No announcement yet.

2003 Wrangler R2.8 Build

  • Filter
  • Time
  • Show
Clear All
new posts

  • 2003 Wrangler R2.8 Build

    I'm hoping to solve some issue with this post. Just got my R2.8 running. Very impressive power. I'm running the 5-speed manual transmission and I integrated a GMC clutch that has the Jeep splines, onto the Cummins flywheel. Modeled and built my own bell housing - no adapters.
    My issue is utilizing as much of the Jeep dash as possible. I need a speedo/odo and a fuel gauge. The other engine monitoring comes off of the Murphy readout. I have left all of my Jeep OEM computers connected with the Jeep engine obviously missing.
    Has anyone figured out how to make the fuel and odo/speedo to work without an engine?

  • #2
    As for the required items, I believe you need the stock ECM to run the stock guages. Normal recommendation is to replace with an aftermarket version.
    Im sure there is a way to make them work but being I am not an electrical engineer I cannot say how.

    Post some photos of your bellhousing if you don’t mind!


    • #3
      I have the stock ECM still powered. Just no Jeep motor attached to it. Below is a photo of my bell housing. It mates the R2.8 to the Jeep 5-speed. Fabricated and machined. No adapters needed. It uses the Jeep hydraulic clutch slave and throw-out.


      • #4
        That looks great. I love seeing that level of custom DIY work. I have trouble when I do that because I have the tendency to over analyze and not get much done and my Jeep is my daily driver. So when I got ready to order the Engine I had to budget paying for basically everything else and I'd just be the labor.

        I decided recently to switch to aftermarket gauges and I'm running a 97. When I was researching to keep the stock gauges, I heard that you had to "excite" the cam sensor to get the PCM to stay powered on. I never confirmed any of this, but I was told the crank position sensor, located at the front of the AX-15 bellhousing would read the RPMs to the PCM. I know that's probably not much help, but I have heard that however your OEM jeep read the RPMs, that you had to excite the cam position sensor. I've also been told every year was different.

        I talked with another buddy of mine with a lot more controls experience and he plays around with wiring drones and making custom chipsets for that kind of stuff. He suggested just making a custom sensor converter and driver for the actual needles in the panel with like with Arduino or something, but this sounded like way too much work to me.

        Personally I'm a bit lazy in some respects and wouldn't care too much to just use my phone/GPS for speed, RPMs and lights, like low oil pressure and toggle for Temp off of the the Murphy gauge, and a DMM to measure the resistance off the OEM Jeep Fuel level sensor. However I did just decide to wire in a Dakota Digital Dash/gauge set, that will probably be a work in progress until next year.


        • #5
          How did you power the in-cab power lead? Did you find an ignition wire to splice into?


          • #6
            Victorino, were you asking me for the Cummins ECU wiring?

            If you were I used the Dark Blue wire running to the ignition switch (after a couple of tries, the run position won't work for starting). The wire I that I used is energized when the ignition is in the start and run position of the ignition switch.