Fuel gauge shows full, even tank is empty. - 1992 Honda Civic

Pull the wire off fuel tank to the sender unit earth it out with ignition on.The fuel gauge should go to full slow even motion if it does replace unit in petrol tank.If it doest move you need new fuel gauge.Also before any of this i sumise you have checked fuse

sounds like you may have a bad fuel level sender problem. as for the check engine light coming on and storing a fault code that is a separate issue.

It could be the sending unit in the tank or the gauge on the dash. A mechanic would test the signal coming from the sending unit to verify.

If the trouble with the gauge started after you worked on it then you likely damaged or created a restriction to the movement of the sending unit. You will have to remove the tank and double-check your work.

the gas is regulated from the switching valve you control off the dash. Check the valve to hear it switch
have a friend help you do this. it will be located under the truck between the two tanks. You may have a faultly valve or switch rattling inside changing the tanks setting also while driving which will be hard to tell

hi, yeh it could possibly be a fuse maybe? sometimes the fuse can protect more than one circuit. i would start there.

sounds like the float is either got a hole in it and is full of fuel, or the whole float assembly is seized in the empty position.
was the car left for 5 weeks empty of fuel?

Usually if the gas gage does not work yes it is true it may be the sensor if it is electronicly controlled. the sncor will more than likley be in the tank. here is how to remove your gas tank.

1. Before servicing the vehicle, refer to the precautions section.
   
2. Relieve fuel system pressure.
   
3. Drain the fuel tank.
   
4. Remove or disconnect the following:
   
   • Negative battery cable
     
   • Fuel filler and vent hoses
     
   • Fuel tank skid plate
     
   • Fuel tank wiring connectors
     
   • Fuel supply and return lines
     
   • Fuel tank
     
   • Fuel pump assembly
     Fuel pump assembly mounting
     

To install:

1. Install or connect the following:
   
   • Fuel pump assembly
     
   • Fuel tank. Tighten the bolts to 27 ft. lbs. (36 Nm).
     
   • Fuel supply and return lines
     
   • Fuel tank wiring connectors
     
   • Fuel tank skid plate
     
   • Fuel filler and vent hoses
     
   • Negative battery cable
     
2. Start the engine and check for leaks.
   

Sounds like the Fuel sender unit in the fuel tank needs replacing however you may want to check that the electrical plugs are contacting properly,Check that the gauge is working by putting a piece of wire from the sender unit wire to the chassis,at the fuel tank sender unit plug,Turn ignition on while watching gauge if it moves toward fill turn ignition off and remove wire to chassis.If gauge moves it means from the fuel tank to fuel gauge is intact and not your problem.

You don;t say whether the fuel gauge is reading accurately, or whether it's always on empty. If the gauge is always showing empty, it's most likely a problem with the sending unit in the fuel tank. Check the resistance across the two terminals of the sending unit.

On a C900, the fuel sender level unit is separate from the fuel pump and located on the right side top of the tank, accessible by removing the trunk floor lift up panel (the pump is located on the left side top of the tank.
Possible problems are: electrical line off or broken, float not working (it's fairly delicate); or gauge not working.

Test the resistance of the sending unit with the lines disconnected, the resistance should be 2.6 to 3.8 ohms full tank, 63.3 to 67.5 ohms empty tank; and test for voltage across the top of the sender unit, if no voltage, that's likely the problem!

If the gauge is otherwise reading accurately (showing 'full' for a full tank, etc) then the problem is likely a gauge malfunction and can be simply replaced.

Good luck!

Saabreur