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Discussion Starter #21
I completed the switch install and wiring. Still need to terminate the connections at the tank but that will happen after the tank is installed. The interior work is all done though.
Couple of pictures of the installed switch, very happy with this location. And a hand drawn update of the switch schematics.
 

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Discussion Starter #22
Quick question on thread sealant... Yes or no, and which type?
There are a number of brass NPT fittings that will go into steel female fittings on the tank. Seems I remember someone telling me you weren't supposed to use sealants on NPT fittings because they were meant to compress and seal themselves, but a quick google search says that is false. I know teflon tape is a no-no for fuel systems because the bits can clog the filter. But what about the pastes and fluids, anyone have practical experience with which products hold up the best? TIA.
 

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always a good idea to use sealer on threads that are meant to seal, just as a backup/precaution

use any good quality automotive sealer that is fuel resistant and you should be fine
 

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This is awesome!
Can't wait to see the installation pictures. The more the better.:blueblob:
 

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Discussion Starter #25
Went to the lake today, so didn't get much done on the install. I installed the bracket to relocate the main fuel pump control module.
 

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I'm interested in this tank. Please provide good details (before and after photos) on how this tank fits around the exhaust. I have the Allpro tail pipe. I guess I could call the vendor and ask to see if the tank will work with it but there's nothing like seeing how the gas tank will be mounted and what space it is going to take up. Thanks for documenting this and researching the auto fill option.
 

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Discussion Starter #27
Electrical.....3 - More information on the optional on-off circuit.

I've been doing a lot more research on the main tank fuel level signal over the last week. Understanding the characteristics of this signal is important to getting the automatic function on the APEXUS switch to work properly. In a post above I had mentioned that this was a 0-5V signal based on a few readings I took. But later on I took a few more readings and found out I was wrong, which led to more research. So, based on a lot more readings during 2 tanks of gas and 3 fill-ups, the ME section in the repair manual, a bunch of emails with an electrical engineer at APEXUS, and some information that @ZerosFJ was kind enough to provide, I think I have a pretty good handle on how this circuit behaves and what needs to be done to make it work with the switch. I still have 2 open questions, but I'll get to those at the bottom or this post.

The Violet/white wire shown in the picture below is the correct wire for the fuel level circuit. The connector shown is the E13 connector, but you can find this wire at 2 other connectors; EL2 and L5. In my opinion the E13 connector is the easiest one to access though.

The voltage on this wire varies between 0.3V when the tank is full up to ~7V when the tank is empty (I never got all the way to completely empty so I'm estimating based on info in the manual). The low level warning light comes on between 6.3-6.5V. Based on the resistance specs found in the manual this lines up with a constant ~0.017Amp current on this circuit.

However, the APEXUS switch needs a 0-V5 signal (either ascending or descending) so I'll need to reduce the voltage a little to keep the max voltage within spec. This can be done with a simple voltage divider circuit shown below. Only requires 2 resistors and a capacitor that you can buy at any electronics supply house. I'll add this to the APEXUS circuit and test it when I get the tank installed. This SHOULD condition the main tank signal to work properly with the APEXUS switch.

HOWEVER: 2 open questions:
1) Is this signal a pulsed signal? Izalusky mentioned in his thread (post 610) that he had measured this signal with a 10Hz pulse. The repair manual does not indicate that this signal has a waveform even though it lists several other signals with a waveform. Just need to hook up an o-scope to verify. This would be the only reason I would need a capacitor in the voltage divider circuit.
2) ******Will the APEXUS switch work with a descending voltage signal? The APEXUS programming instructions state that you can set it up to work with either an ascending or descending signal. But, after reviewing what I've found with their electrical engineer he admitted that descending voltage fuel senders like the FJ has are not very common and they haven't fully tested this function. So even if I get everything conditioned properly there is still a chance it won't work. Won't know for sure until I can do live testing, and if it doesn't I have some ideas on how to trick it using the ascending setup.

I should have time this weekend to make more progress on the mechanical install. I'll post pictures as I go.
 

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Discussion Starter #28
Prep Work.....1 - Install rear support.

This is item #3 in the LRA instructions.
There is rear support bar that mounts between the frame rails in the rear. This will support the back half of the tank. The bar comes with 4(2 for each side)x 12mm bolts with welded tabs. I'll show the reason for the tabs below.



At the very rear of the frame rail, on the inside of the rail, there are 2 oval holes. These need to be drilled out to 12.5mm (~1/2"). On the left side the trailer wiring harness might be clipped into one of these holes. Just need to give the harness a tug and the clip should pop out of the hole.



Just in front of the 2 oval holes is another, larger rectangular hole. The welded tabs on the bolts are so you can feed the bolts through this hole and maneuver them into place.



