CVO 8/13/2010CHECK to see if the car has a fuel gauge fuse in the fuse box. The fuel gauge or the the gauge circuit may be at fault. First ,test the action of the fuel gauge with a fuel gauge tester.It is connected to the wire going to the fuel tank sending unit.When the tester is set on full, the fuel gauge should read full.If the gauge doesn't function, either the gauge or the gauge circuit is faulty.If the fuel gauge begins to work with the tester in place, the tank sending unit is probably bad.
CVO 8/14/2010This is the answer for the second question. Pinging is a metallic tapping or light knocking sound, usually when the engine accelerates under load. Pinging is caused by abnormal combustion and is normally caused by low octane fuel, carbon build up in the combustion chambers or engine overheating.