Factory sub tank - sourcing and fitment discussion

[Casual Cruiser]

An tlc would just move the canister and filter to the wing. The LX has the AHC pump and reservoir in the wing already, so the relo would be to the front of the main fuel tank or the engine bay. The ROW fuel canister is located in front of the main tank.
I liked having the canister above the main fuel tank level, so of to the engine bay it went. Many other cars on the road have the canister in the engine bay. To do it again I’d use the existing tubing to burn off fumes for the connection and it would be a simpler relo.

I have been following this thread with great interest. Now that you have lived with this mod for some time would you enthusiastically reccomend it? What improvements or changes would you make? I understand the different ideas you are considering around the fuel gauge. I have a 2018 TLC that would be receiving this mod. Thank you so much for your time in experimenting and sharing with us.

 

[grinchy]

I have been following this thread with great interest. Now that you have lived with this mod for some time would you enthusiastically reccomend it? What improvements or changes would you make? I understand the different ideas you are considering around the fuel gauge. I have a 2018 TLC that would be receiving this mod. Thank you so much for your time in experimenting and sharing with us.

It’s great. The 12 gallon increase is just right for my 2 and 3 day adventures, and also makes for stress free road tripping when you need to do long days.
Highly recommend and I don’t think the install is particularly difficult, just lots of steps.
I’d do it again for sure. Utility is very high.
Only thing not working perfect is the parallel fuel gauges and that has several alternatives available. I plan to fiddle with it over the winter.

 

[grinchy]

Ah - the only change would be to use the evap hard line from canister to valve cover as the pathway for the evap from rear to engine bay for the canister relo, that removes having to run the evap hose up front and simplifies the install some.

 

[grinchy]

And I’d get the real resistance values off the senders while they were out of the truck, so I could set the resistance network correctly

 

[grinchy]

Will be Using this $10 oem Ford fuel tank switch to switch the gauge reading.
Likely leave it in front (main) all the time, but will have the capability to read the sub if I want.
Plan to put it down by the Tpms reset switch, assuming there is clearance under the steering wheel.
It has a satisfying click and positive detent, too.
Dorrman 901-301

 

[grinchy]

So that fuel switch while totally functional just won’t fit with out a lot of modifications. Basically the entire faceplate would have to be cut away. It’s all one cast piece. So I’m just going to use a bog standard 3 position dpdt switch.

 

[TheIcemanCometh]

What about a switch like this one which says it should fit: Scion OEM Rocker Switch | Scion xA, xB, or tC | Toyota - https://www.oznium.com/switches/gsw-45

 

[grinchy]

I need to switch from one set of inputs for o another (or between inputs if you like)
So a closed circuit for sender 1 or a closed circuit for sender 2.
For convenience I’m going dual pole as that is how it is presented by the senders but a single pole dual throw could also work.

 

[Julian73]

I need to switch from one set of inputs for o another (or between inputs if you like)
So a closed circuit for sender 1 or a closed circuit for sender 2.
For convenience I’m going dual pole as that is how it is presented by the senders but a single pole dual throw could also work.

Try CH4x4. They will issue a custom printed front, if you can't find the extent marks that you want from their list. single pole, double pole, lamination lighting, light while on etc. Oh, and I got a custom switch and was surprised how quickly it shipped.

CH4x4 Custom Laser-Etched Small Push Switches for Toyota

CH4x4 Custom Laser-Etched Small Push Switches for Toyota allows you to operate any 12 volt light or accessory in your Toyota vehicle.

www.ch4x4.com

 

[grinchy]

New basic two way switch perfect.
Not wired up yet but the panel surgery was successful.

Came as a two pack, thinking of putting my locker switch in the middle slot.

 

[grinchy]

Put the switch in line yesterday. Seems to be working for the sub tank (currently empty) as the gauge reads zero and I get the 'low fuel' warning.
THe main tank is around 1/2 full (in reallity). Gauge is showing Full to the gills, I suspect an issue with my (new) extension wiring.

I had a six way switch control sitting around I got for christmas a couple years ago. I went ahead and put that in the vent area. It isn't hooked up yet, but it is reachable while driving and seems to be well out of the way.

 

[grinchy]

Guess I was wrong on the state of the main tank level.
Checked the resistances and got 413 ohm(empty) on the sub tank and 47 ohm(?) in the main tank
Went and bought gas. Put in 13 gallons.
New resistances are 15.2 ohm sub tank and 15.4 ohm main tank. Both switch positions predictably show a full gauge.
I just happened to install the switch at the point that the sub was empty and the main full. Will be watching the gauge closely this first tank but expect no issues.
Also now that I have the actual resistances I may try another resistor network build.
I liked having the single combined readout, just need to improve the accuracy.