The bar is a tight fit between the rails, so you have to get it in place before you insert the bolts. Once it was positioned I used 2 bolts to hold it in place while I maneuvered the other bolts in place from inside the rail. Then tightened it up with the washers and lock-nuts.

 

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Discussion Starter #29 (Edited)
Prep Work.....2 - Cut off brackets (EDIT) and wrap exhaust

This is the last part of item #2 in the LRA instructions.
There are 2 mounting brackets welded to the frame cross member just behind the rear axle. Or the same cross member that the panhard bar is mounted to.
I used a side grinder to cut them off at the weld, and then smoothed the rough spots on the weld. You don't have to grind them flush.
Then three coats of paint from all directions to prevent rust.

EDIT: This would be a good time to wrap the exhaust pipe with heat shield. I didn't think to do this until after the tank was finished and it was a pain. Putting this note here for anyone who may use this thread for instruction later.
 

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Discussion Starter #30
Prep Work.....3 - Tank fittings

This is most of item #4 in the LRA instructions.

Assemble the pump by adding the filter and fitting. The filter goes on the INLET side of the pump, the fitting goes on the exhaust side.


Be careful to notice this label stuck on the tank. It is not in the instructions at all. I dropped the magnet through the rollover valve hole so it sits in the center of the bottom of the tank. Should be a good location to pick up metal shavings.


Then install the rollover valve. It goes in the center hole (~1.5") on top of the tank. Install the grommet first, then push the valve slowly through the grommet, then secure the 1/4" x 1100mm tube to the barb fitting using a small hose clamp. The barb should face the front of the tank when you are done.



Finally install the 2 brass fittings. A 1/2" x 3/8NPT straight fitting goes near the inlet tube. A 5/16" x 1/4NPT elbow goes on the top front. Make sure the barb is pointed toward the front of the tank. Use fuel approved thread sealant to ensure you don't have any leaks.
 

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Discussion Starter #31
Anyone know how sensitive the pressure/vac test is for the evap system?

I have a few issues with the instructions for replacing the filler neck and I'm thinking about replumbing all the oem fill tubing with the appropriately sized rubber tubing. This would mean replacing 3-4ft of hard piping with reinforced rubber fuel hose which would give a little more during a pressure test.

The concerns I have are: 1) The instructions ask that you hack off a few pieces of the oem neck to use for splice sections. I abhor the idea of hacking up original parts when the consequences of screwing it up would leave the truck inoperable. And 2) The instructions do not match the parts on my truck so I'm going to be adding some adapters anyway. I'll post more about that later when I understand more about why the differences exist.
 

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Anyone know how sensitive the pressure/vac test is for the evap system?

I have a few issues with the instructions for replacing the filler neck and I'm thinking about replumbing all the oem fill tubing with the appropriately sized rubber tubing. This would mean replacing 3-4ft of hard piping with reinforced rubber fuel hose which would give a little more during a pressure test.

The concerns I have are: 1) The instructions ask that you hack off a few pieces of the oem neck to use for splice sections. I abhor the idea of hacking up original parts when the consequences of screwing it up would leave the truck inoperable. And 2) The instructions do not match the parts on my truck so I'm going to be adding some adapters anyway. I'll post more about that later when I understand more about why the differences exist.
Gday CR,
Can't comment of the vac test ...codes....
But another option for the filler tube....is to use an OE dual neck...
I got one when doing the Aux instal, let me dig out some pixs....tomorrow....of the OE tank and dual pipe etc...
It would result in a delay, till you get it...etc....
Or check with BeastWagon, see if he has a used single filler pipe ...cut it up...and preserve your's.
Cheers
Baz
:blueblob:
 

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The key point is to pressure test it before installation (block off each end and pressurize through a Schrader valve which you've threaded into one of the plugs you fabbed up for this purpose).

My theory is that the ones that kept throwing codes had a small leak somewhere, because some other folks have added aux tanks without getting codes. In reading through the threads here it is hard to tell who got codes and who didn't, and of those who did if they ever found the root cause or simply kept resetting them over, and over, forever.

In direct answer to your question: the amount of volume you are adding to the system for the Aux tank, if that won't throw codes then you can rest assured that any flex of your filler pipe won't either.


N
 

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Discussion Starter #35
The key point is to pressure test it before installation (block off each end and pressurize through a Schrader valve which you've threaded into one of the plugs you fabbed up for this purpose).

My theory is that the ones that kept throwing codes had a small leak somewhere, because some other folks have added aux tanks without getting codes. In reading through the threads here it is hard to tell who got codes and who didn't, and of those who did if they ever found the root cause or simply kept resetting them over, and over, forever.

In direct answer to your question: the amount of volume you are adding to the system for the Aux tank, if that won't throw codes then you can rest assured that any flex of your filler pipe won't either.


N
Good point about the additional aux tank volume, I guess I was focused on the main tank. I'll have to see if I can find a valve and fitting to do a pressure test, but frankly the only area I'm worried about is the rollover valve fitting on the aux tank. See post #30 in this thread; it is a plastic fitting pushed through a rubber grommet. It's seems to have a pretty good seal now, but I can imagine this would dry-rot over a few years and start to leak. Why is this designed differently when every other fitting is a hard pipe fitting?
 

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Discussion Starter #36
Here's the issue I've run into with the filler neck.

The OEM filler neck has 3 tubes; 25mm fill tube, 16mm vent pipe, 6mm overflow tube. The fill tube and overflow tube are continuous hard pipe almost to the main tank. This is different than the OEM filler neck shown in the pictures, which only has 2 tubes; 35mm fill tube, 8mm vent pipe, and does not extend very far past the first bend. I haven't had time to research yet whether this is a difference in model years, or country specs.

The filler neck supplied by LRA has a 35mm fill tube for the main tank and an 8mm (5/16") fitting for the vent tube. There is no connection for the 6mm overflow tube from the main tank, and no instructions for it. If you look closely, you'll also see that the 8mm (5/16) vent tube fitting is screwed into a reducing bushing before it is screwed into a larger fitting on the fill neck, suggesting this neck was originally designed for a larger fitting/tube.

So to make this work I need to:
1) Adapt the 35mm fill tube on the LRA neck to the 25mm OEM tubing.
2) Get a different fitting and tubing to connect the LRA neck to the 16mm vent pipe from the main tank.
3) Determine what to do with the 6mm overflow tube from the main tank. Should this be capped off, or possibly Tee-ed into the overflow fitting from the aux tank?

I'm in contact with Cruiser Brothers, who are working with LRA to get me an answer. They are promising to make it right. I'll post up what they say when I hear back from them.

If anyone has info on the filler neck differences, I'd be interested to know.
 

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Discussion Starter #37
Gday CR,
Can't comment of the vac test ...codes....
But another option for the filler tube....is to use an OE dual neck...
I got one when doing the Aux instal, let me dig out some pixs....tomorrow....of the OE tank and dual pipe etc...
It would result in a delay, till you get it...etc....
Or check with BeastWagon, see if he has a used single filler pipe ...cut it up...and preserve your's.
Cheers
Baz
:blueblob:
Thanks Baz, I'm definitely interested in how the OE dual pipe is installed.
The parts they want you to cut off your OEM tube is just used to splice the old tubes to the new. I can get some short sections of brass tubing, of the right size, to do this instead of buying a whole filler neck. IMO LRA should have supplied these in the first place instead of having you destroy your OEM part.
 

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Thanks Baz, I'm definitely interested in how the OE dual pipe is installed.
The parts they want you to cut off your OEM tube is just used to splice the old tubes to the new. I can get some short sections of brass tubing, of the right size, to do this instead of buying a whole filler neck. IMO LRA should have supplied these in the first place instead of having you destroy your OEM part.
G'Day CR,
Mate, I am still trying to find the pixs, I took of my tank...must be on my home puter....
Yes I'm surprised LRA didn't include a Y section...its integral to the build...
I had trouble with my tanks breathing, until I figured out the main tank breather doesn't go up the filler pipe... once I changed it to breath back to the aux tank ..and the aux tank goes up the filler.... it works ... I was getting a fuel lock when filling....

I'll keep hunting for the pipe pixs, and aux tank inlet pipe pixs...etc....

I'd be reluctant to start chopping the OE pipe too....
Using a new brass tubing ...sounds better to me...

I bought a new OE dual neck for mine, had to get it from Japan...took about 3 weeks and $300 ....

So I'll find some pixs...or take new ones ....

Cheers
Baz
:blueblob:
 

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G'Day CR,
another thing to put in the pot to ponder...
designed n build to Aussie standards ... the LRA was never meant to deal with snow/salt ..and all the northern winter nasties you get...
The exterior looks good now.... but after a year or two ...I'm worried it will be corroded and rusty..... might be worth doing something about it now...to increase the resistance to northern winters...... not sure what exactly.... por ? or something....
cheers
Baz
:blueblob:
 

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g'Day CR,
I've been trolling thru all my photo's looking for one in particular....but I just cant find it....
found lots of the tank/install ....but the one of the new dual filler pipe... escapes me...

Here are a couple, showing it fitted .. but wont help you much. I also have the exploded parts drawing of the OE tanks, if thats any help...

cheers
Baz
:blueblob:
 

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