Gas gauge
The power path is switched ignition to the cluster through the cluster PC board connector, to the IVR, through the PC board to the gauge stud, through the gauge and out the sender stud, back to the PC connector, through the harness to the left kick panel connector/ rear harness, back to the sender, through the sender resistance to the sender "shell" and to ground through the nonsense jumper at the fuel suction line grounding clip
Any one of those points can have a problem
Does the temp gauge seem to work normally? If so, that would eliminated some of the cluster problems.
The fuel gauge studs can be loose, correded at the pc board / nuts and the gauge can be bad. you could have a poor harness connector problem, or at the sender or a sender problem itself, or the ground could be poor
To start checking "rough and quick" jumper the sender wire to a known good ground at the tank. Turn the key to "run" the gauge should peg. DO NOT leave the power on longer than necessary. You can get an idea of gauge accuracy by substituting known resistance at the sender to ground and see what the gauge does. This is an old photo someone doctored from a factory or factory "like" gauge tester unit
The power path is switched ignition to the cluster through the cluster PC board connector, to the IVR, through the PC board to the gauge stud, through the gauge and out the sender stud, back to the PC connector, through the harness to the left kick panel connector/ rear harness, back to the sender, through the sender resistance to the sender "shell" and to ground through the nonsense jumper at the fuel suction line grounding clip
Any one of those points can have a problem
Does the temp gauge seem to work normally? If so, that would eliminated some of the cluster problems.
The fuel gauge studs can be loose, correded at the pc board / nuts and the gauge can be bad. you could have a poor harness connector problem, or at the sender or a sender problem itself, or the ground could be poor
To start checking "rough and quick" jumper the sender wire to a known good ground at the tank. Turn the key to "run" the gauge should peg. DO NOT leave the power on longer than necessary. You can get an idea of gauge accuracy by substituting known resistance at the sender to ground and see what the gauge does. This is an old photo someone doctored from a factory or factory "like" gauge tester unit
