Gas Gauge Dead

If you have determined the sending unit is bad, and it's something you absolutely must have, then a replacement fuel tank is the solution. Available new for about $500 or you can find someone parting out a wrecked Gen 2 where the tank is still good.

 

I know someone who had limited success with freeing up a sticky gas gauge on a Hyundai by switching to top-tier gas (Chevron).

You might also try a gas additive that contains Polyetheramine (PEA) or a similar detergent, which is believed to be the same compound in some of the top-tier gas formulations.

Here are some options (product packaging or names may have changed) :

Any of the Techron products that comes with Concentrate Plus.






or Gumout with PEA (black hex in the lower right corner of the label)



Or a BG fuel system cleaner (which also has PEA) :



Though Berrymans does have other "gas additives" in their product line up that contain similar detergents like PEA, I would personally try Berrymans b12 - Chemtool (doesn't have PEA or similar, but is a quality product and a decent price point in the gallon size).


Please report back, letting us know what worked (if anything) and what didn't

 

You can try a fuel system cleaner, as pictured above.
But if the sending unit is bad? Then none of them will fix the problem.
But they are a relatively cheap gamble...might be worth rolling the dice once or twice.

Otherwise?
I'm afraid as pointed out, the solution is neither cheap nor simple.

 

Marvel mystery oil is supposed to be good for the fuel pump and sending unit. Heck anything is worth a try!

good suggestions above btw!

 

Ignorant new guy here but why do you have to replace the entire fuel tank?

 

Because the fuel sender and the fuel pump are inside the fuel bladder (Gen 2 only has the bladder) and the tank is therefore a sealed and non-serviceable part.

 

Holy crap what a horrible design.

 

Yup, overshadowed by the pressing need (at the time) to meet some CARB target or other. I guess they figured that they wouldn't fail. That is why it was only ever in the NA market. The rest of the world sighs with great relief.

Changing the fuel pump on my Prius is just like how you would do it on a Corolla/Matrix. Quick and easy.

 

Why is it easy on yours? Yours is a 2006 right?

 

Because he lives in New Zealand and Gen 2 Prius gas tanks there don't have bladders. They don't have what is called the thermos tank either. A little research around here goes a long way.

 

This illustrates the difference between premature clicking off and "topping off".

To avoid the former, you need to hold the filler nozzle at 70º - 90º to the left or right, or even at the 12 o'clock position (coming down from above down into the tank). Secondly, only place the nozzle just far enough in the filler neck to do the job without spilling fuel, and then a bit more. Just find the method that works for you.

Even without the bladder (as it is in all Prius outside NA), you still have the problem of premature clicking off. It is the case that without the bladder, you are more confident to continue to fill when the amount of fuel that goes in the tank does not make sense. I have never not been able to get the appropriate quantity of fuel in. With a fuel tank bladder (and even without), YMMV.

 

LOL So does a quick question.

 

touché

 

Is the problem still resolved?