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Electric fuel pump conversion

Discussion in 'Daihatsu Hi jet' started by jody, Feb 2, 2015.

  1. jody

    jody Member

    Hi again.. I have read a couple of threads on converting to an electric fuel pump but just wanted to see if anybody has done it to a Hi-Jet. Mine is a 93 S83P with a mechanical fuel pump. I have replaced it twice already and they only seem to last me a year each. I want to change to an electric pump. What I have read says I need to install a fuel regulator. Just wanted to check an see if it is really needed. Also any info that you could provide me in the installation would be greatly appreciated. What parts to purchase and installation tips would be helpful.
    Thanks for your help.
    Jody
     
    mdh71 likes this.
  2. TRAX and HORNS

    TRAX and HORNS Well-Known Member

    I added a aftermarket 2psi-4psi fuel pump to a Honda not long ago. The oem electric pump went out and I could not see paying the crazy ass price for a new oen pump. It worked out great. I think I paid 49.95 from ebay. I would assume you could do the same thing. Mount back by fuel tank with a inline filter and bypass the mech. pump.
     
  3. patrino

    patrino New Member

    Just did an electric inline-pump conversion on my 660cc Kia MicroTruk. Works great. $50 at AutoZone for the pump. Used a pump for an '80s carbureted Dodge Omni (the parts guy needed a reference vehicle to find the right pump). Like TRAX and HORNS, plumbed it inline. Fuel tank --> Fuel filter --> Fuel pump --> Carburetor. The pump's just a bit bigger than the fuel filter and came with a mounting clamp; I just attached it to the frame rail.
     
    Juju1187 likes this.
  4. jody

    jody Member

    Well I got my fuel pump hooked up and I just plumbed it into the old mechanical pump. It seemed to work but now it's warmer and I want to just bypass the mechanical pump and get things right. What do I do about the return line? Any suggestions or help would be greatly appreciated.
    Thanks
    Jody
     
  5. patrino

    patrino New Member

    Jody, not sure about the return line. What do you mean?

    Did the instructions that came with the fuel pump say anything about plumbing it through the mechanical pump? I don't have my instructions in front of me but seem to recall that routing it from the electric pump through the mechanical pump can cause premature pump failure. I'll see if I kept the details when I'm down at my shop tonight.
     
  6. jody

    jody Member

    Hi Patrino
    No instructions came with the fuel pump. It's just your basic electric low pressure pump. I'm sure I need to do something with the return line. I'm hoping someone has done this mod and will offer some insight. Thanks for getting back to me.
    Jody
     
  7. Tori Bean

    Tori Bean New Member

    I have an electric fuel pump installed, with a 1-6psi regulator. Right now I only have it set to 1psi. Im worried this is too lean....what is yours set to & how does it run?
     
  8. fmartin_gila

    fmartin_gila Well-Known Member

    Tori Bean - try 2 to 2 1/2 setting on the regulator. Jody - Take off the return line and tee it into the line you are drawing from between the tank and the pump so it will return to the intake side of the elect pump.

    Fred
     
    Juju1187 likes this.
  9. Tony Evers

    Tony Evers Active Member

    Fred
    your a wealth of information, Thank you for making this site as good as it is
     
  10. Tori Bean

    Tori Bean New Member

    Turned up the regulator to 2 today, and after playing around with the carb for awhile...got it running even better than it was before. Its smoother, and even a bit quieter than before!!
     
    Juju1187 and Tony Evers like this.
  11. Hap Wilson

    Hap Wilson Member

    Just a quick question because I am also considering doing this upgrade to mine. Is there any benefit to running the return line to the intake before the electric fuel pump instead of back to the tank or? Just wondering as I am learning more and more about carb's everyday haha
     
  12. fmartin_gila

    fmartin_gila Well-Known Member

    Have not heard any feedback but after studying the diagram that I have available, I don't think you have to do anything with the return line as it already returns the excess from the carb directly back to the tank. This was the style fuel system used by some of the Jap manufacturers back during the 60s & 70s and some on up till they went EFI. I did not have this diagram available to me back then and apologize if I may have given bad info.

    As a safety measure, when replacing a mechanical pump which is mounted to the engine block, it is best to fully remove the mechanical pump & fabricate a metal plate & gasket to block off the hole or if you don't remove the pump at least loop a length of fuel hose from inlet to outlet just as a precaution if the diaphram ever blows it will not leak engine oil out the pump. It is best not to push gas thru a mechanical pump with an electric pump because if the diaphram ever blows, it will fill the oil pan with gas and can cause a fire or explosion. SAFETY FIRST!!

    Fred
     
    Last edited: Nov 28, 2021
    Limestone likes this.
  13. bobjonah

    bobjonah Active Member

    If you do not want to make a blanking plate, you can just remove the push to disable it, and leave it in place.
     
  14. Hap Wilson

    Hap Wilson Member

    Sounds about right I think I will install an in-line electric and set it about 2psi, and purchase a block off. Or, I could even leave the mechanical as a backup on the truck.
     
  15. fmartin_gila

    fmartin_gila Well-Known Member

    That is a questionable good point, if you do leave the pump in place do loop inlet & outlet so it will only pump a bit of air back to itself but be aware that it will continue to wear with each mile accumulated and may or may not work when you need it. Just for consideration.

    Keep in mind that mechanical pumps suck best and electrics push best, so if you do install one, mount it close to the tank.

    Fred
     
    Last edited: Nov 30, 2021

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