Swapping a 5.9L into a 98TJ

    • Re: Swapping a 5.9L into a 98TJ

      Holy CRAP look at all those hoses! I assume there is an engine under there somewhere. :doh: It makes me appreciate my Jeeps OLD SCHOOL technology. :rollsmile:

      I hope you are doing a good write up with lots of pics.
      :spinrhead: ...covfefe... :spinrhead:
    • Re: Swapping a 5.9L into a 98TJ

      I was trying to but when you in and start wrenching the camera is kind of out of site out of mind. All of those hoses were from the 2.5 not that there are any less with the 5.9L but it looks cleaner to me. Also you dont have to deal with combining three wiring harnesses which is a huge job in itself.
      98 TJ 5.9L, RE 4.5 SF, 35s, 4XDoctor Rocker Guards, AA SYE, Tom Woods DS
      2012 JKU 3" lift 35s

      The post was edited 1 time, last by jbates ().

    • Re: Swapping a 5.9L into a 98TJ

      Thats the plan waiting to get the wiring harness back was a little more involved that I had time for had to combine the old engine harness, the new engine harness, and the wiring off of the firewall. Also had the PCM flashed because the 5.9L had an automatic behind it originally and now I am using a manual.
      98 TJ 5.9L, RE 4.5 SF, 35s, 4XDoctor Rocker Guards, AA SYE, Tom Woods DS
      2012 JKU 3" lift 35s
    • Re: Swapping a 5.9L into a 98TJ

      yeah i was thinking about throwing the 5.2 or 5.9 in place of my 97 2.5 but i wanted to use the tj I/P so instead i just got a 2002 4.0 and nv3550. just getting that wired up was a pain...
    • Re: Swapping a 5.9L into a 98TJ

      Got the wiring harness and the PCM in the JEEP. Trying to start it and I cant get it to turn over. I dont think its getting fuel. Does anyone know if the 5.9L requires a higher fuel pressure than the 2.5L?
      98 TJ 5.9L, RE 4.5 SF, 35s, 4XDoctor Rocker Guards, AA SYE, Tom Woods DS
      2012 JKU 3" lift 35s
    • Re: Swapping a 5.9L into a 98TJ

      i would have to guess so since if has twice the cylinders i mean i dont know for sure but that would be my guess.
      bLaTaNt DiSrEgArD<br /><br /><br />TJ 98 4 banger gone but not fogotten<br />WJ 02 limited- Do all vehicle &quot;QUICK THROW A LOCKER AT IT!!!&quot;
    • Re: Swapping a 5.9L into a 98TJ

      omaha wrote:


      i would have to guess so since if has twice the cylinders i mean i dont know for sure but that would be my guess.


      No...you don't need more fuel pressure for more cylinders. Most modern EFI setups should be around 40-50 psi.

      Does the fuel pump prime when you initially turn the key to run? Are you getting a signal from the crank position sensor? Are you getting any MIL's?...does the MIL light even illuminate for a couple seconds at key on to indicate functionality? Either backprobe at the injector or pick up a 'noid' light from pepboys/autozone/whatever for a couple bucks and see if the injectors are firing.

      --Ian (done plenty of engine swaps in imports...)
    • Re: Swapping a 5.9L into a 98TJ

      I cant tell if the fuel pump is priming i dont hear anything. The crank postion sensor is hanging off right now so that might be an issue :shrug: forgot about that cant seem to find exactly where it mounts but then again I only looked for a sec. and yeah the check engine light comes on at key start then goes off. All of the gauges work gas, voltage, oil pressure. I have pressed in the pressure releif valve on the fuel rail and it doesnt seemed to be pressurized.

      Posted on: Today at 11:23:40 AMPosted by: ATRock
      Insert Quote
      what did you have done to the wiring harness? and are you talking about the engine harness from the 5.9 or the 2.5?

      The 5.9l harness, the 2.5l harness and the wiring harness off of the firewall were combined together.
      98 TJ 5.9L, RE 4.5 SF, 35s, 4XDoctor Rocker Guards, AA SYE, Tom Woods DS
      2012 JKU 3" lift 35s

      The post was edited 1 time, last by jbates ().

    • Re: Swapping a 5.9L into a 98TJ

      Check all of your grounds for the harness if they are not all hooked up you will not get any injector pulse . And when you say you cant get it to turn over do you mean it will not crank at all or do you mean it will not start .
      85 cj7 4&quot; suspension 1&quot; body lift on 33X13.50 swampers , Ford 9&quot; / arb , t18 trans , dana 300 t case , and a efi 5.0 from a 93 gt . ( soon to have dana 44 and arb in the front )
    • Re: Swapping a 5.9L into a 98TJ

      Well traced the ground from the fuel pump to find out that the other end wasnt connected. Easy enough to fix. Now the fuel pump kicks in and I have fuel pressure but now there is no spark. All new wires, new plugs, cap and rotor were replaced also. I swapped the coil from my 2.5l engine with the 5.9l still no spark. Also tested the ASD relay it works fine. 20 amp fuse in that line is good also. Not sure what to do now. Any ideas?
      98 TJ 5.9L, RE 4.5 SF, 35s, 4XDoctor Rocker Guards, AA SYE, Tom Woods DS
      2012 JKU 3" lift 35s

      The post was edited 1 time, last by jbates ().