motor upgrade

I have a 90 XJ 4.0l auto with some issues. I'm tired of messing with it so I picked up a 2003/04 motor tranny & t/case with slip yoke eliminator already installed already bolted together as a combo. (32,000 k's, yes :canada: canadian, lol)

Anybody know what is involved in this swap? I know the wiring will obviously be an issue, but can anybody tell me more about motor/tranny/t-case mounts? Fuel pump requirements?

Any recomendations or advice greatly appreciated:helpme:

please & thanks
Paul

What model Jeep is the combo out of?

Edit: I guess it has to be out of a Wrangler? Or did the Grand still have the 4.0 in '03?

cherokee, I have all the acc brackets, etc.

edit. may be an 02, I know it was out of a Cherokee as all the brackets are correct, and it has the distributerless ign of a late model. I actually bought it thinking it was the TJ motor, but had a talk with somebody whom knew of the motor and had the actual brackets (they been been changed over to the TJ for a CJ project that has been scrapped)

Uhhh, there was no '02 XJ.

Last one was in '01.

So if it's an '02 Cherokee, it's from an '02 Grand Cherokee.

guess I'll grab the block ID to confirm?? crap, sorry to be a bother. be back in a few days, I'll stop wasting time here.

so if it is a 01, do you know if the motor/tranny/t-case mounts line up??????

If it came from a grand, i'm sure it is not an aw4. The mount location on that, and how long it is might have an affect.

the tranny is deffinatly an AW4. I'm presuming I'm off on the year

Your best bet is to take the head off of your 90, get a quick valve job done, put it on the 01 block, and run that block with your 1990 head, wiring, intake, exhaust, trans, and transfercase.

Its going to be less work than getting all of the 01 intake/exhaust, smog, wiring, and then getting the vehicle recertified for 2001 emissions.

In B.C. we do have aircare but I'm not worried about that, we have ways, lol. I am going ahead with a complete swap. I have some broken exaust bolts in the 90 head. It's what started the whole thought process. Also has 350,xxx plus kilometers on it. We are going ahead with all the wiring etc... everything other than dash/interior, and light wiring will be replaced to 2001 spec. I drive approx 150+ k's everyday for work and the newer stuff I'm led to believe has better mileage and performance.

I am going to go after market fuel pump (Edlebrock??) any other advice??


I do appreciate the responses so far, this is by FAR the most knowledgeable group I've found.

The renix (what you have now) gets better MPG than the late model ones. The late model does have a little more power, but at the cost of mileage. My 87 got 25 mpg stock and gets 19 mpg on 35's.

If you intend to tackle this, make sure you have both rigs, sitting side by side. You will have to swap *EVERYTHING*. Wiring harnesses, computers, plugs, sensors, vacume systems, accessories..

You're going to gain a few horsepower, but you'd get that just swapping the block.

hmm, some thinking will be required....

I have an extremely capable tech to do the swap that would be sure to get everything right, no worries there. But you have now possibly made it easy enough that I could do it myself....

So the motor mounts, and tranny mounts, etc... will be the same??

If it came from a cherokee yes. (thats assuming of course your 1990 was an automatic).

Nothing else is the same though. I seriously mean you want to have both vehicles side by side to do the swap. Relay boxes, fuse panels..

The 90 has a knock sensor in the block on the drivers side toward the front near the oil pan. The new block you have likely does not have a hole for it. There were a few years where the hole was plugged.
The ignition system is likely coil over spark which is a huge difference and will not be compatable with the Renix ECM.
The MAP sensor is on the TB not the firewall adaptation will be requried.
The intake manifold does not accommidate the EGR componants on the Renix system
The TCU is likely different and you may need to use the existing one.
Cooling is different. you may want to "upgrade" to an open system.
The thermal sensors are different and you will need to use the Renix approach.
This list is just off-the-cuff. I am sure there are other issues as well like the vacuum plumbing differences.

BTW the fuel pump is in the tank. I would keep the injectors that came with the engine, but the fuel rail was differenet and you may have to use the Renix fuel rail and possible buy an adjustable pressure regulator. Crap, stuff keeps coming up! I'm going to quit now and just say do a "search", I am sure this has been covered before.

Well we're going ahead with the complete swap on the 29th. All wiring from the firewall forward will be replaced (other than dash comtrols and lights) I'll keep ya'll posted how it turns out.

Well I finally got it back on the road, been a long haul. About 6-700 miles and no real hiccups, looks good. We kept my old fuel rail so I can still use the old style pump (which I need to still replace, it's getting tired). Also still need to hook my electric fan up, going to make it automatic yet still have a manual overide switch, and my low fuel light only comes on when it's full:laugh2: I also took out my transfer case drop which gave me an extra inch clearance.

One thing we didn't get to was the Tach, we can't find a signal to hook to the dash. I upgraded to the 95-98? era dash, so it is electronic speed control (no speedo cable) and all my gauges are working except my Tach. And I also need to find a overflow bottle my cranberry bottle will only last so long, lol.

Wow, what a difference the power is, so much more responsive, I love it!!

Cheers from BC:canada:

ps, I can't figure out how to post pics, if you would like I could email them to somebody???