Intermittent erratic fuel gauge

[Jdcline54]

Hey guys, I've got an 03 Eddie bauer with the 5.4...
Every so often, I have an issue with my fuel gauge moving up and down erraticly... all the way from empty to full no matter how much gas I have..along with that the miles to empty changes, tells me low fuel.
This happens whether I'm moving or sitting still. The last time it happend I had been parked for 5 mins with the engine idling...

I want to think sending unit, but what leads me away from that thought is the fact of how random this happens.. it sometimes goes years without doing it, then for no reason at all it starts acting up and usually only for a week or so, leaving me with not enough time to investigate. This time around it's been on and off for about a month, even causing me to run out of gas once. So I thought I would investigate..

So, any ideas?

 

[99WhiteC5Coupe]

I would use two treatments of Techron Fuel System cleaner (used to be called Techron Fuel System Cleaner PLUS) - according to label directions. Techron makes a 12 oz and 20 oz bottle - with a label for the number of gallons the cleaner treats. Often, auto parts stores will market the product as “buy one get one free”.

GM issued (yes, not Ford) TSB’s instruction its dealers to use the GM Fuel System Cleaner (made under license by Techron) to treat this fuel gauge symptom in the late 1990’2 - early 2000’s era.

I have used it in several of my my vehicles (including my 1999 Corvette) and it eliminated the erratic readings. They cleaner is designed to remove sulfur deposits that affect the sensor in the fuel tank.

In later years, the sensors were “hardened” to prevent the erratic readings.

 

[Jdcline54]

I'll give that a try thanks