100 series factory Aux tank

[AndrewP]

Right now I have this much nailed down;

• Factory over the spare aux tank - done
• Dual filler with selector valve - need part number, source from Spressos man in Japan.
• Use internal fuel pump and sending unit for fuel transfer and monitoring aux tank - Verify pump and sending unit are there and functional.

Yet to DO;

• Identify additional "Toyota only" parts required and source/order them
• Create list of ancillary parts required and procure them
• Resolve fuel transfer control automatic vs manual start stop.

Call George Scolaro and get one of his control modules. It's the best $25 you will ever spend. The module is far more sophisticated than you would think. You need a switch too-try and get a factory one so it fits in your dash cut outs. It's just a momentary switch if you want to source your own.

Borrow Ali's Riv Nut tool. It is the Mac daddy for mounting the rear of the straps.

The hardest part was figuring out what wire does what at the connector to the fuel pump. The wire diagrams floating around on the web are often wrong and clearly it varied from year to year.

Once you do that, it's just a bunch of wires to and from the pump and sensors. If I can figure it out, there is a 100% chance you will be able to figure it out.

 

[Hedge]

How do I find George?

http://george4wd.taskled.com/auxtank.html

 

[rusty_tlc]

Call George Scolaro and get one of his control modules. It's the best $25 you will ever spend. The module is far more sophisticated than you would think. You need a switch too-try and get a factory one so it fits in your dash cut outs. It's just a momentary switch if you want to source your own.

Borrow Ali's Riv Nut tool. It is the Mac daddy for mounting the rear of the straps.

The hardest part was figuring out what wire does what at the connector to the fuel pump. The wire diagrams floating around on the web are often wrong and clearly it varied from year to year.

Once you do that, it's just a bunch of wires to and from the pump and sensors. If I can figure it out, there is a 100% chance you will be able to figure it out.

After reading the info on Georges site I may not need the riv nut tool. The tank came with factory brackets. I think I'll see if Spresso wants to come over this weekend and do a dry fit.

I'll call George and see if he has a problem with me cloning his schematic. I make stuff like this everyday, so unless it cost out at the same or more than his cost for parts I'll probably build the PCB myself. My gut feel is the relay and connector alone will cost close enough to his price that I'll buy from him.

On the other hand if I need to replace the sender with one from an 80 to use his PCB (see Georges comments below) I may as well design a circuit on my own that works with the existing sensor to sense the fuel level and shut the pump off.

http://george4wd.taskled.com/auxtank.html

Thanks for the link.

Reading this I'm thinking the 100 is a lot closer to the 105 than an 80 and I should have less issues. If it really is a 105 tank that would be sweet, 4 extra gallons. That would certainly obviate the need to ever buy gas on the way to Las Vegas again.:wings:

Here is a summary of the details that I am aware of at present:

* The 105 subtank appears to be slightly larger.
The 105 is advertised to be 65 liters (approx. 17.2 U.S. gallons) as compared to the 50 L (13.2 gal) for the 80 series tank. This may not be correct though, since all Australian references to the 105 series state the subtank to be 50L in capacity.
* The 105 tank support straps are too long.
Designed for mounting on the 105, the support straps are approx. 1-2 inches too long for the 80. The original 80 straps are contoured for the 80 tank, and will not fit the contours of the 105 tank, so the 105 straps appear to be the only solution but require some creative modifications to mount the tank securely.
* The 105 dual filler has different port angles.
Initial trial fitment suggests the mounting the 105 filler neck in the 80 will not be an issue. The ports have a slightly different departure angle, however, and will require at least one preformed hose, or perhaps a preformed filler tube to properly plumb the filler neck to the subtank. This may also be true for the return port.
* The 105 tank uses a different fuel pumping scheme.
The 105 subtank has an integral fuel transfer pump. The advantage is you don't have to mount and plumb a transfer pump externally as you do with the 80 subtank.
* The 105 gauge sender does not have a level switch.
The 105 subtank was designed to pump fuel directly forward to the fueling system, not to transfer the fuel to the primary tank as in the 80. Because of this, the 105 sender does not have the level switch that is required in an 80 to send an "fuel empty" signal to shut off the transfer pump. (Presumably the 105 ECU senses the sender resistance to cutoff the transfer.) The apparent solution is to replace the 105 sender with an 80 sender that does have a level switch. An initial evaluation of this possibility suggests the senders are interchangable, but this needs to be confirmed.

 

[AndrewP]

After reading the info on Georges site I may not need the riv nut tool. The tank came with factory brackets. I think I'll see if Spresso wants to come over this weekend and do a dry fit.

