Where does toyota put the charcoal canister on these with the second tank? Why can't it go where they put it?
Builds FerrisBueller's 2018 LC Build - "Moby" (3 Viewers)
- Thread starter FerrisBueller
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- #82
Because the foreign models either don't use a charcoal canister, or use a much smaller one. The smaller one fits in front of the main fuel tank inside the frame rail, which is much too small of an area for the U.S. version. Foreign markets have different emissions requirements. I have to assume that the electronics in the smaller foreign canister likely would not make the U.S. spec computers happy, and would be an expensive part to experiment with.
Well that sucks! So much for a total plug n play solution then.
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- #84
Yeah, no kidding. But in the end I still prefer this solution over LRA for the convenience of a single fill port and automatic fuel transfer to the main tank.
Personally, there's still too many fuel vapor issues with either setup at the moment for myself to install either one. I watched a buddy struggle with boiling fuel and trouble codes with his 100 Series and I am just not ready to accept that for the sake of a few more gallons of fuel. I'd really like to have a longer range but I can live with a 300-ish mile range for now. Hopefully LRA gets their kinks worked out or you find a better solution for this factory adaptation.
I agree, I'd always pick an OEM/factory solution over aftermarket.
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- #87
Tomorrow afternoon I will have everything I need to relocate the canister to the engine bay. Should be pretty straightforward, I can't imagine it taking more than a couple hours. Probably won't be able to work on it until Saturday, though.
@grinchy I am going to update the main vent line routing to go through the subtank connectors before the canister, like yours. It's not going to be easy to access those two subtank ports with the subtank in place, but I think it's possible. I think in the end that approach will make it easier to use the purge hardline for the vapor vent like you suggested (which will make this whole relocation much straightforward and less time consuming).
@grinchy I am going to update the main vent line routing to go through the subtank connectors before the canister, like yours. It's not going to be easy to access those two subtank ports with the subtank in place, but I think it's possible. I think in the end that approach will make it easier to use the purge hardline for the vapor vent like you suggested (which will make this whole relocation much straightforward and less time consuming).
I don't recall it taking more than a couple hours to bang a couple brackets together and relo the PS reservoir and headlight resistor.
I wouldn't put it on top of the fuse box - just too time consuming to get to the fuses if needed.
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- #89
Yes, I'm planning to put it by the PS reservoir
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- #90
The needle finally started to dip below 'F' after 150 miles 
It’s a good feeling! I just put 17 gallons in on a 3/4 full main tank.
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- #92
I didn't have a lot of free time, but I did spend a little time each day and eventually get the canister moved up front. It's in a state that can be considered permanent, but now that I have a working bracket design, I'm going to design a more professional version after my trip that will be laser cut and bent (and can be ordered 1-off as needed for anyone doing the same thing). Routing the wiring up front actually wasn't too bad, and I was able to avoid getting it too close to the exhaust pretty much the whole way. I ended up not needing to relocate the power steering reservoir. These later models do not have the DRL resistor, either (at least not in that location). These later models' canister also has no threaded holes anywhere, unfortunately, so at first it wasn't obvious how I was going to secure it. In the end I strapped it down like a battery, which honestly ended up being a pretty great solution. It may not look like much, but it's solid.
I did modify the brackets that hold up the spare tire brace, so that they would work correctly with the E&E (@turbo8) rear bumper mounting bolt. Test fit & works perfectly. Painted the cut brackets for corrosion prevention, then will install everything related to the spare tire tomorrow or Saturday. The frame holes for dropping the brackets already exist, but are not threaded. The rearmost two (per side) are the correct size for the m8 rivnut, but the frontmost is smaller and has to be drilled out slightly (7/16" bit).
(Don't worry, I will paint the brackets before permanent installation.)
I did modify the brackets that hold up the spare tire brace, so that they would work correctly with the E&E (@turbo8) rear bumper mounting bolt. Test fit & works perfectly. Painted the cut brackets for corrosion prevention, then will install everything related to the spare tire tomorrow or Saturday. The frame holes for dropping the brackets already exist, but are not threaded. The rearmost two (per side) are the correct size for the m8 rivnut, but the frontmost is smaller and has to be drilled out slightly (7/16" bit).
(Don't worry, I will paint the brackets before permanent installation.)
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- #93
While the canister is sitting on top of those bracket mounting bolts right now, I am going to add two layers of neoprene closed-cell foam padding sandwiched around a flat strip of aluminum stock to ensure that there are no points that will wear through the canister housing. Just waiting for Amazon to deliver the padding.
