Anybody build their own aux tank? (1 Viewer)

[Jstawgn]

LRA does make a 24 gallon tank but it does not really fit KDSS equipped vehicle. Plus It comes with pretty hefty price tags. Don't really need that much capacity and weight but additional 10-20 gallon would be nice.

The OEM subtank is nice but seem tracking down the parts and relocating the evaporative canister is more hassle than I want.

Seen a few on 3rd gen 4Runner using 20 gal 90-97 F150 sub tank. 80 and 100 series using 20 gallon S10 Blazer. All of those does not have Evaporative canister and roll over safety valve.

I am thinking use same apexus PG210 Controller and OEM dual fuel tank filler neck with some OEM tank from other vehicle.

Anybody got any idea what USDM vehicle fuel tank that might fit easily. XJ cherokee plastic tank might fit with some custom shaping to clear the evaporative canister.

 

[CO_Hunter]

I am guessing a racing fuel cell wouldn’t work or someone would have done it by now. Short filler necks are available for them.

 

[Jstawgn]

EVAP system diagram from 05 manual

OEM Plumbing diagram from 05 manual

LRA 200 series Plumbing diagram

 

[Jstawgn]

Mysterious candidates that might fit. Was listed on eBay as Honda Element but it's a GM part. Searching for image of cobalt, cruze, malibu and impala did not show same fuel tank

The exhaust might get really close to the edge of the tank.

Image of Prado with subtank filler neck courtesy of @Toyoland66 which gives me this idea.
I have to rethink this method. The filler neck are different between KDSS equipped and non KDSS equipped. This would run into interference with the KDSS rear cylinder.

Seems the outlet of the filler neck might line up fuel tank really well.

 

[Toyoland66]

Do you have the leak detection pump version of the charcoal canister? If not you may be able to just run a prado canister under hood which is a pretty simple setup.

on my swap the evap stuff has been the biggest headache. I discovered that with the OEM pump setup, where the aux pumps into the main constantly, it will pump fuel into the charcoal canister unless the plumbing to the canister is modified. i need to update my thread with the specifics.

 

[Jstawgn]

Do you have the leak detection pump version of the charcoal canister? If not you may be able to just run a prado canister under hood which is a pretty simple setup.

on my swap the evap stuff has been the biggest headache. I discovered that with the OEM pump setup, where the aux pumps into the main constantly, it will pump fuel into the charcoal canister unless the plumbing to the canister is modified. i need to update my thread with the specifics.

All GX in US use the leak detect version of the EVAP. I need to keep this functioning because I don't have the capability to modify the software. With any check engine light it would also disable ATRAC which is very important to me on the trail.

I am going to use separate pump like LRA and I am hoping to find a port in OEM tank where I can dump it easily or near the filler neck to the OEM tank like the LRA diagram above.

 

[Jstawgn]

Looks like the prado with subtank filler neck would interfere with KDSS cylinder. I already order non KDSS with dual tank filler pipe from UAE. Looks like I would have to sell it.

LRA have to cut the OEM filler neck and insert a tee. I would do the same with this install.

Some other fuel tank that possibly fit. Pending dimensions check.
Have to be:
1. Less than 36" long
2. Less than 22" wide
3. Filler neck toward the front left is preferable.
4. Some clearance toward rear axle pumping to accommodate EVAP canister.

This one might be the easiest to fit

 

[Jstawgn]

Anybody got access to 2015+ Cherokee?
Need measurements of width length and heigh. This seems to be the best candidate for now.

My dual tank filler neck arrived and it would interfere with rear KDSS cylinder. So I would have to sell it. $150 shipped in Continental US if anybody interested. Cost me $210 shipped from UAE.

 

[Jstawgn]

Took a gamble and bought a 2013+ Cherokee 2.4 L FWD with federal emission tank and it fits almost perfect. This same exact tank are used on dodge dart and chrysler 200 from same generation.
Paid $50 and come with the pigtails. The sending unit unfortunately was broken.

Need to get the tanks strap and figure out how to mount it. Also not sure to convert the fuel pump to external or keep internal. Apexus PG210 only have 5 amp max rating and I am worried this would pull more. External are cheap but I still have to buy replacement sending unit or just glue the old one back together.

 

[OffRte66]

Lurking hard over here... Good job!
But I have a question.

Does it matter in which direction the fuel tanks were originally mounted on their respective vehicles..? I'm thinking interior baffles, and wondering about how 10gal of fuel is about 80lbs(?) sloshing around.

 

[Jstawgn]

Lurking hard over here... Good job!
But I have a question.

Does it matter in which direction the fuel tanks were originally mounted on their respective vehicles..? I'm thinking interior baffles, and wondering about how 10gal of fuel is about 80lbs(?) sloshing around.

That is very good question that never cross my mind. There are no baffles looking inside the tank. The baffle are part of the fuel sending unit. This makes me want to keep the sending unit instead of converting to external pump.

On the other hand there are no starvation risk since it would only need to dump fuel to the main tank. It does not need to maintain constant fuel pressure to supply the engine.

Interestingly Dodge Dart sending unit are oriented differently than Cherokee.

The 2 tower design is the one that cause it to break easily.

 

[OffRte66]

Good point.. It's not the main tank, probably doesnt matter as much. Thanks!

If youre putting the transfer pump on a switch, I'm sure whatever pump you choose will last a bit longer regardless of design or brand.

As long as it fits and gives you good readings on the fill state of tank number 2.. Aw crap, is there a way to isolate the float from the pump?

Else for constant readings, youd need constant power on the pump itself and the switch idea goes out the window.

 

[Jstawgn]

Finally commit to the project. Cut spare tire cross member out tonight. Use diablo medium carbide sawzall blade and it make short work out of it. .

The departure angle should not be a problem

EVAP canister does not need to be relocated

Was afraid the EVAP filter would need to be relocated but it clears.

Plenty of clearance between Tank to hitch. Might even able to fit something else.

To do list:
1. Figure out how to mount the tank.
2. Make a pipe for filling from main filler neck and putting the gas back to main tank. Most likely it's going to look similar to how LRA GX tanks is connected.
3. Get a fuel sender to gauge converter. The resistance are different from Mopar sending unit and the apexus PG210. Found on eBay for about $37. I would add a relay to power the in tank fuel tank.
4. Get replacement sending unit.

 

[Jstawgn]

If youre putting the transfer pump on a switch, I'm sure whatever pump you choose will last a bit longer regardless of design or brand.

As long as it fits and gives you good readings on the fill state of tank number 2.. Aw crap, is there a way to isolate the float from the pump?

Else for constant readings, youd need constant power on the pump itself and the switch idea goes out the window.

The PG210 is a gauge and a switch combo with automatic shutoff capability. It's a very slick switch and pretty affordable. The only problem is it need 0-90 ohm fuel sender. Also its only rated for 5 amp. I would add a 10 amp relay and fuel sender converter.

Fuel Gauge to Sender Ohm Range Converter Module For Update Gas Tank or New Gauge | eBay

Fuel Gauges are designed to work with a specific ohm range. This can cause problems for a person who is updating their vehicle with new gauges or a new gas tank and fuel sender. Fuel Gauge Interface Module Ohm Range Converter for Any Fuel Gauges to Match Specific Ohm Range.

www.ebay.com

 

[OffRte66]

Looks like you've got it covered.

That modulator has nice features too. Opens up a range of possibilities when it comes to dampened gauge types and fuel sensors.

Keep up the good work!

 

[Jstawgn]

Been side lined for a while. Just starting to gather parts to start working on this again.

LRA tank came with this adapter to tee to the aux tank and also as the Inlet from the transfer pump.

I can make a one piece later but I think I would d use this as mock up first.

Also found the adapter hose that would connect to the Cherokee tank.
Its actually a Toyota Sienna filler hose. 25mm - 33 mm fuel filler hose FNH204