YJ Fuel Cell Complete write-up with pics and part numbers - JeepForum.com
 1Likes
Reply
 
LinkBack Thread Tools
post #1 of 31 Old 09-15-2019, 02:50 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
YJ Fuel Cell Complete write-up with pics and part numbers

I recently bought a used YJ with a 14 bolt in the rear. The previous owner basically just moved the gas tank to the back seat area. I wanted to have a less rigged looking set-up. I researched possibilities of adding a genright tank and with the 14 bolt and stretch it was not possible. The only way I see this being possible is doing what some people do is to raise the tank (lose back seat area) or do a frame stretch. The frame stretch is the best approach but most effort and expensive. The YJ came with an aluminum fuel cell already so I thought it would be pretty simple. Since there is not a lot of information out there, I wanted to provide more details. It's been a few months so I hope I don't miss anything.


Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
Sponsored Links
Advertisement
 
post #2 of 31 Old 09-15-2019, 02:59 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
The first step is to choose a fuel cell. There is one from Motobilt specifically for the YJ. MB5000 is $400. https://www.motobilt.com/product/jee..._seat_aluminum I did not use this one so can't comment on that install.
I used RCI 2171A. https://www.rciracing.com/alum1.html This is noted directly as tig-welded street fuel cell. you can get it aluminum color, black, blue or red. I spray painted mine black. It comes with a standard fill neck and -8AN connectors for pickup, fuel return, and a rollover / vent. It already comes with the level gauge installed if you buy it online at a place like https://www.jegs.com/i/RCI/821/2171A...hoCqQQQAvD_BwE I think it's about $250. Dimensions are 30'' L x 7'' W x 17'' H and it tucks in behind the back seat. It holds 17 gallons. I think a 19 gallon fuel cell can fit, but I'm not sure.

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #3 of 31 Old 09-15-2019, 03:05 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
This is where there is not a lot more information. The next question is whether to run the stock mechanical fuel pickup or an external fuel pump, and whether to keep the RCI pickup or add more pickups. People have successfully mounted their stock pump or used a kit to add a TJ pump. The advantage is keeping it stockish and the pickup includes a level sensor and the pump is in the tank itself. I've read all about external pumps not being made to support this application and about folks who have had no issues with the external pumps. I found it way easier to use an external pump and I bought an extra in case the one installed fails.

So, at this point, we have an RCI 271A fuel cell and have decided to use an external pump with additional internal pickups.

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
 
post #4 of 31 Old 09-15-2019, 03:06 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
To get this to adapt to your YJ, you'll need some more items... mainly

An external fuel pump, adapters to adapt to the stock hoses, & a way to secure the tank.

There is already a pipe going to the bottom of the tank that can be used as is, however, I heard stories of people losing fuel pressure when wheeling with low fuel levels and at inclines / declines. To prevent this, I followed another post here and added some walbro fuel pickups in the corners. https://www.pirate4x4.com/forum/jeep...e-request.html

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #5 of 31 Old 09-15-2019, 03:09 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
Let's start with securing the tank because that is easy... I bought a kit, RCI 7514A. It comes with rubber for the straps, but note that I suggest using additional rubber underneath the tank itself. It adds about $50 but is quick and easy. Some people just use eye bolts and straps. You'll want to be sure this thing stays in place if you ever roll and still has a bit of flex (i.e. with the rubber). Plus the rubber helps any corrosion. I have read a lot of stories about these fuel pumps leaking and I think that's due to too much movement https://www.summitracing.com/parts/rci-7514a

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #6 of 31 Old 09-15-2019, 03:12 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
Did you know fuel cells could explode? I did not, but apparently the sudden sloshing or jarring of the fuel inside can change pressure rapidly causing an explosion. To reduce / prevent this, it is suggested to use fuel cell foam, which essentially absorbs the movement of fuel. Apparently this needs to be added to the tank by hand through the gas portion removed. The foam eventually dissolves so it's suggested to replace yearly. For safety I suggest this. If not do at your own risk. I didn't add the fuel cell foam to my fuel cell and I cannot find anywhere online where recreational Jeepers added fuel cell foam. It's very cheap and suggested. https://fuelsafe.com/motorsports/fue...lacement-foam/

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #7 of 31 Old 09-15-2019, 03:19 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
Here's a picture of how I installed the straps. I basically bolted them to the floor. Be careful of where you bolt since there is a bumper back there to consider. Note that you'll also want to consider spare room for closing your tail gate as well as room for running hoses as well as where the seat back will hit or any roll bars. Speaking of this... think that any back seat passengers will essentially be snugged up to the gas tank. In older Jeeps, like the CJ's, the driver actually sat above the gas tank.
Attached Thumbnails
IMG_3770.jpg   IMG_3769.jpg  

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #8 of 31 Old 09-15-2019, 03:26 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
Now let's talk adapting the fittings to the hoses. I did not go with making my own fuel hose compression fittings. If you know how to do this, you can likely make this install easier. Instead, I adapted the -8AN fittings to the factor fuel hoses. I learned a lot about AN fittings. Your fuel cell will look like this and I confirmed at least for my 91 YJ that the fuel supply (fuel pickup) is 3/8" ID hose. The fuel return (is 5/16" hose) and the vent / rollover is 1/4" hose. Note that the TJ's don't have a return fuel since the fuel rail regulates the pressure. In our YJ's, excess fuel is piped back into the tank. This is another reason why it is good to have more pickups so return fuel isn't splashing the RCI pickup pipe. More on the pickups later. Here's an indicative overview diagram. Note the corresponding hose lines. We need to adapt those to the -8AN fittings.
Attached Thumbnails
Overview.jpg  

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #9 of 31 Old 09-15-2019, 03:38 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
I could not find a direct -8AN to the correct hose fitting, so we essentially will reduce the -8AN to a -6AN and then add to our factory hoses. Below are the part's I purchased. Remember our 1/4" vent line, well I couldn't find a -6AN to 1/4" nipple so I converted the 1/4" to 5/16" hose. Now our rollover vent and fuel return will be 5/16". The fuel pickup is still 3/8". You'll basically install the -8AN to 90 degree adapter on all 3 fuel cell connections. On the fuel return and rollover, you'll install the AN8 to AN6 adapter then, the AN6 to 5/16" barb adapter. For the fuel pickup, you'll install the AN8 to AN6 adapter then, the AN6 to 3/8" barb adapter. Then use hose clamps to connect to factory fuel lines. Note I didn't show the step about running the fuel lines through the tub, but be sure to protect them with a grommet so they don't vibrate and get cut. See picture below for the connection closeup.
Attached Thumbnails
AN Adapters.jpg  

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #10 of 31 Old 09-15-2019, 03:50 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
You also need to buy Permatex part 85420, which is fuel safe gasket maker. Regular gasket makers will dissolve over time and could clog your filter or burn in the engine.

Also, please note, blow into the roll over vent / evap hose to make sure you can blow through it. Don't suck as there may be gas fumes. The reason you need to do this is to make sure it is not blocked. If it is blocked, the tank cannot vent and will build pressure and could burst, especially in the heat.
Attached Thumbnails
IMG_3772.jpg   IMG_3773.jpg  

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #11 of 31 Old 09-15-2019, 03:54 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
Now let's connect the fuel gauge. You'll probably be happy here since your stock one doesn't work. Apparently there are 3 wires going back to the stock fuel pump and built in gauge. The red (iirc) is power, the black with brown stripe is for the level sending unit (the one that changes resistance) and the black with yellow stripe is the ground. Wire those two up to the rci fuel cell sending unit. Apparently it's some type of 90 ohm sender which is common and works directly with the stock fuel gauge. Yeah.
Attached Thumbnails
Sending unit.jpg  

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #12 of 31 Old 09-15-2019, 04:06 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
Now let's hook up the fuel pump. Remember that 3rd wire from your factory unit. That's the power for your new fuel pump. Note that the side with the wires goes to the front of the vehicle. You can run a ground to the frame rail like the picture below. I'm not sure if I had to adapt any hoses here, but I don't think I did since I bought the following fuel pump e2000 and used the mounts that came with it and self tapping screws to mount the fuel pump to the rail. You could zip tie it, but the bracket is a much better idea. Note that you need to install a pre-filter. This is required. I bought this one with the correct 3/8" connectors.
Attached Thumbnails
fuel pump.jpg   fuel filter.jpg  

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #13 of 31 Old 09-15-2019, 04:09 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
I also bought a spare fuel pump so please do that as well. Here's a pic of everything installed. The pump turns on when the ignition is in the acc position. It does this to prime the pump since the pump needs to do work and suck fuel. Note the blue permatex gasket maker on the brass nipple
Attached Thumbnails
IMG_3776.jpg   IMG_3775.jpg  

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #14 of 31 Old 09-15-2019, 04:12 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
You can run it just like it is... or if you want to add more pickups in the tank, read on to the fun part.

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
post #15 of 31 Old 09-15-2019, 04:17 PM Thread Starter
gtg413i
Registered User
 
gtg413i's Avatar
2003 WJ 
 
Join Date: Jun 2011
Location: Bay Area
Posts: 1,827
Here's where there is not a lot of information. I found out that the suck-up tube / downpipe is 1/2". Even the owner of RCI didn't know that. We need to convert a tube to a nipple. In order to do that, you need to cut some of the tube then use a 1/2" compression fittings, then run fuel submersible hose to the walbro pickups. My gosh this one was very confusing. If you know how to make fuel compression fittings then you can do that instead. My fittings are all bolt on.

You need a total of quantity 2 of Gates 27093 Fuel Line Hose. i.e. 2 feet x 5/16" ID https://www.amazon.com/Gates-27093-F.../dp/B001R5XSGU They are $18 each 1 foot section and in stock for 2 day delivery.

Brian's Black Betty Build:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
gtg413i is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome