NO fix for Prius Gas Tank Filling Up Issues

[Silver 2008]

Well I guess this is as good a place as any to introduce myself. I just bought a 2008 Prius, broke it in and took it on its first 2,000 mile trip. I drove from Idaho to Lincoln, Nebraska, then up through the Black Hills of South Dakota and back to Idaho. It now has about 2,700 miles on it.

As with others in this thread, the last three fillups on my trip caused me a lot of headache. It started out by just being difficult. I had to pump in the gas very slowly to keep the nozzle from clicking off. On the next fillup, I did the same, but this time when I removed the nozzle, about a quart of fuel came squirting out. Yikes! Then the last fillup, It seemed to take the fuel a little better, then clicked off after a few gallons. I had driven almost 400 miles on that tank so I put more fuel in ... slowly. Then it started to run out on the ground. When I pulled the nozzle out, I lost about a half gallon. That hurts when it costs over 4 bucks a gallon. Not to mention the damage the fuel might cause to the paint and tire. It is possible that the slow filling allows you to overfill the tank, but I had to go slow to avoid the nozzle clicking off. Quite a dilemma.

It seems others (7 pages worth) are having the same issue.

One other thing (nothing to do with fuel), my Prius gets thrown about quite badly by stiff crosswinds. Is it just me? I can feel the wind in my other vehicles, but the Prius moves quite a bit more. Almost scary more.

I feel like I want to write a complete review of my experiences with the car. I have driven almost every condition imagineable (except snow). I am not all that impressed with the 9 speaker JBL system. Where's the subwoofer for heaven's sake. Also, another 12V outlet a little closer to the drivier's seat would be nice.

I also ran out of batteries up a very steep mountain pass in Wyoming. Then charged them to capacity and wasted some energy coming back down (the batteries were full). I will say the car is quite underpowered without assistance from the electric motor (when the battery was dead). I went to pass a slow moving motorhome, and ... nothing. I could not gain one mile per hour. The motor wound higher, but the speed remained the same. By contrast, however, I will say the car accelerates surprisingly well when there is power for the electric motor.

For the 2,000 mile trip, I averaged about 48 MPG, which is even better than I expected. I am very pleased about that. My best tank was 52 MPG!

Since I said some bad things about my Prius, I should balance that by saying I love my Prius. It is the car that will change all cars to come. It has an amazing level of intelligence and is full of "why don't all cars have this" features. It gets astounding fuel economy and requires almost nothing from the driver. It takes energy normally wasted as heat and stores it to get you up the next hill. And the touch screen controls and cupholders are cool.

Mike

[qbee42]

Your comments are not unique, and have been addressed many times here on PC. A google search on priuschat.com is your ticket to all of this information, if you are interested.

Tom

[mistymom]

I have had a unique experience with my gas tank/gas gauge. I was traveling and had gone about 300 miles (started off with full tank just pumped that morning) and had just moved down to 3 pips on my gas gauge. All of a sudden, I got the dreaded triangle and a couple of other warning lights and basically the car "died" on me on the highway. I was able to coast off at the next exit and into a DPS parking lot where I proceeded to call my Toyota. They referred me to the Toyota dealership close to where I was. Long story short, they towed me in and had a quick look, said my tank had run out of gas and reset everything (I was unaware of this) and recharged my battery and sent me on my way. I was baffled since I had only driven just under 300 miles and according to my gas gauge, previous driving and what I "should" have had left, I had 3 pips left or just around 150-200 miles left.

I took my car in to my dealership when I returned from my trip for a checkup and to investigate further what had happened. They told me that the other dealership had reset the codes so there was no way for them to read what might have happened. Since running out of gas (imagine that!) is not covered under warranty, I had to pay for other dealership service instead of warranty.

I had pumped a full tank of gas and knew how much I had put in. I should not have been out of gas. No way to prove it and has had me worried about running out of gas since then. The advice I was given was to just fill up every 200 miles. Sure, but that isn't why I purchased the Pruis. Not to mention, that could mean every other day going to the gas station. Again, not why I purchased my car.