 

[grinchy]

The simple dpdt switch works just fine. I did end up having a loose connector, but another turn on the crimper fixed it. No issues after several tanks of fuel. It is a bummer that it has to be physically switched, but it's completely functional.

I do note that the combination meter doesn't query the fuel level very frequently. It seems to take a stop, or a brake, or some other control event to get the gauge to reread. Then it'll do the slow sweep to the new level. It always will check on a restart.

Would recommend this as a simple, easy, inexpensive solution to future adopters of the OEM sub tank.

 

[Dixon Santana]

For those who have added the OEM sub tank. Where have you sourced the filler neck from?
Want to make sure I can source the filler neck before I get everything else.

 

[grinchy]

I think I'm the only victim so far.
I got the filler from Australia, using a site called 'Half Price Parts'. They were great to work with, but I think the stock is hit or miss for specific things. You could call them and see if they'll broker for you with another Australian source . . .

All the filler part numbers are discussed in the first couple pages of the thread <77201-60B00, or 77201-60B10 or 77201-60B90>, I think they're probably all up for the task, mine was galvanized, others are painted, as long as they have two outputs and the vent line interrupted, you'll be ok. <edit - carmaka is showing stock. >

Another, not so bad option is to weld a bung on the US filler. Interrupting the vent line wouldn't be very hard at all either. I think there are side by side pics in the thread <post 161> that should make the mods pretty simple. I've still got my old filler if you want to use it for a core.

 

[Dixon Santana]

I think I'm the only victim so far.
I got the filler from Australia, using a site called 'Half Price Parts'. They were great to work with, but I think the stock is hit or miss for specific things. You could call them and see if they'll broker for you with another Australian source . . .

All the filler part numbers are discussed in the first couple pages of the thread <77201-60B00, or 77201-60B10 or 77201-60B90>, I think they're probably all up for the task, mine was galvanized, others are painted, as long as they have two outputs and the vent line interrupted, you'll be ok. <edit - carmaka is showing stock. >

Another, not so bad option is to weld a bung on the US filler. Interrupting the vent line wouldn't be very hard at all either. I think there are side by side pics in the thread <post 161> that should make the mods pretty simple. I've still got my old filler if you want to use it for a core.

Thanks for the help! Sent in an order through Carmaka.

 

[grinchy]

Thanks for the help! Sent in an order through Carmaka.

It’ll be interesting what you get. They show stock of all 3.

 

[Dixon Santana]

It’ll be interesting what you get. They show stock of all 3.

I ordered the one ending in 60B00. I want to say it's the one with black coating.

 

[grinchy]

I ordered the one ending in 60B00. I want to say it's the one with black coating.

Did the filler ship?

 

[grinchy]

So, it's been about a year. Here's a status update:

Good -
No leaks. Nothing from the relocated canister or new tank to indicate any failure type issues.
I like the simpler 'switch to read' gauge solution, as predicted it stays in 'main' mode almost all the time. Sometimes I will switch it to 'aux tank' to check after a fill up, but usually don't bother.
Fuel Transfer is a non-issue.

ok -
I put the spare back underneath so I could put a bike rack on my swingout. The spare is about level with the diff pumpkin in N mode. A couple inches lower that the standard location.
After the gauge un-combining I am no longer running out of fuel.
When you do run out of fuel, it takes quite a bit of fuel to get the main tank to prime (6 gallons in one event). I think that's because most of the fuel goes into the sub tank, and of course, transfer doesn't happen unless the fuel pump is running. There may be a way to run the fuel pump from the fuse box - or in 'on' mode, I haven't worked on that.

Could improve -
Occasionally the full volume won't go in at a fill-up. Example - I had about 5 gallons left (range of 10 miles). So I should get around 31 gallons at fill. I was able to put in 24 gallons. The main gauge showed about 3/4 (18 gal?). I didn't check the sub gauge, but I bet it was nearly 'full'. I then drove around for 10 min running errands, and went back to the station. At that point the main gauge showed max full (transfered all it could from sub tank) and I was able to put in 8 more gallons no issues. When the pump cut off on the first fill, I knew it wasn't full. But it wouldn't take any more (immediate shutoff). I'm not sure why the flow down the filler to the main tank wouldn't occur in this situation.
This has happened a couple times, but not every fill. Maybe some air burping is required somewhere. It may be that there is some sort of back flow turbulence from the sub to main tank in the filler neck (the sub tank Y is pretty close to the top) that happens when the sub tank is full. Not sure. It's not a huge issue. If I had this happen at that 'last fill' before a long dry section, the solution is to idle in the parking lot for 10 minutes to transfer the fuel into the main, and finish the fill up. Inconvenient, yes, but not super inconvenient.

To-do -
I'd like to swap out the fresh air filter after the evap canister for a higher flow (newer, cleaner, etc) version. Just haven't done it.