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- #94
Finally got my spare tire back on. The subtank project is officially complete 
Looking forward to your write up on it!
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- #96
The last two times I've filled up, I couldn't get the pump to fill the main tank all the way full. The subtank was able to fill all the way and the main tank would get up to 3/4 full before clicking off. Not sure why it worked perfectly the first time I filled up, but now twice in a row leaves the main tank at 3/4. I'm guessing somehow the subtank filled too fast and blocked the fill vent line from the main tank?
It's still more range than I had before, and I'll see if there's any variation during my long trip. If it's consistently like this, then I'll have to troubleshoot after the trip.
It's still more range than I had before, and I'll see if there's any variation during my long trip. If it's consistently like this, then I'll have to troubleshoot after the trip.
I get this if the main tank gauge is less than 1/2 (roughly 14 gallons in the main). It seems that the main and sub fill at the same rate, but then when the sub is full the fill line backs up and the pump shuts off from backpressure. This is my theory anyhow.
If I really really need the additional capacity (usually around 5-7g, but could be up to 12g at most) then idling in the station will transfer over from the sub to the main, and then you can run by the pumps again. I think the transfer is around a gallon a minute. I've done the idling one time, and by the time I'd gone to the bathroom and purchased a cup of coffee, the sub was empty, the main was above 1/2, and I was able to top them both off and have maximum off road range.
I put up a couple posts on this at the end of the other thread. It's a mild annoyance, but I find it pretty easy to mitigate (buy gas around 1/2 a tank left if I want a full fill), and the workaround isn't the worst thing ever, idling or driving a couple more exits down to another gas station.
If I really really need the additional capacity (usually around 5-7g, but could be up to 12g at most) then idling in the station will transfer over from the sub to the main, and then you can run by the pumps again. I think the transfer is around a gallon a minute. I've done the idling one time, and by the time I'd gone to the bathroom and purchased a cup of coffee, the sub was empty, the main was above 1/2, and I was able to top them both off and have maximum off road range.
I put up a couple posts on this at the end of the other thread. It's a mild annoyance, but I find it pretty easy to mitigate (buy gas around 1/2 a tank left if I want a full fill), and the workaround isn't the worst thing ever, idling or driving a couple more exits down to another gas station.
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- #98
That's pretty interesting and good to know. And like you said, that's easily workable. For long trips with the extra range, we will likely stop for gas only when we need restroom breaks anyway, so can let it idle while the kiddos are on the restroom and fill the rest of the way up before we take off.
This makes me wonder if the the problem would go away if the main vent was tee'd into the subtank vent so they both have direct access to the filler neck vent. I don't think I'll try that, though. Maybe if it becomes a big enough of an annoyance.
Another thought: since the filler bung for the subtank essentially sticks out sideways, that should cause much more of the fuel to go the straight path to the main tank, but only if the fuel is filling fast enough. With a slower fill rate, I would presume that more of the fuel will drain into the subtank first. I wonder if US fuel stations are regulated to fill slower than foreign stations.
It is curious, though, that I got a complete fill of both tanks right after installing the subtank (and the main tank was at E for that). Just got lucky I guess. I'm trying to think of anything else that would have been different that time compared to now, but the only difference is the charcoal canister relocation, which should have no impact on filling.
This makes me wonder if the the problem would go away if the main vent was tee'd into the subtank vent so they both have direct access to the filler neck vent. I don't think I'll try that, though. Maybe if it becomes a big enough of an annoyance.
Another thought: since the filler bung for the subtank essentially sticks out sideways, that should cause much more of the fuel to go the straight path to the main tank, but only if the fuel is filling fast enough. With a slower fill rate, I would presume that more of the fuel will drain into the subtank first. I wonder if US fuel stations are regulated to fill slower than foreign stations.
It is curious, though, that I got a complete fill of both tanks right after installing the subtank (and the main tank was at E for that). Just got lucky I guess. I'm trying to think of anything else that would have been different that time compared to now, but the only difference is the charcoal canister relocation, which should have no impact on filling.
It certainly could be venting backpressure or some other harder to understand or not obvious cause. It's really hard to say what the root cause is. There aren't any complaints in anything I'vre read or seen for the out of US OEM installs, so maybe it's to do with the different canister/vent design or location.
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- #100
When I did the canister relocation (which was after my first fill-up that didn't have a problem), I did change it to daisy chain the subtank into the vapor line between the main tank and canister. Before that, I just had the main tank vapor line go directly to the canister, and capped off those ports on the subtank.
