A true NOS sender should make the correct ohms signal. Aftermarket reproduction senders work close enough at full and empty, just way off between. You can access that sender wire behind the left kick panel. Short it to ground briefly and see if that needle travels smooth and quick to 'F', then back to the 'E' again in the same manner when disconnected. Pauses and jumps in needle movement along with less than complete 'E' to 'F' travel are not good signs. If/when you open that fuel gauge to disable the limiter like most recommend, you'll get a look at what makes the needle move ( or not move ).
The thing is... at this point we know most the current coming from your limiter is traveling the temp gauge path of least resistance. Does it make enough current to properly heat up the fuel gauge at the same time? I don't have all the answers, just more questions. Does the temp' gauge go to 'H' when temp' sender is disconnected? Does the fuel gauge function any different when the temp' gauge is inop?
