1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Your opinions on FI

Discussion in 'Intermediate CJ-5/6/7/8' started by 72CJ5er, Apr 30, 2006.

  1. Apr 30, 2006
    72CJ5er

    72CJ5er Renegade Member

    Hampton, TN
    Joined:
    Mar 31, 2004
    Messages:
    151
    OK,

    I have an idea to try and retrofit a YJ fuel injection to my 258 I6. what I am meaning is the central fuel unit and fabbing an adapter to get it to mount on the intake manifold.

    am I nuts or does this sound plausible.

    I already have all the stuff here its just do I try it and didnt know if it may have ever been tried before.thx
     
  2. May 1, 2006
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    20,579
    You mean the Mopar MPI? It's been done many times, but if the donor is a 4.0L, a head swap is the best route. The 4.0L HO head flows much better than the 258 head.

    If this is TBI from a 2.5L, I expect the throttle body will be too small. You'd be better off scrounging the parts from a GM 4.3L and burning your own PROM (or flash memory).
     
  3. May 1, 2006
    72CJ5er

    72CJ5er Renegade Member

    Hampton, TN
    Joined:
    Mar 31, 2004
    Messages:
    151
    Yes the donor is the 2.5 4, I was thinking along the lines that the 4cyls MPI would be less cfm equaling to that of a small jetted carb giving better overall MPG. Im not worried about HP on this one, just a better fuel economy and trail use without bogging due to angle tilt problems that plague the carbs. I should be able to modify an adapter out of another adpter I have, it fits the manifold I currently have and the holes are off only slight, I have access to a mill that I can use to fix that.

    I just thought since I had it all in hand I know I can get it on there, its just a wonder if anyone has done a swap. I need to know what all I need. I know from past experience all I needed to FI my Mustang was a FI harness that attached the unit up to the computer, and the fuel pump to drive the injectors. Im just wondering if I can graft out the harness for the FI out of the rest of the 89s harness w/o having to use the whole thing. and in the end is it worth it.
     
  4. May 1, 2006
    mb82

    mb82 I feel great!

    Charlottesville Va
    Joined:
    Mar 17, 2003
    Messages:
    2,715
    I don't think the 2.5L FI will work very well on a 4.2L motor, just not enough fuel. Also I don't know if the 4cyl FI system will work on a 6cyl motor.
     
  5. May 1, 2006
    MCSCOTT

    MCSCOTT Member

    Columbia, Tn
    Joined:
    Apr 24, 2006
    Messages:
    909
    :iagree:

    If you do decide to do it and it works, let us know what all is involved in the swap. I don't have any experience in this particular swap but I know that if you can go to FI it is definately worth the effort.
     

Share This Page

New Posts