Charcoal canister repeatedly filled with gas - Toyota Nation Forum : Toyota Car and Truck Forums
Camry & Solara Lounge Discussion area for every generation of Toyota's family car, the Toyota Camry. Lexus ES250/300 owners welcome! Topics of discussion range from fuel economy, safety, modifications, performance and more.

Reply
 
LinkBack Thread Tools Display Modes
#1 Old 12-29-2004, 06:52 PM
New TN User
 
Join Date: Dec 2002
Location: Indiana
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
(Thread Starter)
Charcoal canister repeatedly filled with gas

I have read the posts on this forum about the leaking gas cap and the Vacuum Switching Valve.
I have read many complaints from Camry owners ('98-2001 mostly) on another forum about these problems and also sulfur odor from the exhaust, which I have had almost constantly. There is much denial and obfuscation from Toyota, according to what I have read.

My problem is a charcoal canister contaminated with gas. I am now on my third canister at about 50K miles ('98 Camry LE 4 cyl.). I have never had a check engine light or other warning light come on. The dealership has never shared any information about stored computer codes for this problem.

Timeline:
Bought the car in spring of 2001, 28K miles. Did not drive it much for the first 1 1/2 years due to health problems. I always smelled sulfur upon acceleration. The dealership said that odor is caused by regular gas and to use mid-grade. Mid-grade did not solve the problem.

Started driving it regularly, mostly on a regular tip of 180 miles twice a month and some around town, in fall of 2002. Sulfur odor persisted. Mileage on trips varied wildly from 28 to 42 mpg. Average of 10 trips came out to 32 mpg.

August, 2004, it suddenly started to hesitate and buck. Sometimes it would recover for awhile, sometimes it would die. Was towed to dealership. Diagnosis was "47865 charcoal canister contaminated with fuel, causing rough idle when purge V.S.V. is on. replaced charcoal canister". Total cost $485.11. I had a long conversation with the Toyota Master Technician. He said that over-filling the gas tank is the main cause of a flooded canister. I described my long standing fillup technique, and he said that I was doing it right. He said to never keep on adding gas after the nozzle clicks off the first time. He also said that a BALL VALVE in the TANK could cause a flooded canister, but it is unlikely. The sulfur odor went away with the new canister until November. I continued to set the nozzle on the low flow position and did not add any gas after the nozzle switched off. I did not go to the station that I ususlly went to, and varied the pumps that I used at the stations I used, to reduce the chance of having a malfunctioning nozzle over-fill the tank. The gas mileage on trips became less variable.

December 2004, the hesitation and bucking returned. Another tow to the dealership. Diagnosis was "50059 ck out/charcoal canister is full of fuel/ replaced the canister. is the customer over fuel the tank". The service advisor insinuated that I must be over-filling the tank. He said he contacted Toyota and was told that the ONLY cause of a flooded canister is over-filling. I had already explained that I had been very careful to not over-fill the tank. I was told that the part and labor are covered under the Toyota 1 year warranty for new parts. Great, but I am the one who is going to be injured or killed if this things dies again in traffic.
I have been so lucky the first two times, since it happened very near my house.

And, the next flooded canister will not be fixed for free, I am sure. The service advisor told me to NEVER fill the tank again, and this would prevent another flooded canister. I am very skeptical about this "solution" to the problem.

In addition, I have contacted pump manufacturers and nozzle manufacturers. A Gilbarco representative (who drives a '97 Camry) said he never heard of such a thing happening to a canister. He said he fills his tank "as much as possible" and never had a flooded canister. A Husky nozzle representative told me that I am not doing anything wrong which would over-fill the gas tank. His '98 Camry has 125K miles and he just fills it up like normal people do.

Does anyone on the forum know about this valve in the gas tank, and if it should be replaced? Is a flooded canister something that would be caused by a bad VSV or another bad component in the emissions system? Would a leaking gas cap and under-pressurized fuel system cause a flooded canister? Conversely, would an over-pressurized fuel system cause this? What would cause over-pressurization?

There are millions of these cars on the road. A search of this forum of "canister flooded" and "canister contaminated" brought up nothing. Any of your experience or well-educated opinions would be appreciated.
Lokamaya is offline  
Sponsored Links
Advertisement
 
#2 Old 12-29-2004, 09:25 PM
Official TN Member
 
Join Date: Dec 2003
Location: pa
Posts: 53
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
i used to fill my 87 camry up to the very top after it clicked many times and never had this type of problem

1989 camry ghetto sled
dallison is offline  
#3 Old 12-29-2004, 09:50 PM
JUST RE ENGINEER IT
 
fredk's Avatar
 
Join Date: Nov 2004
Location: Tooele UT.
Posts: 2,983
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 8 Times in 4 Posts
iTrader Score: 0 reviews
WOW lots of mis information here. First thing, the smell has nothing to do with octane rating, it is usually associated with running rich. And here is a lesson on gas tank design, the filler pipe does not come into the tank at the top, there is a built in air space above the filler neck level that cant be filled with gas unless the car is upside down, or you have air escaping out the vent line or where the senders bolt in or a hole in the tank in this area, and this is where the vent line to the charcoal canister comes from. Now you know why they are saying you are somehow getting this area filled with gas but its nearly impossible, since the gas will run out the neck before this area gets filled. NOW here is what happens to the canister system, these stupid things came out in the 70s when the epa said cars cant vent the gas tanks into the air, now we put gas caps on that only let air into the tank and a vent line to a holding tank that engine vacuum sucks clean usually right after start up. This VSV is a electric vacuum valve ahead of this canister in the engines vacuum line that lets the vacuum clean out the canister only at certain times and is controlled by the ecu nowadays, it used to be hooked to the choke wiring on a car with a carb. NOW if the VSV sticks on, it will suck the tank until the check valve in the cap releases or it just sucks the tank flat and the gas comes up into the vent tube, fills the canister and after it fills, it starts getting sucked into the motor and starts running rich

fredk is offline  
#4 Old 12-29-2004, 10:19 PM
New TN User
 
Join Date: Dec 2002
Location: Indiana
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
(Thread Starter)
Thanks, Fred. Very helpful. So, the problem can be a faulty Vacuum Switching Valve.

I have learned on this forum that this valve was re-designed because of failures. My Camry likely has the original one.

So that I understand fully, when you say that the VSV is "stuck on", do you mean stuck open or stuck closed? Or, is it a bidirectional valve which is always open but switches to allow flow of vapor or gas in either one direction or the other direction?

Since I have to spoon feed this information to the service department (or, maybe to an independent shop), a more detailed expnanation for the lay person (me) would be helpful.

Your answer also explains why the new canister solved the sulfur odor for a short time, until it became contaminated with gas again.
Lokamaya is offline  
#5 Old 12-29-2004, 10:37 PM
JUST RE ENGINEER IT
 
fredk's Avatar
 
Join Date: Nov 2004
Location: Tooele UT.
Posts: 2,983
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 8 Times in 4 Posts
iTrader Score: 0 reviews
stuck open, or the ecu is keeping it open

fredk is offline  
#6 Old 12-29-2004, 10:38 PM
JUST RE ENGINEER IT
 
fredk's Avatar
 
Join Date: Nov 2004
Location: Tooele UT.
Posts: 2,983
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 8 Times in 4 Posts
iTrader Score: 0 reviews
just pop the vacuum line off the canister andplug it off

fredk is offline  
#7 Old 12-30-2004, 12:10 PM
Official TN Member
 
Join Date: Jul 2003
Location: MOntreal
Posts: 148
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
Check this site for charcoal can. info.

http://www.autoshop101.com/forms/h62.pdf
burchard is offline  
#8 Old 12-30-2004, 12:12 PM
Turbos = Witchcraft
 
Ne0z31's Avatar
 
Join Date: Jul 2004
Location: Bloomington, MN
Posts: 730
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 2 Times in 2 Posts
iTrader Score: 0 reviews
i removed mine... never a problem

Ne0z31 is offline  
#9 Old 12-30-2004, 02:57 PM
New TN User
 
Join Date: Dec 2002
Location: Indiana
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
(Thread Starter)
Thanks, burchard, for the link to the Toyota .pdf file on emissions systems. It is a big help.

I assume that this '98 4 cylinder has an ECM controlled emissions system, and fredk indicates that it does. Is fredk correct? (just looking for two sources, like a good reporter, fred)
Lokamaya is offline  
#10 Old 12-30-2004, 03:23 PM
Know God. Work Hard.
 
Your Uncle Moe's Avatar
 
Join Date: Dec 2003
Location: Queens - NYC
Posts: 2,183
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 5
Thanked 5 Times in 4 Posts
iTrader Score: 1 reviews
Unfortunetly the sulphur smell is a very common problem. With me it happens only upon hard acceleration and I was told that it was unburned fuel and vapors coming from the exhaust.

97 4Runner & 90 Eagle Talon TSI (AWD TURBO)

"Love is all you need to know and all you need to know is love is all you need to know."
Your Uncle Moe is offline  
#11 Old 12-30-2004, 04:50 PM
New TN User
 
Join Date: Dec 2002
Location: Indiana
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
(Thread Starter)
I had a fruitful conversation with the dealership owner and his service manager, who was unaware of the Toyota 150k, 14 year extended warranty on the emissions system. I did confirm with Toyota that my car is covered. The helpful Toyota rep Kim is sending me a copy of my warranty.
I told her that I didn't get a letter and found out about this from other owners.

The service manager described the very complicated details of getting this completely closed system to work right with a volatile and easily expanded and contracted (by temperature change) liquid (gasoline). It is not a simple thing, and all the manufacturers are having troubles.

He admitted that I am doing nothing wrong by filling my tank like everybody else does, and he is going to look into the possible causes of a flooded canister other than blaming it on me. He volunteered to say it is not my fault. He gave me permission to fill my tank like he and the rest of the world does. He said that maybe the warranty will pay for a new canister every 3-4 months, whenever I start smelling the sulfur odor again. He said that the odor comes from richness of the fuel/air mixture (causing unburned and underburned fuel) when the canister starts to have liquid gas in it, and that the computer is not designed to recognize this problem, so there is no warning light and no code. He speculated that the computer can compensate (because it mistakes this problem for a non-problem that is within the tolerances of its fuel/air mixing operating range) and keeps the engine running (with the sulfurized exhaust gas) up to the point when the amount of liquid gas in the canister reaches a critical amount. After that point, the computer can't compensate and then the bucking and dying happens. Another possibility is that the valves, which are not supposed to touch liquid gas, become deteriorated by their contact with the gas and this could be part of what is happening. I believe that he meant that they are functioning mechanically and electrically but they are not able to do their jobs, hence no code. He is going to get the details of the warranty and I guess ask how many canisters I can get and how often.

I went over my list of possible causes of the canister filling with gas that should be considered. Regarding the purge valve and some other valves (none of which are officially called VSV by Toyota), he said that he thinks these are included on the canister assembly, so they may have been replaced in August. Obviously, they did not solve the problem. He is going to trace the production numbers of the August canister and my new December canister and find out if the December one has upgraded parts. He is going to do some acutal thinking and asking and talking to his technicians about this and then call me back with some answers or some plan of what to do for a further diagnosis.

