common reason is the fuel sending unit. In either case you must pull the fuel sending unit out to see. Make sure you have less then ¼ tank of gas or you will be wearing the rest.
If your gas tank is rusty throw it away: Go buy a good one.
If you have a rusty tank then you also have a rusty fuel sending unit and a rusty fuel filler tube.
Change the filler tube with the tank.
You might be able to clean or fix the sending unit.
Experience says that you cannot fix a rusty gas tank. Putting that liner stuff in them is only a very temporary band aid. It will not last. Again, go buy another tank.
Always change the fuel filter when you do oil changes. You will need a fuel filter wrench. It looks like a small oil filter wrench. Take notice how much debris is in the can. This will tell you a lot about the condition of the fuel tank and fuel lines.
Be careful jacking your car up on the drivers side. The fuel line and brake line are under the rocker panel and can get crushed because some mechanic was not careful.
If your lines are already crushed then you should replace them.
This could be the cause for fuel starvation or a brake hydraulic problem.