I also have had 2 different instances where I tried to fill up the car on the last pip and it wouldn't accept over 1 gallon at the time.

At that aside, I love my car! Went to the dealership with my husband so he could get a Yaris to supplement his PT gas guzzler Cruiser and they kept wanting to buy mine back from me. Never in a million years!

[jima8]

I've had my 2008 Prius for about 3 months now and have filled it up 5 times now. Each of the 5 times I've had trouble with the pump clicking off after only filling it with 5 or 6 gallons of gas. I've waited until the gas gauge was down to the last bar and twice it was flashing. I talked with the dealer and was told it's "normal" and to try and put the gas in slower. I've tried that and tried different stations, but it always does the same thing. I've had 1 instance where it clicked off after the 1st gallon (it had only 1 bars of gas left on the gauge at the time).

It's really frustrating trying to get gas in this car. Aside from this annoyance, I love it. I guess I'm just really surprised that a Toyota vehicle would act this way, considering how well thought-out everything else on the car seems to be. About the only thing I've found that allows me to get anywhere close to 10 gallons in the tank is to barely have the nossle in the car and you can hear what sounds like air escaping around the nossle. The only problem with this is that the pump doesn't click off when it does reach full and it usually burps and pushes gas out.

[Shawn Clark]

Haven't had the opportunity to fill mine yet, so this thread has been educational. One thing I intend to do (and suggest to those who are having trouble) it to fill it with the fuel door on the up side of any slope (true flat landers need not worry about this.)

This is what I've always done with other vehicles as well, this way I get the max fill in and less variability. I look to see what pumps are open before I pull into a station, if my fill door is going to face downslope I keep going to the next station. (When I've had to fill on reverse slope the variability is usually north of 10%.) I do not try to top off (unless the pump kicked out early due to someone else's diddling with their nozzles--happens frequently enough.)

With a bladder and the potential for air pockets I want trapped air to have a natural high path out as the tank fills. That and letting the tank vent a little near the end seem to make sense.

Think about filling any bladder type container, you want the neck pointed vertical and the bladder "hanging" as freely as you can below. Any trapped air pockets must be able to vent upward during the fill.

Does anyone have detailed 3d drawings of the system for visualization? I'm accustomed to having detailed drawings for writing fill and bleed procedures. I hate guessing. I really need to know specifically what the geometry looks like before I determine what is the optimum fill angle.

I can see why cold weather could be a problem because the stiffer bladder might not expand as it should, but hot weather should only result in excess venting during the fill.

p.s. On the other end of the spectrum, I had a car that the dealer fouled up the fuel pump in (screwing with the wrong parts because they were incompetent.) When I made the mechanic reinstall it he must have positioned it differently as the tank became more sensitive to low fuel levels. Facing uphill, accelerating rapidly, or cornering sharply in one direction would starve the car for gas at about 1/8th tank. It still had plenty of gas in it, but I had to be careful how I parked it. (Never ran it out of gas.) About a year later the fuel pump went out...no doubt because of the idiots at the dealership messing with it and half a dozen other parts that were not the problem at the time.

[bedrock8x]

The genIII Prius will likely have a bladderless fuel tank like the TCH.
The bladder was used to minimize gas vapor emission during refueling when the gas cap is remove. The bladder eliminates air in the tank so gas vapor cannot accumulate.

The TCH uses a vacuum pump to purge the vapor in the tank when the gas cap opening button is push. It will take about a minute before gas cap cover will open.

The bladder is not a faulty design but it posts a problem with cold weather and overly sensitive gas nozzle shut down mechanism. There is no way for Toyota to fix this without retrofitting the Prius bladder gas tank with the TCH purging system.

