Inaccurate fuel gauge

I just bought a 2008 4Runner and discovered that the fuel gauge is not accurate. When it reads less than 1/4 it will only take 7.5 gallons and reads approx 2/3rds full. The gauge works just fine with no fluctuation, est miles to empty works as does the amber low fuel light. I feel like I am actually filling it up even thought the pump stops at 7.0 gallons every time and it also just reads 2/3rds full. It is a low mileage 0nly 66,000 miles and is really pristine otherwise.
Anybody else ever have this problem?

 

welcome

 

Tough one to troubleshoot. It could be one of several things.

Faulty fuel level sending unit would be my first guess. It's located in the fuel tank of course and includes the fuel pump. It requires dropping the fuel tank to service, so it's a bit of a bitch.

Other things could be the evap system preventing fuel from going into the tank. This would cause the filler to shut of quickly during fill ups though, so might not be an issue if the filler handle stays on. If the charcoal canister is plugged up, that might also prevent proper filling of the tank but I think that would also trigger various CELs.

 

Very likely the fuel sending unit, which is a known issue. on the other 4R forum should be helpful.

 

If you do have to drop the tank, cut yourself an access panel. Then future access is no problem. Before and after

 

Thank you guys for the suggestions. I wonder if it could be the actual dash panel fuel gauge being faulty? Like I said everything works as it should it just acts like it needs to be calibrated. Even though it has 66,000 miles, it it 16 years old