toyota gas gauges

The only time I have ever heard of a fuel filter in a Toyota clogged with black sediment like you are describing is if someone used a lot of fuel treatment or fuel injector cleaner. That stuff dissolves the rubber parts of fuel lines and can clog filters. If it happened in another vehicle and you did not use fuel injector cleaner, kept the tank full, etc, then perhaps that vehicle is not a durable as Toyota's.

Not aware of any additive in gas. Refineries were required to add something called MTBE ???? that had the reputation as being bad and discontinued since it also has been linked to cancer

Okay, this brings up something I heard years ago. Isn't it bad for your car to let the gas get really low? Or is that just a myth?

Guys?

Natalie

how is the sediment flushed out? those tanker trucks put gas in those tanks never taking any out. in some states they hook up 2 hoses but that is to push the vapors into the trailers tanks and not release them into the air. but can tell you one thing. you should never buy gas when a tanker truck is unloading, this does stir up those sediments and they can be pumped into your car. of course one could have left 3 minutes before you got there and you wouldn't know. those pick up tubes in the grown tanks are 2 inches above the bottom of the tanks. drove a tanker truck back in the 70s is how i know all of this good stuff. lol. they do check for water sometimes by putting a paste on the stick they put in the tanks to measure how much is in the tanks. turns another color if water is in the tanks.

I agree with "First" and "Second", but I don't understand the logic behind "Third".

While I agree that engines are meant to operate on fuel not water, I don't understand how the level of fuel in the tank has any effect on the fuel pickup ingesting water.

Water is heavier than fuel, so the water will collect at the bottom of the tank.

The fuel pickup is attached very near the bottom of the tank. It is attached there and does not float or move around, so if there is sufficient water in the bottom of the tank, the pickup will suck it up.

The fuel in the tank sloshes around, but it will not absorb the water. The fuel and water may mix temporarily while the tank is being shaken (driving will shake it). A cup of water in 20 gallons of fuel is a very small percentage (0.3125%). A cup of water in 2 gallons is a lot higher percentage (3.125%). Maybe that is the logic I missed.

Thanks for helping me figure this out!

When you have an air volume with a moisture content that moisture may turn to condensate or water when cooled.

So eliminate the air volume - is the thought. j

The additives put in by the refineries would not hurt the fuel system. The additives I was speaking about were added by the customers.

Just avoid adding anything yourself to the fuel tank besides fuel and you should be OK.

You should not let the gas get really low. Besides the possibility of running out of fuel, the extra air in the tank can contain moisture, which can condense in the tank. Also, if you run the fuel pump dry, it can burn out because it relies on the gas flowing through it to cool it and to lubricate it. Running on a low tank runs the risk of the fuel pump sucking air when the gas sloshes around, which can cause drivability problems.

You explained it a lot better than I would have!

The sediment gets flushed out through the process you described. The process of filling the underground tanks gets everything stirred up, and it gets pumped into customers' tanks. A little bit of sediment spread out over

"Ray O" ...

Ah - thanks.

I'm too chicken to let it go much less than a quarter tank, anyway. Hubby had us riding on 'E' going through rural North Carolina...*rural* NC! I gave him hell.

Natalie

A quarter tank is a good time to fill up, especially in rural NC!

Especially when you're DWB...

Natalie

If the tank is vaguely wedge or trapezoidal shaped, with the pointy end down, there is a lot more cross-section volume at the top of the tank as compared with the bottom.

Same effect is easily visualized with the Classic Coca-Cola fountain glass - large on the top, and necks down sharply toward the bottom. If you drink it at a constant rate, the level will go faster as you get closer to the bottom because of the smaller cross section.

They could wind the resistor in the gauge sender non-linear to match the volume - but they would need a custom sender for every car model, and that would be spendy. They just use a linear one across all models, and some cars odd shaped tanks will just make it read funky.

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No myth, though it varies with pump designs.

Constantly running dry is hard on the in-tank electric fuel pump, because it isn't submerged in cooling fluid (the gasoline). And when it runs totally dry the pump surfaces are running metal on metal. Keep it above 1/4 tank (1/8 at the outside) and the pump is much happier.

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On 07 Jun 2006, the world was enlightened by Wickeddoll®'s opinion about...

Something I'm sure, after all these years of marriage, he's used to... :O

kevstartsarunnin'

No argument from me on that one!

In a related vein:

During the course of one winter I spent in an exceptionally cold climate, I had several experiences of water in gasoline causing drivability problems in my '82 pickup (22R). I could actually see a layer of water underneath the gasoline in my fuel filter, stratified like oil and vinegar in a glass measuring cup.

My theory was that because of the low temperatures, the water had condensed from the air in partially-full gas station underground tanks. I bought most of my gas from a busy discount station, so I figure their tanks spent a lot of time only partially full.

Geoff

I and a coworker got lost one January night in the boonies around Durham. We were on a major highway, but the distances between towns (and freeway exits) were so vast that it was downright dis- concerting.

Being from California, I'm accustomed to only driving so far, even in rural areas, before the glow of a nearby town becomes visible and helps give me an idea of where I am. But thanks to that vast, endless darkness, this was more like a translunar injection than a freeway drive. Yeesh. It's easy to understand how people in places like that think they see stuff like Mothman or the Jersey Devil.

Geoff