Factory sub tank - sourcing and fitment discussion

[grinchy]

Thanks to @CharlieS here is a photo of the top of the US model fuel pump. Note the existing, third input for the sub-tank. I think it very likely that the only parts required to fit up the subtank at the pump are the sub tank hose and clip. May not even have to drop the tank at all if we can fish the hose up from the side.

Fuel Sending Unit

2009 lc200 215k miles. I have a faulty fuel sending unit. Fuel gauge and low fuel light not functioning correctly. I recently ordered a complete fuel pump assembly, might as well replace it all while in there. I have not found much info online and the best that I can see, I will have to lower...

forum.ih8mud.com

 

[grinchy]

Ok. I've squeezed all the unnecessary diesel parts out that snuck in based on the Russia install into that TLC. This list was xrefed only on a Petrol 5.7l, so it's the best fit for a US petrol TLC or LX570.

If you have a diesel just follow the parts as specified in the above linked Russia project, it's quite complete.

Posted here, also cross posted in the earlier post where the other versions are.

$600 exclusive of shipping . . .

 

[ty240]

Not sure if this applies to your parts, but Toyota is offering Free Ground Shipping on $75+ orders of Genuine Toyota Parts and Accessories (maximum $200 value, exp 1/31) when you follow the instructions below:

1. Shop for parts
2. Add items to cart
3. Proceed to checkout
4. At checkout, apply coupon code FREESHIP for free shipping on $75+ orders w/ $200 maximum benefit
5. Complete your order
6. Terms and conditions

 

[grinchy]

Well, this journey is started. I ordered a filler 77201-60B10. I wasn't able to find stock in the 77201-60B90. Going to take a look at the filler before I order the sub-tank. Still mulling options for using an alternative tank.

 

[rcork]

Grinchy,
Thanks for doing all of this and sharing what you have figured out. I'm not 100% up to speed on this filler neck, but does it just have an extra attachment point midway down the large tube to allow fuel to go to either the sub tank or the main tank?
I'm asking because if that is the only difference it would be easy to just add the extra tube to an existing filler neck. Again this assumes that is the only difference.
Robert

 

[grinchy]

Grinchy,
Thanks for doing all of this and sharing what you have figured out. I'm not 100% up to speed on this filler neck, but does it just have an extra attachment point midway down the large tube to allow fuel to go to either the sub tank or the main tank?
I'm asking because if that is the only difference it would be easy to just add the extra tube to an existing filler neck. Again this assumes that is the only difference.
Robert

You could absolutely buy a new standard neck and weld on some bungs, or do some cutting on your current neck to adapt.

I'm usually DIY, but not much of a welder, and if this fails (which it could at this stage), it's easily reversible to just put the old neck back in. That flexibility was worth $175 to me. Not having to ship it 1/2 way around the world is even more approachable, at $80, where I would argue it isn't worth the time to cut up the stock filler.

Earlier in the thread there are pictures of the 'sub tank filler', the main difference is the vent is interrupted as it chain vents both tanks, and the bung for the sub tank to tee out exists.

The other thing the stock neck allows is using entirely standard factory hoses and parts, and I think giving a much more approachable solution for those that aren't experts in emissions management. Since our rigs turn off 4low with emissions errors, it's important to manage that risk as much as possible.

 

[rcork]

Grinchy,
That makes perfect sense. Thanks for the explanation. Now, when this is a proven success and we are all doing it, someone with spare time and tube welding skills could set up a parts exchange supply. Order a modified fill tube, send in your old one for the next guy. Nevermind, I already see the problem with that idea. Never getting the cores back to be modified....
Still excited to see this work for you so I can copy it!!

 

[unclemat]

Following with interest. So question - why not Long Ranger Aux tank? Cost? Prefer OEM reliability?

 

[grinchy]

Following with interest. So question - why not Long Ranger Aux tank? Cost? Prefer OEM reliability?

Cost primarily, OE fitment less so. Simplicity is another. Though I don't think this is really a straight comparison, as the available capacity options with an aftermarket tank are much larger.

The most difficult part for me is coming to terms with the exorbitant shipping costs for the filler and tank. The other, smaller parts are quite reasonable to obtain from international sources.

Filler $100 + $75 shipping
Tank $180 + $240 shipping
Rest of BOM $400 + $100 shipping

 

[unclemat]

The shipping cost is actually not all that bad considering the size of the items. Probably could save on a batch order, but someone needs to be guinea pig first, I suppose. So, yeah, thanks for doing it!

One thing that I read about LRA tanks that bothers me is the issues with filling them with the dual fuel port. OEM simplicity would be awesome - though one likely issue probably will be the fuel gauge. I'd be really surprised if it just worked on the US car.

While I was planning on 24gal LRA, I think I could be okay with ~12gal OEM instead...

 

[grinchy]

one likely issue probably will be the fuel gauge. I

Yes sir. I've been thinking about that too, primarily as the sender and wire are $85 of the BOM.

Here are the wiring excerpts from a 2009 LX570, and the Global LX570.

Let's figure out what else we need to make it work electrically beyond, Wire, Floor, No. 3, which is the sender connector between the sender and the main wiring harness.

It looks to me like we need to get a gander at EK1, and MK1 is the insertion point (if it exists, which I highly doubt), so more really about jumper pinning on EK1.

decoder ring for the Global wiring:
∗ 1 : Except Europe
∗ 2 : Before Jul. 2009 Production
∗ 4 : w/ Telematics System Multi–Display
∗ 5 : Before Jan. 2012 Production
∗ 6 : From Jan. 2012 Production until Jan. 2012 Production
∗ 7 : From Jul. 2009 Production
∗ 8 : Before Jan. 2013 Production
∗ 9 : From Jan. 2013 Production

 

[grinchy]

So much for waiting around and evaluating options after getting the filler. Ordered the balance of stuff. Just a few items left to source in the US, $25 of clips and one standoff. Looking for a valid free shipping code, or I guess I could break quarantine and go to the local Toyota dealer . . .
<edit ordered last few bits from local dealer, which drastically reduced S&H>

 

[grinchy]

Wiring. Ek1 is the existing plug under the car. mk1 and nk1 are the plugs at the senders.
so the new wire, floor no. 3 should somehow daisy chain or plug into ek1 from mk1
the real q is if the wires on pins 13 and 12 out of ek1 exist, and the other real q is if the ecu is watching for a signal on these pins When it’s gets to that connector.
ek1 7,6,5,4 are the sender outs and the ecu side is 15,14,13,12

<edit> Okay, both diagrams above are showing pins 15, 14, 13, 12 into E77 Combination Meter. Now this device does show an EEPROM, so not out of the woods yet, but it has the same name in both diagrams. Worst case is programming doesn't exist on US EEPROM. Next worse is that wires aren't in the bundle for 13 and 12 and have to be added manually, next worst is EK1 is different on US models, and best case is it's plug and play and nothing but the new sender wire is required>

 

[fvunen]

The shipping cost is actually not all that bad considering the size of the items. Probably could save on a batch order, but someone needs to be guinea pig first, I suppose. So, yeah, thanks for doing it!

One thing that I read about LRA tanks that bothers me is the issues with filling them with the dual fuel port. OEM simplicity would be awesome - though one likely issue probably will be the fuel gauge. I'd be really surprised if it just worked on the US car.

While I was planning on 24gal LRA, I think I could be okay with ~12gal OEM instead...

Plus of course the OEM subtank still allows carrying the spare under the car, albeit positioned slightly different. Going for larger sub tanks will require relocating the spare wheel elsewhere.

 

[grinchy]

that's true, the sub tank goes above the spare tire crossmember. I think the small LRA tank allows remounting the spare as well.

It was because I have already moved the spare that I was considering a larger tank. After more consideration, the additional 80-150 miles of range in the factory subtank was enough for the kind of activities I've been doing. And if I'm on some epic trip with very long refill intervals, I guess the 4gal Rotopax will get back in the rotation.

 

[CharlieS]

In case it comes up in a future search: You are correct and I can confirm that the LRA 12.5 gal allows for the spare to remain under the vehicle. It is really the only reason I had for selecting the smallest LRA tank option. I use the rear hatch all the time (pre-pandemic, opening at least 10-12 times a week), and as much as I'd love the rugged aesthetic of a rear mounted spare and the extra space for gear, a rear swing out or two is impractical for my day to day use.

 

[grinchy]

(Edit yes there are changes necessary to the fuel pump assembly)
So, double checking to see if I'm going to be short a 'jet pump'

Here are all the parts numbers for the mounting plate, which is what the pump and sender and valve connect to from below and what the hoses and return line connect to above. A is the US LX570. B is the LX570 with a sub tank

In all instances, they pair across model years. CONCLUSION: This part is the same between those with a sub tank / jet pump and those without.

I did this for all the parts in the fuel pump sub assembly - and got the same conclusion.

The overview pages are similar (evap and emissions differences). The sub tank models get a special three page section on the sub tank.

 

[TeCKis300]

The jet pump is a beautiful thing. A passive device utilizing bernoulli's principle of accelerating fluid flow to create a lower pressure zone, which sucks fuel over from the subtank.

If there's a picture of the fuel tank pump assembly, I may be able to tell you if it's there. It may very well be a common part of the plastic housing.

 

[unclemat]

So you're saying we have the jet pump, it's just not utilized, since the inlet on the main tank where the subtank connects is capped?

I suppose it means it is applying vacuum to the capped port?

 

[grinchy]

Hmm. Good and bad news. I've been trying to puzzle out what 'rear no 2. seat without' means in the parts diagram. After looking at it again, it means 'sub tank'. So . . . easy to figure out which parts are sub-tank only, and also easy to see there are some more fuel parts to add to the BOM.
TL-DR - yes, the 'jet pump' is not in the US LX570, and yes, you'll be dropping your tank or pulling the pump thru the access hatch to update.