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Fuel injected 258

Discussion in 'Intermediate CJ-5/6/7/8' started by CJ-X, Nov 22, 2008.

  1. CJ-X

    CJ-X Member

    I have a friend who says he has a 258 in his 1987 wrangler. So, am I correct in assuming that the '87 YJ had the same version of 258 that the cj's did?

    If so, or even if not so; Is there a simple junkyard conversion for fuel injection for this engine? I have done my own fuelie conversions, so I know what it takes, but what I do not know is if there is a donor engine that I could steel the throttle body and distributor off of.

    Any suggestions?
     
  2. 4S50

    4S50 I’m back!

    Howell markets a TBI kit for these engines that uses GM 4.3 V6 components.
     
  3. hudsonhawk

    hudsonhawk Well-Known Member

    :iagree: Or if you are adventurous you can build your own using a junk yard GM TBI and a megasquirt controller.
     
  4. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    You an use the GM computer if yo are willing to burn a chip to work with the 258. That's basically what the Howell kit is - stripped-down 4.3L TBI with a custom chip.

    There are lots of articles online if you search ... for example, this: http://www.bustedjeep.com/projects/junkyardtbi.asp
     
  5. Kman

    Kman Member

    You could also swap in 4.0 components. Use a 4.0 head, intake, exhaust, dist and flywheel and modify a Wrangler or Cherokee harness and computer.
     
  6. all4jpn

    all4jpn Member

    like kman said,,,,,,cherokees are cheap on craigslist,,,get the head ,swap that and the fuel injection,,,,,been done a thousand times
     
  7. 73cj5

    73cj5 Member

    or just swap the whole engine from the cherokee
     
  8. CJ-X

    CJ-X Member

    Head from a 4.0. I guess that is what I am looking for. I haven't really paid much attention to all the 6cyl post over the years.
    Kman, you said also get the flywheel. Is that because of a crank position sensor?
    Also any particular years required for the swap?
     
  9. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    You want the '91-on "HO" version. My notes say "Head casting # 7120" though I recall that there is a later head that is also acceptable. This may be helpful http://www.jeepstrokers.com/forum/viewtopic.php?f=15&t=375

    If you want the MPI, it may be cheaper to look for a complete XJ as a donor. They are unibody cars, and rusty examples can sometimes be found very cheaply.

    The CPS can go on the flywheel (factory location) or on the front at the harmonic damper. To put it on the front, you'll need a kit from HESCO or Advance Adapters (?). To put it on the flywheel, you'll need the 4.0L flywheel and to modify your bellhousing to accept the sensor.
     
  10. High5

    High5 Member

    I did the Affordable fuel injection conversion on my 258. Works great. Way better than carb, with throttle response, cold starts, and power.

    I would like to convert to a 4.0 head at some point when I'm ready to change the exhaust to something quieter.

    Good luck

    High5
     
  11. 4S50

    4S50 I’m back!

    I am running a 7120 head and the Mopar MPI on my 4.2 block and am real happy with it and recommend it. I did the MPI before I did the head swap and the HO 4.0 head really woke it up and I now run regular gas without pinging.