Pretty sure the rear ribs where the straps mount is not drilled so you will need to drill holes and install riv-nuts to attach the strap brackets. I saw these pull out of one truck in DV, and the fix was to make a bracket with a captured nut and weld the bracket to the rib and then install the strap to the bracket. Very secure!

I'm thinking you are very lucky to have found that tank. A filler will be expensive, but not impossible to find.

No doubt that circuit will be easy for you, but with the design and known functionality already built in, it seems hard to beat. It's small, too and fits in a small plastic "project box" from Radio Shack. Even in the box, with connectors, mine fits behind the radio inside the dash.

 

[rusty_tlc]

Pretty sure the rear ribs where the straps mount is not drilled so you will need to drill holes and install riv-nuts to attach the strap brackets. I saw these pull out of one truck in DV, and the fix was to make a bracket with a captured nut and weld the bracket to the rib and then install the strap to the bracket. Very secure!

I'm thinking you are very lucky to have found that tank. A filler will be expensive, but not impossible to find.

No doubt that circuit will be easy for you, but with the design and known functionality already built in, it seems hard to beat. It's small, too and fits in a small plastic "project box" from Radio Shack. Even in the box, with connectors, mine fits behind the radio inside the dash.

Probably the best thing at this point is to pull it out of storage and trial fit it.

I hear what you are saying about the circuit. George has the schematic on his web site, I'm thinking I'll need some more components to make it work with the 100 sending unit anyway so I may as well "borrow" Georges design (only with permission of course) and add the stuff I need on. I looked at his layout and there is plenty of room to add the extra stuff and keep it the same size.

 

[spressomon]

I think he has the A type, don't ask me why.:elkgrin:

Sorry I've been MIA the past couple days ;-)

The answer is here: http://expeditionportal.com/forum/showpost.php?p=552339&postcount=26














Type A for you readers :coffeedrink:.

Here's a photo of the actual filler...it has a spring loaded "gate" at the top.

 

[24HOURSOFNEVADA]

[*]Dual filler with selector valve - need part number, source from Spressos man in Japan.

[/LIST]

I believe this is the part from Dave S. (Japan4x4) that your looking for.


77201-60540 Pipe sub assembly fuel tank inlet.

However, there are brackets and other assorted accessories...

 

[alia176]

Time to give Dan some crap!!

Probably the best thing at this point is to pull it out of storage and trial fit it.

I hear what you are saying about the circuit. George has the schematic on his web site, I'm thinking I'll need some more components to make it work with the 100 sending unit anyway so I may as well "borrow" Georges design (only with permission of course) and add the stuff I need on. I looked at his layout and there is plenty of room to add the extra stuff and keep it the same size.

Borrow "what" from his schematic? Just buy the darn thing and quit your whining :sombrero: Based on the rate of completion for your projects, do yourself a huge favor and just get the ECU, buy the transfer switch from Toyota and wire it up. I am just messin with ya :coffeedrink:

George ECU only cares about a GND signal when the tank goes empty (for pump off). This is strictly a digital signal. So, it doesn't matter if it's a tank from an 80 or a 100 series. Pretty sweet I have to say. I'm sure you've figured this out by now but just in case...

If you want to see the actual fuel level in the aux tank, you can finally put your electronic circuit building prowess and figure out how to use the existing fuel level gauge to see both tanks by flipping a switch. Easy enough to do with a DPDT switch but you'll have much cooler geekness way of doing this I'm sure

Truth be told, i ran the wires to have this functionality back in 2004 but have yet to ask myself, "hmm, I wonder how much fuel is in the aux tank"! So, I haven't followed through with this aspect of the project. If it was a 25 gallon aux tank, that'd be different.

When the time comes, I transfer all of the fuel (whopping 13 gallons!) to the main tank and then forget about it. If I get really bored one day and have absolutely NOTHING else to do, I may trace the dash fuel gauge wire by the kick panel and interrupt it with some wiring from the aux sending unit and a DPDT switch.

 

[rusty_tlc]

This picture if from bajaoverland's site. But I don't know if the labeling is correct. Rosco, by flapper valve, I mean there is a valve inside that diverts fuel to one side or the other.

I believe this is the part from Dave S. (Japan4x4) that your looking for.


77201-60540 Pipe sub assembly fuel tank inlet.

However, there are brackets and other assorted accessories...

Is that for the 100 or the 80. As you can see there are differences.

