Motor swap help

Ok I have a 93' cherokee with the 4.0, the motor, trany and transfer case all went on me over the course of a week. So i found a new compleate motor, trans, and transfer case out of a 2000 jeep with 40k on it and i got a great deal the whole thing for $350. But the problem is that the 2000 motor is not the exact same, for one it has the coil pack instead of a distributor. Does the cam still have the distributor gear on it because if so i should just be able to use my old distributor. I am also wondering if any of the wireing changed significantly. Now i am experienced and im a mechanic, i just want to have some idea of what im in for when i start this on the weekend. Some one out there has had to of done this before, but searching found nothing. Thanks

Not sure about the motor but if you have an AW4, there are different
sensors on the later one. Maybe you should use the computer and wire
harness out of the 2000 and keep the coil packs.

JXPEEJ said:

Not sure about the motor but if you have an AW4, there are different
sensors on the later one. Maybe you should use the computer and wire
harness out of the 2000 and keep the coil packs.

Click to expand...

Elaborating a little more on what he said. You can use a dizzy in the later model 4.0s, the hole is still there. Now what distributor exactly, I'm not sure. I would use one from a 99 since that is the closest possible. I forget why the transmission won't bolt up but there is something in the tailhousing I believe that may have to do with a speed sensor(?) that is different. I believe you have to gut both transmissions and trade something from one to another. If I were you, I would do what I'm doing and put the entire wiring harness in from the later model year and gain the new dash with airbags and such. I understand it's a little more work but in the end it might almost be easier than messing with timing and ripping 2 trannys apart. Hope some of this info helps.
-Collin

Well the first thing you should know is that the wiring changed in 1997 to a multiplex wiring system. The harness will not match up with your dash. And if you don't have the harness then you have another problem. First things first get an engine wiring harness. Then I'm sure you could find a way to tie it into your dash(maybe :dunno: ). I'm currently working on a project of swapping a 99 engine tranny and transfer case into a 91 cherokee. I'm doing a interior and dash swap as well though. That way I don't have to worry about the wiring harness. It requires a little welding and replacing some brackets. You would definetly need a donor Jeep. I'm going to do a step by step thread on the build.

Also the 2000 model uses the 1999 version of the Grand Cherokee 4.0 thus the coil packs and such. It runs quieter and has lower emissions.

coastie124 said:

Well the first thing you should know is that the wiring changed in 1997 to a multiplex wiring system. The harness will not match up with your dash. And if you don't have the harness then you have another problem. First things first get an engine wiring harness. Then I'm sure you could find a way to tie it into your dash(maybe :dunno: ). I'm currently working on a project of swapping a 99 engine tranny and transfer case into a 91 cherokee. I'm doing a interior and dash swap as well though. That way I don't have to worry about the wiring harness. It requires a little welding and replacing some brackets. You would definetly need a donor Jeep. I'm going to do a step by step thread on the build.

Also the 2000 model uses the 1999 version of the Grand Cherokee 4.0 thus the coil packs and such. It runs quieter and has lower emissions.

Click to expand...

Ahhh I'm glad to know you're working on the same thing I am with the whole engine, tranny, dash, etc. I may contact you backchannel if I have questions on the dash at all.

Sorry i'm hijacking your thread but here is my setup. One 1991 Cherokee Laredo. Black, 6.5" rusty's lift kit. Dana 44 rear with a powertrax no-slip locker. Front Dana 30. Not sure of the gearing as of yet. Currently has no motor in it. Cost me $560.

The Donor is a 99 Cherokee Sport that was rolled onto the roof. It's got 88k on it. The transfer case (np231) was replaced 5k ago. It looks brand spankin new. Cost me $650. Parts I'm canabilizing:
Engine
Tranny Auto
Transfer Case
Front Dana 30 without the vaccum disconnect
Dash
Interior
Steering column (it's got tilt :yelclap: )
All engine compartment goodies i.e. AC components, resevoirs, etc. . .

Then everything else is getting parted out to offset the cost of the Jeep.

Got a set of 33" BFG mud terrains that are in great shape. $150

I'm hoping to, after I part everything out, have a rig built for under $1000.

I'm looking at doing something simular. I have a 88 Xj and want to put the HO engine from a 92 in it. Would I be better off using the 92 wiring harness and computer? Are the auto tranies the same here? I would like to use the fuel injection from the 92 also, what is different there?

Yeah your going to have to swap your wiring harness over. I'm not sure how the dash harness will mate up. As for the Tranny i'm not sure. I would think it would be the same.

Ok well i looked at it closer today and as far as the motor is concerned all i have to do is swap sensors from the old motor and then i have no issues. I'm also sure the transfer case is the same and no problems there, now the only thing i dont know is how the aw4 tranny changed over the years. Does anyone know if the trans computer has changed? Oh and yes the trans bell housing did change in 99 but that does not affect me because im using the whole drivetrain. And as far as wireing it into the dash the speed sensor is in the transfer case and i can swap the sensor from my old one. Thanks for the help so far everyone.

jeep1947 said:

Oh and yes the trans bell housing did change in 99

Click to expand...

