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88 4.0L Renix to 96 4.0L HO swap...full swap?

swommack2

NAXJA Forum User
Location
Texas
Ok so I've searched, read, and researched longer than most do and can't seem to find what I'm looking for. I've got an '88 XJ Limited 4x4 with 4.0L inline 6, AX4 tranny, and NP242 transfer case. Long story short, the head gasket is blown and most likely cracked head. I picked up a '96 complete drivetrain for a pretty good price. The engine wiring harness and ECU are included. I want to do a complete swap to have every benefit from the HO and newer AW4 and NP231. Everything I've read says to use parts from this and the sensors and intake manifold from my 88. But that's not gonna give the full benefits of the HO...as I understand it. Is it possible to swap everything into my rig, including wiring harness and ECU? I was also thinking of swap in the dash harness and instrument cluster as well as the TCU from the donor (if it's needed).
Sorry for the long post but I wanted to give as much info as possible. As it stands, my rig has ALOT of upgrades including a brand new TrailMaster 4.5" lift with full leaf springs, 33" Dick Cepek MT, rebuilt Ford 8.8 rear end with 4.10 gear ratio and Limited slip diff, and winch bumper, front and back,just to mention a few. I've also demolished the interior and upgraded to WJ seats. The backs seat and all carpet has been removed to do a custom build for camping/bug out buggy set up. This is my first Jeep and I fell head over heals in love the first time I laid eyes on her. Can anyone help me accomplish my goals or will I be paving new roads for future Jeepers that have an obsession with their XJ?
 
Converting a renix system to obd2 is to much work for what little rewards there are and with a renix reader the differences are even smaller.
While I love my 96 there is no way I would convert my 89 to obd2.
 
Converting a renix system to obd2 is to much work for what little rewards there are and with a renix reader the differences are even smaller.
While I love my 96 there is no way I would convert my 89 to obd2.

exactly right^^

2 things the OP needs to read:

HO myth buster


Renix in 90 made 182 HP. HO in 91 made 190 HP. That's 8 HP difference.

HO only made more HP than Renix at higher RPMs and not a bit more torque. HO had a 58 mm throttle body versus a 52 mm throttle body on a Renix. That’s 20% more air available through the HO throttle body. The HO also had a better design header. See where I'm going with this?

It’s only a 4% horsepower increase…..

The whole 8HP was not mostly from the head, but from the bigger TB and better exhaust manifold.

Put a 60mm TB from www.strokedjeep.com on your present manifold using the Renix head, eliminate the "crush" in your headpipe with proper re-routing, and go for it.

HO stands for Highly Overrated.
__________________
http://cruiser54.com/?p=100
 
Listen to cruiser.
I have bored TB on both my heeps.
Also consider finding a late-89/90 PCM. There is info on PN for them somewhere.
 
I think the renix sensor swap is for putting a HO engine in a renix jeep.

If the OP has everything from a 96 including the engine he could just remove all the renix engine and wiring and put in the 96 components.

If the renix electronics are ok its probably not going to be a huge befit getting OBDII,
Also keep in mind 96 is the first OBDII XJ a lot one one year only components but nothing I can think of to trip you up.



Sent from my iPhone using Tapatalk
 
I think the renix sensor swap is for putting a HO engine in a renix jeep.

If the OP has everything from a 96 including the engine he could just remove all the renix engine and wiring and put in the 96 components.

If the renix electronics are ok its probably not going to be a huge befit getting OBDII,
Also keep in mind 96 is the first OBDII XJ a lot one one year only components but nothing I can think of to trip you up.


Lotsa work for no gain.
Sent from my iPhone using Tapatalk
 
First of all I'd like to thank everyone for the valuable information. Going by the manufacture date on the PCM I got with the engine, this is actually a 1993. That means it's not OBD2 and also means that the information I got from the seller was incorrect. Hopefully everything functions as reported.
Anyhow, I also wanted to add that I've already swapped over to an open coolant system and external trans cooler.
Upgrading to a bored out throttle body sounds like a smart move. I'll certainly check into that.
On another note I'd like to add that one reason for wanting to do this swap is that I had a small electrical fire last year after running thru the surf in Corpus Christi and not rinsing the salt water off immediately. The fire fried the alternator, starter, and a good bit of the wiring harness. After careful inspection I realized the fire was likely due to exposed wiring causing an arc. I did my best to repair/replace the damaged wiring harness but am not 100% happy with the results. Figured since I had the new harness, I can upgrade to a much better looking OEM set. Before installation I'll be going over the electrical components and wiring to ensure good contact points and no exposed wiring.
Anyone have anymore suggestions while I've got everything tore apart?
 
First of all I'd like to thank everyone for the valuable information. Going by the manufacture date on the PCM I got with the engine, this is actually a 1993. That means it's not OBD2 and also means that the information I got from the seller was incorrect. Hopefully everything functions as reported.
Anyhow, I also wanted to add that I've already swapped over to an open coolant system and external trans cooler.
Upgrading to a bored out throttle body sounds like a smart move. I'll certainly check into that.
On another note I'd like to add that one reason for wanting to do this swap is that I had a small electrical fire last year after running thru the surf in Corpus Christi and not rinsing the salt water off immediately. The fire fried the alternator, starter, and a good bit of the wiring harness. After careful inspection I realized the fire was likely due to exposed wiring causing an arc. I did my best to repair/replace the damaged wiring harness but am not 100% happy with the results. Figured since I had the new harness, I can upgrade to a much better looking OEM set. Before installation I'll be going over the electrical components and wiring to ensure good contact points and no exposed wiring.
Anyone have anymore suggestions while I've got everything tore apart?
 
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