 

[rusty_tlc]

Borrow "what" from his schematic? Just buy the darn thing and quit your whining :sombrero: Based on the rate of completion for your projects, do yourself a huge favor and just get the ECU, buy the transfer switch from Toyota and wire it up. I am just messin with ya :coffeedrink:

George ECU only cares about a GND signal when the tank goes empty (for pump off). This is strictly a digital signal. So, it doesn't matter if it's a tank from an 80 or a 100 series. Pretty sweet I have to say. I'm sure you've figured this out by now but just in case...

If you want to see the actual fuel level in the aux tank, you can finally put your electronic circuit building prowess and figure out how to use the existing fuel level gauge to see both tanks by flipping a switch. Easy enough to do with a DPDT switch but you'll have much cooler geekness way of doing this I'm sure

Truth be told, i ran the wires to have this functionality back in 2004 but have yet to ask myself, "hmm, I wonder how much fuel is in the aux tank"! So, I haven't followed through with this aspect of the project. When the time comes, I transfer all of the fuel (whopping 13 gallons!) to the main tank and then forget about it. If I get really bored one day and have absolutely NOTHING else to do, I may trace the dash fuel gage wire by the kick panel and interrupt it with some wiring from the aux sending unit and a DPDT switch.

From reading on Georges site the 80 series has definite "empty" signal. I have the 100 tank but no 80 tank for reference. The 100 tank has three wires from the sending unit, which makes me think it may have a definite digital "MT" signal. If that is the case I'll just buy the part from George. I'll noodle that out with Spresso tomorrow.

BTW I priced it out at $6.00 in parts and 2 hours of labor, since I'd do it on company time it probably wouldn't take long to do:sombrero:.

I was reflecting on a gauge last night and I agree, I can see no useful reason to have one. When the main tank gets down to 1/4 I'll just hit the transfer switch and forget about it.

 

[rusty_tlc]

I dropped the spare and the winch assembly this afternoon.
It looks like the captive nuts are already there for the tank straps.
We will try it out tomorrow if I can find some M10X1 thread bolts. (I scrounged around in my misc nut and bolt tin and found a stud from my FJ40 transmission that fit the captive nuts so I know what size I need.)

 

[24HOURSOFNEVADA]

Is that for the 100 or the 80. As you can see there are differences.

It's for the hundy (The same style as Spresso has) and yes, I know there are differences having done the 80 last year.

 

[24HOURSOFNEVADA]

I was reflecting on a gauge last night and I agree, I can see no useful reason to have one. When the main tank gets down to 1/4 I'll just hit the transfer switch and forget about it.

I can tell you from having the OEM aux Gauge in the 80, it's very nice to know how much fuel you have in there. My father has the aux tank for his FJ Cruiser and it sucks not knowing the fuel level in the second tank.

 

[rusty_tlc]

It's for the hundy (The same style as Spresso has) and yes, I know there are differences having done the 80 last year.

Sorry I didn't mean to imply anything. What I'm really looking for is the PN for the neck with the flapper. That's my first choice, if I can't find one in a reasonable amount of time Ill go with the "Y" neck type.

I can tell you from having the OEM aux Gauge in the 80, it's very nice to know how much fuel you have in there. My father has the aux tank for his FJ Cruiser and it sucks not knowing the fuel level in the second tank.

Good G2, I'll make sure I pigtail the wires out so I can add one if I find the need. Right now the plan is to run the main until it is nearly empty then just transfer all the sub tank fuel into it. So "theoretically" the sub will only have two levels, full and empty.

The gauge on my FJ40 aux tank never worked right. It was a switched system, not a transfer system. My tactic with it was to run off the aux tank until it was empty then switch to the main. Even off road I knew I had about 200+ mile range on that tank alone, closer to 300 on the highway. So I always had plenty of time to plan a re-fuel.

 

[rusty_tlc]

Today Spresso and I pulled the rest of the spare tire mounting stuff off and did a trial fit of the tank. It's sweet. There will be no riv nuts needed.:victory:

We couldn't quite get the spare tire lift mechanism to fit back in but I think with the correct hard ware it will all come together. The only bolts I could find were cap bolts 20mm long. I think I need something like 15mm for a tight fit. I'll try to get the correct ones from Toyota next week.

Spresso and I looked at the parts diagram and it looks like I would need to source a butt load of parts to do a true factory install so that is definitely off the table.

I didn't get around to powering up the internal fuel pump or ohm-ing out the sending unit. The sun was breaking through off and on. I couldn't see spending the afternoon inside after the weeks of gloom we have had.

This is probably why it takes me so long to finish stuff.:sombrero: