New heart for TJ

Good day all, have a question regarding an engine and tranny swap. I have a 97 tj 4 cylinder with ax5 and 231 t case. Also have a 93 zj straight 6 auto and 241 t case. Going to put 6 and auto in the tj. To go ahead and answer the obvious, I am an experienced fabricator, and a gear head. The question I have is what hiccups might I run into with electronics and wiring, gauge cluster and the like. Thank you in advance. And I used to be a toyota guy, my wife brought me over to the dark side.

 

Welcome to the family from ny sounds like your ganna have a fun time with the swap. I'm not much help hopfully someone else will chim in soon like @Prerunner1982 or @Awrench, @aggrex

 

Thank you for the welcome and the bump, sorry for the short and sweet post. I have looked at a bunch of other swap threads, didnt find the particulars of the electrical side of things.

 

Welcome @32peapicker1 ...interesting project. Fabricator+gearhead are great skills that might be needed for that conversion for example the motor mounts are a typical issue for the novice. Check out Novak-adapt.com for info on similar conversions. Best to obtain the ECU, harness, etc in addition to the motor, trans, etc from the donor vehicle.

 

Thank you, being new to keeps I don't know where the info is. Will give Novak a look. And I have the whole zj so parts will not be an issue, well except for drive shafts.

 

When it's time for drive shafts the jeep world is ready with Tom Woods or Adams who will custom build them for your application

 

Thank you, yes, I found addams while building my xj, very good company.

 

Very similar to what I will be doing with my old CJ.....the same exact engine/trans. Keep the PCMs together with their respective engines/trans...the 4 cyl. Brain will not run the 4.0.

One huge advantage is the OBD I system as they are much simpler than the later OBD II, and work just as well. Also, as I understand it, the engine and trans have separate control modules, simplifying hookup. I’m not sure if the body electronics will need to talk to the PCMs, but I don’t think so....I haven’t run across anything that says it will matter, especially to the power train.

Another bonus of the ‘95 and older ZJs is they have the most potent 4.0 due to the cylinder head—yours should have “7120” cast into it at the mating surface, driver’s side, dead center between #3 and #4 cylinders. It’s a the best head of the three iterations put on the 4.0.

 

Picking up the zj this week, I will definitely share which cylinder head it has, thank you for the information!

 

The potential problem I see is trying to mate a OBD1 engine management system into an OBD2 vehicle, mainly the interior.
But..... I have never done a 4 Cylinder OBD2 to 6 cylinder OBD1 swap so I can't speak from experience... it doesn't sound fun.

I have swapped an OBD2 engine into an OBD1 vehicle but it was a 6 cylinder for a 6 cylinder so it didn't really require anything other than swapping the sensors over.
I am planning on swapping the HVAC box from my 97 XJ (OBD2) to my 93 (OBD1) non A/C XJ and it's going to be a "fun" project.

 

Worst case scenario is having to change out the gauge cluster and body harness I think, i will keep this thread updated as to what i run into.