Zander's Bio Diesel Conversion Page

1985 Toyota BJ70 diesel (Canadian Spec.)

Since these are older diesels with non modern plastic fuel lines, I wanted to swap these for a more compatable plastic. Most modern diesels (like my old 97 Dodge, and my fiance's 2000 VW) dont need to anything like this. In making this vehicle compatible for Bio Diesel I searched around online and found some folks in the forum who were already running the Toyota 3B diesel motor on Bio Diesel. They had swapped over their fuel lines to a modern compatible material from the old natural rubber hoses. I chose to go with the best material available, Viton hose from (5/16" ID, 9/16" OD, 1/8" Wall - p#5119K51). I used about 5.5 feet of the Viton hose and the (somewhat messy) job, including new fuel filter and re-priming, took about an hour (my Hj60 only needed 3 feet). Pretty simple job, I would recommend downloading the 3B or 2H motor manual from to get the basics of repriming etc, if you havent done it before. The fuel line system is made up of several segments of hard steel and soft rubber line. You only need to replace the rubber components. I have included pictures below of these sections of line. I have now done this conversion to all my 1980's Toyotas and it is basically the same on all.

I ordered 7 feet of hose (about $100) in case I miscut. I had a catch basin to catch fuel, I wore gloves and the only other tools I needed were a razor blade, a pair of scissors, and a zip tie. It is recommended that you do this with a mostly empty tank to reduce the siphoning pressure on the system. The fuel will mostly drain from the tank side of the first piece you remove, so starting with that one will make the rest easier. (This one is also the most difficult to access as its up on top of the tank.) Starting with the rear most line I held the line up next to the piece I was going to replace to measure it, and cut the new line to length. When you pull this one you can fold it over and zip tie it to itself to stop it from draining and come back to it last. Some of the lines required me to use the razor to slice the end a bit to get it to release from the metal line.

Once each section was done dripping more or less I went on to the next section and started replacing lines one by one putting the clamps back on the each new section as I went. The pictures below shows examples of the different segments. In each case some fuel drips down when you pull the lines, so you should watch out as you are working over your head and keep a catch basin and paper towels at hand (I wore glasses too). I replaced the tank line that I had blocked off with the zip tie last allowing fuel back into the system.

Once this was all done I re-primed the system just like I would after replacing the fuel filter and filled it up with Bio Diesel I started it up and its been running great ever since!

(The pictures below have the fuel lines highlighted for better clarity)

Fuel line going into the fuel pump in the engine compartment.


Fuel lines at the water separator in the engine compartment. Note these have insulation hoses on them that should be moved over to your new hoses.


Fuel line along the chassis under the vehicle.


Other fuel line along the chassis under the vehicle.


Fuel line at the tank under the the vehicle in rear.