We have a 2003 Sonata and a 2002 Accent, plus I have crawled under a lot of different Hyundai cars in wrecking yards trying to find a good charcoal canister. They have always been located between the gas filler tube and the rear bumper in a plastic box. You have to remove a plastic cover/inner fender to find it.

 

My 2012 Genesis would only allow fueling for 4 to 10 seconds before clicking off. My solution for our California fuel pumps was to turn the filler nozzle 180 degrees upside down . Fills just fine now.

 

The solution on the Genesis is creative, but shows that Hyundai needs to correct the problems. Good news everyone, RockAuto.com has charcoal canisters that are reasonably priced, and instead of using that foam divider, they used felt. Gasoline will not dissolve it. It only cost $70 for the canister for our Accent.

 

First of all thank you everyone on this thread for the help in getting to the bottom of this problem with a 2003 Elantra.

I did check out the canister and as expected it was damaged and there were lots of pellets in the line coming from the fuel tank to the canister. I found the replacement canister (aftermarket) at a decent price locally and changed it out thinking that would be the end of it. Unfortunately, the car would still not take fuel properly so I had to dig a bit deeper.

With the help of this thread I decided to check out the flow from the filler neck to the canister and in the process hoped to figure out if the shut off valve in the tank was acting up. To do this I took the 'from tank' line off the canister and used a Shop-Vac on exhaust at the filler neck to pressurize the tank. It worked well and this process did force quite a few more pellets out of the system that I would not have been able to get to without dropping the tank and removing lines that way.

I read about pressurizing the system on some diesel forums where people use this method to get fuel flowing after running out of fuel or if someone put gasoline in by accident and they needed to 'flush' the systems. I thought it worth a shot and since it was only a shop-vac it did not generate an extreme amount of pressure in the system. Just enough to force the remaining pellets out for me.

I figured I'd share this with the group since this post was so helpful to me along the way.

Thanks again everyone......

 

I like the idea of the shop vac. I was also thinking that there are small vac tools available for cleaning computers, including a small nozzle that might be a good size to blow out the various lines. Once I got our Accent filling at a reasonable rate, I then checked the air filter to the vapor system, and it was plugged. It is a terrible design, there is a small piece of filter paper to the outside air, then 2 others that are progressively larger. Backwards!! I had cut it open with a reciprocating saw, so I removed the filter paper, and put dacron fibre fill in the housing. I used silicon sealant to glue it back together, reinstalled it, and it now fills without any problem. I checked the dacron (it is used in upholstery and quilting) with some gasoline, and it does not dissolve in gas.

 

When I used the shop-vac to blow down the filler neck I used an attachment that I also use to blow out the lines on my pool when winterizing it. It's a cone shaped attachment that tapered well and just about fit perfectly in the filler neck. I also wrapped an old tee shirt around it so that I was not blowing any debris into the tank.

 

Hi, Thanks so much for this post. I have a 2012 Hyundai Genesis with the same problem. I found the Evap Charcoal canister along with the Purge Valve bundled together for sale on Ebay and installed. This fixed it.

 

awesome thread, lots of good technical info. I'm just starting out with this problem, and I'm a HD mechanic, not auto so I don't know anything about EVAP systems lol..... wondering if anybody has an actual picture/diagram with call outs or numbers that shows all these parts of the fuel and EVAP system? I'm following along the trouble shooting, but visually I don't where each of the components are, or which is which under there. I have a 2003 elantra GT..... anybody have a diagram that would pertain to that car?

 

The vapor system traps gasoline vapors in charcoal, rather than venting it as with cars about 50 years ago and more. The system allows air to be pulled through the charcoal to remove the vapors, and take them to the intake manifold. When you shut the engine off, a small blower puts some pressure in the system to check for leaks in the vapor system. The computer measures the current of the blower to do this. If there is no leak, the current is LOW, if the current is HIGH, there is a leak, and the blower is pumping air. Some problems: the charcoal canister has a foam membrane that can dissolve in liquid gasoline. The charcoal granules get pulled into the system clogging it, which can trigger the check engine light. When it is clogged, it is difficult to fill the tank. Another problem is there is an air filter to let air in and out of the system. It can get clogged with dirt, making it difficult to fill the tank (this was the main problem with my Accent). The liquid separator can get clogged with liquid, not allowing the system to vent.


The DM-TL is the electric blower. Air filter was clogged on mine, and the big box holds the charcoal granules.

 

Here is the hose and electrical diagram.


M is the blower. ECM is the Engine Control Module (computer).