1996+ Dash Swap into 1992 (OBDI-OBDII)

[willcomsto]

Hey guys, I have been looking for weeks for a reliable how-to on this project, and of the guys that have done it (Miras XJ, MJ Build, etc...) either they took a before and after shot, or the thread is so old that the pictures don't work anymore.

I want to take a dash and all the electrical out of a 98 donor, and swap it into my 92. I know that both had the 4.0l, and both have the AW4, so what issues will I run into with plugging the newer ECU and wiring into the older engine/trans? I plan to use every bit between the firewall and the steering wheel, so there wont be any other old/new connections, just the new ecu to old trans/engine. Also, I will find a pre-99 so I can maintain an engine with a points ignition system, as I assume that a coil over ignition ecu wouldnt recognize a distributor.

As an FYI, I want to use the newer ECU so I can use the newer gauge bezel.

I dont have any issues with mounting it, I know pretty well about the issues with some of the mounting tabs, my question is simply electrical and engine/trans management.

Thanks a ton, this forum rocks!

[4.3LXJ]

Are you swapping engines too?

[willcomsto]

Nope, I want to control my current engine and trans

[willcomsto]

Oh, and as a side note, Once I get this all figured out, I plan to make a very detailed and informative swap build thread for all to see!

[XJ Wheeler]

Oh, and as a side note, Once I get this all figured out, I plan to make a very detailed and informative swap build thread for all to see!

Awesome! Some day... some day...

[willcomsto]

The great part is that I have the dash and all the wiring sitting in my garage, I just want to make sure that the OBDII ecu will control my older drivetrain with little or no issues.

[4.3LXJ]

As you may know, the OBDII stuff is completely digital. The OBDII has different sensors than the OBDI. So to get that ECM to work, you would have to replace all the sensors, throttle body, oil pressure sensor, coolant temp sensor and possibly the cam position sensor. Also, the plug on the OBDII trans have the wires in a different position as the OBDI tranny, so you will have to deal with that also. This is not an easy swap to make

[dagr8tim]

There's a guy on JeepForum who swapped a 97+ dash into a 92 MJ. It was time consuming, but not hard IIRC.

As for the engine, I would want to have the donor and the project side by side. You're going to need the entire wiring harness, all the computers and modules, and everything to make it work. A short cut would be to go to a 5 speed, and you wouldn't have to deal with the transmission computer.

Personally if the 98 has a better engine, I'd swap the OBDI sensors on to it and use it.

[willcomsto]

So I thinnk what I am going to do is to swap out the dash, and make my own gauge cluster with some aftermarket gauges like autometer or something. Tha way I can have the new dash, but keep the old gauges and ECU. I think Ill just sell off the engine management system on Craigslist.

So that being said, does anyone know if just wiring in those aftermarket gauges will work, or do they have to have a dedicated sending unit too? Like with the speedo, can I just take the leads that go to the stock speedo and expect it to be accurate, or is there some kind of intermediate unit that translates the jeep signal into an accurate autometer (or other brand) signal?

Something like this: http://ls1tech.com/forums/attachments/conversions-hybrids/93614-update-mustang-custom-gauge-cluster-dashcomplete.jpg

[4.3LXJ]

If you are going for aftermarket gauges, you will have to use the sending unit that comes with the coolant and oil gauges if they are electric. Those that use a capillary tube have the sensor included. The battery gauge can use existing wiring. Fuel gauges come in two types, full power reads full and full power reads empty. IIRC full power reads full, but you better check applications on that one.

[nickxj94]

Something like this: http://ls1tech.com/forums/attachments/conversions-hybrids/93614-update-mustang-custom-gauge-cluster-dashcomplete.jpg

That's too cool!