Originally Posted by Shawn Clark

Haven't had the opportunity to fill mine yet, so this thread has been educational. One thing I intend to do (and suggest to those who are having trouble) it to fill it with the fuel door on the up side of any slope (true flat landers need not worry about this.)

This is what I've always done with other vehicles as well, this way I get the max fill in and less variability. I look to see what pumps are open before I pull into a station, if my fill door is going to face downslope I keep going to the next station. (When I've had to fill on reverse slope the variability is usually north of 10%.) I do not try to top off (unless the pump kicked out early due to someone else's diddling with their nozzles--happens frequently enough.)

With a bladder and the potential for air pockets I want trapped air to have a natural high path out as the tank fills. That and letting the tank vent a little near the end seem to make sense.

Think about filling any bladder type container, you want the neck pointed vertical and the bladder "hanging" as freely as you can below. Any trapped air pockets must be able to vent upward during the fill.

Does anyone have detailed 3d drawings of the system for visualization? I'm accustomed to having detailed drawings for writing fill and bleed procedures. I hate guessing. I really need to know specifically what the geometry looks like before I determine what is the optimum fill angle.

I can see why cold weather could be a problem because the stiffer bladder might not expand as it should, but hot weather should only result in excess venting during the fill.

p.s. On the other end of the spectrum, I had a car that the dealer fouled up the fuel pump in (screwing with the wrong parts because they were incompetent.) When I made the mechanic reinstall it he must have positioned it differently as the tank became more sensitive to low fuel levels. Facing uphill, accelerating rapidly, or cornering sharply in one direction would starve the car for gas at about 1/8th tank. It still had plenty of gas in it, but I had to be careful how I parked it. (Never ran it out of gas.) About a year later the fuel pump went out...no doubt because of the idiots at the dealership messing with it and half a dozen other parts that were not the problem at the time.

[Danny Hamilton]

Originally Posted by Shawn Clark

Does anyone have detailed 3d drawings of the system for visualization?

Try these.

http://www.autoshop101.com/forms/Hybrid13.pdf

the gas bladder: exposed!

Note that there is already a valve at the top center of the bladder, so you shouldn't need the filler neck to release trapped air.

[Shawn Clark]

Danny,

Thanks for that! This is even more complex than I hoped, so I'm going to have to cogitate on it for awhile. The system looks over-engineered to me and therefore prone to being fussy.

The vapor return/vent lines look too small, particularly with so many valves and fittings (hence the need for slow fill rates?) If liquid gets into some of those lines it could create a seal leg, etc. It's interesting that Toyota is relying on a nozzle seal to "improve bladder expansion with gas pump pressure."

I don't trust that center bladder vent to work as it is sitting atop a flexible bladder. I don't see enough elevation difference to be certain vapor won't become trapped elsewhere along a ridge or corner while liquid is forced into the central vent. During normal operation it should be okay for providing level. It probably won't give you an instantaneous level indication. (I'm assuming there is time averaging to level indication anyway, as in my other Toyota--it reads a little high after driving, and low on start up.) If it provided an instantaneous high level indication upon start up (but you know it took too little fuel) then you would know that the vent line to level reservoir and such had flooded stopping the fill.

So much for hoping for an easy answer...

[JHSmith]

Originally Posted by bedrock8x

The genIII Prius will likely have a bladderless fuel tank like the TCH.

The TCH uses a vacuum pump to purge the vapor in the tank when the gas cap opening button is push. It will take about a minute before gas cap cover will open.

Err,

The 2007 TCH the manual states that it may take UP TO 10 seconds for the fuel door to open, depending on the fuel tank internal pressure. Mine has always opened immediately.

If you have a TCH, does yours take about a minute to open? Or are you referring to the upcoming GEN III Prius?

[kazots]

I have a 2008 Prius and itI has only happened to me once. The tank was down to the last two pips and I could only put 3 gallons in, but I knew I could get home with that much gas. My solution is to go between 250 to 275 and fill up. It usually takes 5 gallons and works for me.