Renix

SLO_MVR · 07-25-2008, 07:39 AM

I hate to do this, but apparently me and the search function don't get along so well.

I recently got my old 2.5 yj back from my younger brother who blew the engine up and swapped a 4.0l back in. The harness from the 4.0l looked like a spaghetti buffet. Obviously, he's not good at wiring. The engine would crank, fire, and spray fuel. I haven't put any time at all in trying to piece the harness back together myself. He's not much of a mechanic, but I've built race cars, late model EFI conversions, etc... So I think I'm a little better off w/ the electronics than most folks.

The current engine/tranny in the yj is a 4.0 w/ 5spd. I do not know the origin of the engine yet. I haven't had an opportunity to run the numbers. What I do have, is a donor 4.0/auto combo from an 87 wagoneer. The current owner claims the computer is shot. This is the 173hp Renix version. I've heard all of the Renix war stories and so I have a decision to make. Fix the wiring and keep the current stuff, or switch to the 4.0/at stuff. Personally, I would rather have the auto trans, but at what risk w/ the Renix?

My questions, will the 87 AW4 bolt up to any other 4.0 (Renix or not)? I do know that the Renix is the ECM and not necessarily and hard parts. Will the AW4 fit all years (post '96) or is it limited?

Secondly, if the auto from the Wagoneer will not bolt up to what ever current I6 is in the jeep, would you folks with experience rather swap everything from the Wagoneer over, or fix whats in the jeep now. The qualifier for this question is whether or not the Renix is trouble, or not.

Trash it and buy an I6 equipped jeep is not an option. I sold the jeep to my brother for $2k and bought it for $500. I added shackles, BDS lift, quick disconnects, new bestop, aux lighting, wheels, tires and other misc crap to it long before I sold it to my brother. For all of the parts on it, it's going to be much less an investment to get this thing on....errr off the road rather.

Thanks for all your help guys/gals.

**Brown Dog** · 07-25-2008, 09:33 AM

First things first. Fill out your profile so we can intelligently help you.

dukegnarley · 07-25-2008, 10:01 AM

the aw4 was used all the way up to 2001. I have a '99 aw4 (physicall) hooked up to a '90 renix. If you run a renix engine you'll need the transmission computer from that year range as well. the tps from the renix engine gives off the inverse signal from the one on an HO engine. if that makes sense. I'm skipping the automatic function of the aw4 and just electronically shifting mine.

SLO_MVR · 07-25-2008, 11:50 AM

Brown Dog: Thanks for the subtle reminder to update my profile, I forgot that. However, the content of my post included plenty of information for someone to make an informed/intelligent response.

Duke: Thanks for the input. Right now, I have the 93 yj sitting with a 4.0l, 5spd manual, and t-case from (so far) an unknown origin sitting in the driveway. The harness was unwrapped and "trimmed" when my brother put the engine in it. It has been sitting for about 30 months in it's current state.
I have also an 87 wagoneer w/ the 4.0, auto tranny and every nut, bolt, and wire attached. The drivetrain in the 87 is free to me to remove and do with as I please. The owner is scrapping it otherwise. He was told that the computer is toast in it.

On one hand, I could spend hours re-wiring what's in the yj now. Or probably the same or less amount of time putting the 87 drivetrain in 'er. I'm torn...

You make an interesting point about using the renix engine w/ a non-renix tranny being an issue, but would there be an issue using the tranny from the renix equipped jeep behind a non-renix 4.0?

Anyway, I'm going to pull the drive train from the 87 before it goes to the crusher anyway. I'll get the yj towed home this weekend and see if the wiring is really as bad as I remember it. I'll find out what year and platform it came from and maybe a new harness is the best answer.

Thanks again folks.

dukegnarley · 07-25-2008, 01:45 PM

If the engine currently in the yj is non-renix, then i'd rewire it and keep it assuming it's in good shape. the transmission behind the renix engine will work behind the non-renix (HO) engine. the thing you'd need to do is grab a transmission computer from an ho engine so it reads the tps properly. I got one off of ebay for $40 a while back. as far as i know the aw4 didn't have any changes through the years, but the computer for it did.

wendell · 07-26-2008, 06:32 AM

The renix isn't that bad, I wouldn't sweat using it if you have to.

SLO_MVR · 08-15-2008, 07:22 AM

So I'm a couple of weeks behind scheudle. I have the new ('87, 82k) 4.0 w/ the harness complete, in my warehouse and ready for the swap. I decided to leave the trans and t-case in the jeep. I'll contend w/ the auto swap some other time. The priority is to get this bugger running again. I'm picking the Jeep up tonight and tomorrow will trailer it to my shop and get busy. The new replacement engine has the harness and everything complete and ready to go.

All I need that I am aware of is to pull the flexplate from the new engine and put the (brand new) clutch and flywheel from the old engine in its place. Oh... I do need to pick up a new pilot bearing.

Am I missing anything?

I'll be sure to take plenty of pics during the process.

wendell · 08-15-2008, 08:09 AM

I just read an aricle in an old copy of jp mag that said they never put a good auto trans in a wrangler. They recomended swapping in a AW4 automatic. I never had any problems with my renix equiped jeeps and jp mag also confirmed this by saying that the renix system is a good system, just not as performance oriented as the chrysler. With this in mind, I would have no problem using the renix if need be. I would go a head and swap in the AW4 and renix engine and you would know excatly what you have. The wrangler will perform every bit as good as a 258 with the howell conversion and you will have the good AW4 auto to boot.