Fuel Range indicator becoming unreliable...

[BarboaR]

I have a 2008 Urban Runner with aprox 93K miles and have run out of gas four times in the last four months. The fuel range and gas gauge had been pretty accurate until recently. I used to go about 15 miles on 0, then it began to read positive numbers, then run out. First time it said 5 miles, then 8 miles, then 14 miles and then yesterday it read 24 miles left and ran out of gas. What made the difference this last time was the low fuel light never came on....Can this be fixed???? Thanks for your help!!!!

 

[03_4x4Runner]

Once your tank gets down to 1/4 get it filled up. This will keep the fuel pump cool and lasting longer. I do not see the point in running the tank down to the last quart.

 

[S p a r k y]

so your questioning why you run out of gas after the indicator says 0??

I wouldnt push it so far, treat it like yourself possibly, dont wait till its malnourished and on a death bed. When getting low, put gas in..

Reset the computer and you should be good.

 

[gm350reratliff]

Once your tank gets down to 1/4 get it filled up. This will keep the fuel pump cool and lasting longer. I do not see the point in running the tank down to the last quart.

I agree. There is no sense in running it that low. Keep it above a quarter tank. Plan to fill up at a quarter tank and treat the last quarter like a reserve in case the gas station is closed or your stuck in traffic.

 

[BlackWorksInc]

I have a 2008 Urban Runner with aprox 93K miles and have run out of gas four times in the last four months. The fuel range and gas gauge had been pretty accurate until recently. I used to go about 15 miles on 0, then it began to read positive numbers, then run out. First time it said 5 miles, then 8 miles, then 14 miles and then yesterday it read 24 miles left and ran out of gas. What made the difference this last time was the low fuel light never came on....Can this be fixed???? Thanks for your help!!!!

I recently discovered on my on how the fuel mileage is calculated by the computer, I wrote it up in this thread: http://www.toyota-4runner.org/4th-gen-t4rs/92104-how-increase-gas-mileage-4.html

But your problem has little to do with the computer, I would actually suspect that you have an issue with the fuel tank sender unit. There are two likely situations that are causing your problem.

-The first issue which is most likely is that the Fuel Gauge Sender Unit is malfunctioning are beginning to fail. It is a simple potentiometer that read a sweep of voltage on a resistance ramp, as the level changes, the arm on the sender sweeps across a different section with a different resistance value. If the unit has a dead spot or the sweep has built up different resistance it will skew your fuel reading.

-The second, less likely but still possible situation is that where you live and where you and the previous owners, if there were any, fueled up at gas stations that had some water in the fuel. Technically all fuel will have some water and it will settle at the bottom of the tank, if it collects enough it will displace the fuel and so your over all capacity for actual burnable fuel is decreased. This can be resolved by draining the tank and flushing it.

I am going to put my money on the first one, 93k is enough to possibly cause an issue, the second is also a possibility with your mileage but less likely. Unfortunately to replace the fuel sender you may have to drop the fuel tank, I don't remember if we make it easy to get to that component.