2000 with a brand new dealer installed complete pump broke down on vacation ( over $1200.00 ) 15 months ago . About 2 weeks ago it started to idle rough in the mornings and would be fine driving after warmed up .

Thursday driving down the highway all of a sudden the gauge drops past empty and the low fuel light comes on . This happens at even after being topeed off or any amount of fuel in the tank . At any moment it will work correctly again or drop again . All other gauges in the panel work correctly .

It would appear that the fuel level portion of the tank unit is failing ?
Any suggestions ?
Thanks for your help .

 

Welcome to the forum.

First thing I'd try for the rough idle would be to run a couple of bottles of Techron thru it.

For the fuel gauge, your guess is probably right since it triggers the low fuel lite although it's possibly a bad connection since it seems intermittent.

 

You have to take a look at where your connections of the fuel tank and wiring harness is and see if there is a bent tab or pinched wire in there. You may have to open the tank and see what it looks like. Usually the dealer would replace the sending unit and the pump together since they come as one piece. But in some instances it may be easier or more available just to replace the pump. Which could mean aftermarket pump with different connectors.

Or could be bad Instrument cluster, does the gauge sweep when you start the car? If so, its good, if not, its not.

 

I'm thinking along the same lines as RacerX, I would suspect a possible loose or poor connection at the fuel pump connector or possibly they pinched some wires while re-installing the tank..
Also I second 73shark suggestion on the Techron... if a couple of bottles in a tank of gas show improvement in the idle you might consider servicing the injectors

 

Thanks for the help !!

The gauge does sweep when started . I will try the techron and see if I can find something at the conection .