It's more than likely the sending unit. Mine did the same. Then it read full empty. Then intermittent, ect..
If it isnt acting right it is going south on you. The only problem is. The sending unit isnt avail by its self. You have to buy the pump & everything. I think it was like $150 form NAPA( not sure what stores you have up there).
I just replaced it as a unit( didnt swap out the pumps) & have my spare Walbro from the old unit, just incase.It's a plastic tank BTW, so I dont think rust will be an issue.
BTW, mine was also leaking at the base gasket on the SU, They tried to replace it before( this was before I got it) but twisted the gasket( rubber & VERY easy to screw up).
So be very careful,if & when you do it.
It took me about 4 hours from start to finish. The dealer said it was going to be about $700. I did it for the cost of the pump & an afternoon, with common hand tools.