The 800 pound gorilla in this whole emissions system constellation of problems gets down to the basic physics of a completely closed system containing a liquid which expands when heated. Where will the extra volume of gas go when it expands? This is especially troublesome in warm or hot weather when the gas is around 50-55 degrees F. in the ground. The sealed system is filled with gas and then the gas expands because the air temperature is 30 or more degrees warmer. Where does the extra volume go? Maybe into the canister, especially if the car is not driven very far after the fillup and then stays parked for many hours or days. So, filling (not OVER-filling) the tank could cause the canister to become contaminated with gas under certain temperature conditions, in any make of late model vehicle. I don't expect engineers to defy the laws of physics, so I agreed to alter my fillup and driving procedure in the hottest months. This situation is, of course, reversed in the winter, so that a flooded canister in December (even when the temperature outdoors is 60 degrees F., as it was here) can't easily be blamed on a full (not over-full) tank of gas.


Anyway, pretty impressive for a dealership, so far.
Lokamaya is offline  
#12 Old 12-30-2004, 08:05 PM
Official TN Member
 
Join Date: Dec 2004
Location: Pennsylvania
Posts: 239
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 1 Time in 1 Post
iTrader Score: 0 reviews
Where can I get details on the extended 14 year emissions warranty? I was charged for a charcoal cannister on my 98 Camry...a charge I don't think was justified. Can I get this info from Toyota? Thanks
lenjack is offline  
#13 Old 12-30-2004, 08:23 PM
New TN User
 
Join Date: Dec 2002
Location: Indiana
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by lenjack
Where can I get details on the extended 14 year emissions warranty? I was charged for a charcoal cannister on my 98 Camry...a charge I don't think was justified. Can I get this info from Toyota? Thanks
I called the Toyota national customer service number. There are automated questions and buttons to push, I can't remember exactly which ones I chose, probably something that pertained to warranty or recalls. They will look up your VIN to see if your car is covered and then send you a copy of your warranty. It is called Federal Emissions Warranty Enhancement or something close to that.

If your car is covered they will tell you to send a copy of your invoice and proof of ownership and give you the address to send your claim.


800-331-4331
Lokamaya is offline  
#14 Old 12-30-2004, 08:36 PM
Official TN Member
 
Join Date: Dec 2004
Location: Pennsylvania
Posts: 239
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 1 Time in 1 Post
iTrader Score: 0 reviews
Thanks...I'll follow up.
lenjack is offline  
#15 Old 12-30-2004, 08:41 PM
JUST RE ENGINEER IT
 
fredk's Avatar
 
Join Date: Nov 2004
Location: Tooele UT.
Posts: 2,983
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 8 Times in 4 Posts
iTrader Score: 0 reviews
pretty good theory on the gas expansion, but thata an awful lot of air to compress to get the gas to start comming in contact with the top of the tank, if i am not mistaken there is a 1 way check valve in the canister that is opened when the vsv lets engine vacuum get on the other side of it. There has to be a failsafe because cars here in Florida in 110 degree summers would be catching on fire everywhere. I have taken gas caps off cars in the shop during a hot day and there is quite a bit of pressure behind it sometimes. This leads me to this conclusion, most tanks are designed to max fill at 3/4 volume, lets say a 20 gallon will max at 15 gallons, thats 5 gallons of air to compress to 0 volume to get to the top of the tank and start heading down the vent tube, since a diesel engine almost does this at over 1000 psi, there is NO WAY IN HELL a flimsy tin or plastic tank with a cheap plastic fill cap will do this without a leak somewhere in the air chamber above the gas level, and the second reason this cant happen is because the air that got cooled down when the cold gas got put in the tank is now expanding, BUT air expands alot more per degree of increase than a liquid does and that makes it even more difficult for the gas to get to the top of the tank, it will blow the gas cap off long before that happens. There has to be a failsafe somewhere

fredk is offline  
Sponsored Links
Advertisement
 
Reply

  Toyota Nation Forum : Toyota Car and Truck Forums > Toyota Passenger and Sports Car Forums > Camry and Solara Forum > Camry & Solara Lounge

Bookmarks

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome