Secondary fuel tank question / advice (1 Viewer)

Joined
Jul 30, 2019
Messages
200
Location
Orange County
So my BJ40 came with a secondary fuel tank in the back as extra parts. It has a fuel pump installed and wired. I assume the fuel lines are currently set up to bypass the secondary fuel tank as it is not installed.

I’m trying to figure out any info on how this fuel pump works and how to plumb the fuel tank back in.

I did my best to label the picture to show how the fuel lines are currently routed.

Some questions I have are:
1. Is the secondary fuel tank set up to refill the primary tank when the fuel pump is turned on? Or is set up to bypass the main tank and act as a true secondary fuel tank? Or is it able to do both?

There is only one fuel gauge in the cab.

2. Any idea how the secondary fuel tank hoses are supposed to be routed to the fuel pump?

In the pictures there are 2 hoses coming from the fuel pump. The top hose has a smaller diameter and goes directly to the primary fuel tank. It is labeled in Blue.

The second hose is a larger diameter and goes to a T. From the T one line continues to the engine and the other goes up towards the primary tank where it leads to another T. From here it branches off and both lines end up into the primary tank.

Any help/ links/ videos of how this all works would be great 🙏🏻

6F498F10-1B32-4157-83B9-FA61DD86A60E.jpeg


513A25EE-CFE1-45C8-B761-1500D15FEC10.jpeg


82873285-EC84-461D-A6B4-F7848ED3474B.jpeg


23FF07E8-BF44-4C11-9370-5B962CED351F.jpeg


03ED49B0-A631-4264-8690-93961623CCF6.jpeg
 
Joined
Jun 5, 2007
Messages
5,253
Location
Brea, Calif.
If you can find your way onto the Downey Off Road link here on mud, you'll discover a copy of the Landcruiser rear fuel tank installation instruction sheets, it shows plumbing for both smog hook up or standard hook up- - -easy deal.
 
Joined
Jul 30, 2019
Messages
200
Location
Orange County
If you can find your way onto the Downey Off Road link here on mud, you'll discover a copy of the Landcruiser rear fuel tank installation instruction sheets, it shows plumbing for both smog hook up or standard hook up- - -easy deal.
Hey Jim ~ Thanks for pointing me in the right direction. I did find the installation guide you were talking about. Cleared up a lot of questions. I still have a few more if you don’t mind.

1) Is this a 22 gal tank? From searching it seems that is the size referenced most.

2) I assume one of the “T”s I have pictured is the “switching valve”? I have 2 “T”s in my system and neither of them are “electric”?

3) It appears that mine is set up for the “Emission System Retrofit plumbing”. Does that look accurate?

4) From the instructions it looks like a fuel pump was not supplied with your kit. Was this left to the end user to purchase? Any info on this would be great.

Thanks for any info!!
 
Joined
Jun 5, 2007
Messages
5,253
Location
Brea, Calif.
What you have is a Con-Ferr 22 gallon rear auxiliary tank. I have no idea where your T's are, or why??? You DO NOT want the system to tie into your emissions system because that forces the rear gas to gravity feed into the front tank, at the same time you are burning rear gas, sooooo you never know how much gas you actually have. It's better/easier to simply plumb where you can use one tank or the other, both having their own sending unit, and you installing a Double Pull-Double Throw (DPDT) switch that switches from front tank to rear tank while at the same time switches from front sending unit to rear sending unit- - -you then can run either tank first, and you will always know how much gas is in either tank. If you opted for a Centroid electronic sending unit in your rear tank make sure you tell them you are running diesel, diesel will read about 5% differently than gas, and Centroid can adjust the values for running diesel- - -easy deal.
 

Users who are viewing this thread

Top Bottom