I'm stuck in a hard spot, I swapped my 89 XJ renix 4.0 into a 98 jeep XJ that has wiring for the HO, and the engine is in fine but I'm stuck on the wiring, I started to pull apart the wiring harness from the 89 and it's very complicated. I've seen threads were people swap the renix out for a ho but not the other way around. I'm not sure if I should work with the wiring on the 98 jeep and change out the connectors to make them fit or swap the entire computer over? I just want to get this engine running asap! 1989 Jeep XJ Laredo 4.0 4x4 auto trans and 1998 jeep XJ sport 4.0 4x4 auto trans, the 98 has all manual Windows and locks, thanks for reading!

 

Just use all the 98 stuff on the Renix "long block". Just a reverse of the methods in my write up. Leave the wiring alone.

 

okay, am I supposed to use the HO distributor or renix distributor? And for the flex plate do I use the renix or am I supposed to have the HO flexplate?

 

Use the 98 stuff, all of it except the long block, flex plate, intake and exhaust, distributor, everything. Again, the only part of the 89 you're going to use is the block and head.

 

are you saying use the 89 long block, flex plate, intake and exhaust? Because you said use all except and then you said at the end to use only the block and head??

 

No. Use all your 98 electronics and manifolds, flywheel, and their respective gaskets, on the 89.

 

that's right. Only the block/head. The controls, electronics, everything stay the same

 

I don't think I could have been more clear. Swap the 89 block and cylinder head into the 98. Use the flex plate, intake manifold, exhaust manifold, electronics from the 98. DO NOT CUT AND SPLICE THE WIRING HARNESS TO MAKE THE 89 SENSORS WORK WITH THE 98 HARNESS!!!

 

so that means I gotta buy a flex plate and manifolds for the 98, I bought the 98 jeep with no engine and tranny

 

If you want it to run yes.

 

That woulda been nice to know right up front....................

 

Now u ll need to find a 98 dizzy, manifolds, throttle body, wiring, flex plate, etc. and I bet u probably ll need to find a 97-01 transmission too because it is wired up differently from a renix transmission.

 

oh and since u are only using the block itself, u ll need to get 98 accessories such as alternator, power steering pump, etc

 

the only thing the 1998 jeep doesn't have is the engine and transmission, it has the power steering, alternator, ac pump, I'm curious to why is the reason I would have to get a new flex plate? I'm still learning a lot about these jeeps and an engine swap isn't something I've done before.

 

renix flex plate read signals differently because it is controlled by completely different computer system