Out of curiosity -
How did the bell housing change?
Eddie

jeep1947 said:

Ok I have a 93' cherokee with the 4.0, the motor, trany and transfer case all went on me over the course of a week. So i found a new compleate motor, trans, and transfer case out of a 2000 jeep with 40k on it and i got a great deal the whole thing for $350. But the problem is that the 2000 motor is not the exact same, for one it has the coil pack instead of a distributor. Does the cam still have the distributor gear on it because if so i should just be able to use my old distributor. I am also wondering if any of the wireing changed significantly. Now i am experienced and im a mechanic, i just want to have some idea of what im in for when i start this on the weekend. Some one out there has had to of done this before, but searching found nothing. Thanks

Click to expand...

I'm still curious how all three items "went" on you in one week? i.e. if the motor was out, how would you be able to drive it so the tranny would go out? If the tranny was out, how'd the TC go out? etc. etc...

If I sound like a dick it's not on purpose - I'm just really curious how this happened?

pokeyxj said:

I'm looking at doing something simular. I have a 88 Xj and want to put the HO engine from a 92 in it. Would I be better off using the 92 wiring harness and computer? Are the auto tranies the same here? I would like to use the fuel injection from the 92 also, what is different there?

Click to expand...

Here is how to put a 91-95 OBD1 4.0L into a 87-90 Renix XJ:
http://www.terrainstompers.com/forum/viewtopic.php?p=27
I assume a newer (OBD2) 4.0L would only be slightly more complicated.

The newer injectors in the 92 4.0L fuel rail dropped into the Renix system will flow more fuel, leading to a little more power but less mpg.

In response to the 4.0L with coil packs in an older XJ, I believe you would have to use the year of the XJ you're putting it in's distributor for it to work correctly. I cannot see a reason to swap the whole harness/dash over unless you have too much time on your hands or are a complete masochist.

I swapping both because I have it and it'll look sweet. Lots of work though. Plus I don't have to worry about gremlins in my wiring. I have a donor 99 that was rolled. I'm replacing the engine to the transfer case, and the front axle and the interior. I'm also looking at replacing the front clip and the rear hatch and lights. Then I'll pretty much have a 99 xj for next to nothing. Also I'm not sure of the condition of the 91's wiring harness as I purchased it without an engine.

Chili Palmer said:

I'm still curious how all three items "went" on you in one week? i.e. if the motor was out, how would you be able to drive it so the tranny would go out? If the tranny was out, how'd the TC go out? etc. etc...

If I sound like a dick it's not on purpose - I'm just really curious how this happened?

Click to expand...

Well I had a burnt exhaust valve then I started to get a light rod knock under load. Then a couple of days later the trans started clicking when trying to go into reverse, and only got worse to the point of no reverse in one day. The day after that I was driving to work and hit a big pot hole (I live 6 miles from pavement) and blew out the bearing im assuming for the front output in the T-case which ended up destroying the front output shaft.

Now for an update I actually started pulling the motor tonight and did some planning. Every sensor on the motor can be swapped except for the knock sensor on the back of the block, on the 2000 motor it is on the right side of the block and there is no hole in the newer block for the old sensor. I think i might measure and drill a hole in the same place on the newer block. Oh im thinking it will be easiest to drop the whole motor-tranny-tcase out the bottom, take out cross member and front axle. Has anyone ever tried this? It looks like everything will clear and that would make it nice and easy.Thanks for the input guys I will post some pics tomorrow.

They haven't had knock sensors since 1990, not sure what sensor your talking about though. I think you can put that motor in will all your sensors and dizzy and be just fine, benefit from the newer style intake and cam as well.

pokeyxj said:

I'm looking at doing something simular. I have a 88 Xj and want to put the HO engine from a 92 in it. Would I be better off using the 92 wiring harness and computer? Are the auto tranies the same here? I would like to use the fuel injection from the 92 also, what is different there?

Click to expand...

The trannies should swap. The same TCU should work on either as well, although if you use the 92 engine computer, you'll probably want to use the 92 TCU. The 92 TCU normally gets its TPS signal directly from the engine computer instead of the dual output TPS that the Renix had.

coastie124 said:

I swapping both because I have it and it'll look sweet. Lots of work though. Plus I don't have to worry about gremlins in my wiring. I have a donor 99 that was rolled. I'm replacing the engine to the transfer case, and the front axle and the interior. I'm also looking at replacing the front clip and the rear hatch and lights. Then I'll pretty much have a 99 xj for next to nothing. Also I'm not sure of the condition of the 91's wiring harness as I purchased it without an engine.

Click to expand...

You wont be able to swap the hatch at all. Completely different hinge attachment and the early body structure cannot handle the weight of a steel tailgate instead of the fireglass one either.
You could do some cutting and glassing to make the taillights fit the old tailgate maybe as they are taller and narrower. Maybe glass over the licence plate recess and add the later model brow over it to bring it up to date?

pokeyxj said:

I'm looking at doing something simular. I have a 88 Xj and want to put the HO engine from a 92 in it. Would I be better off using the 92 wiring harness and computer? Are the auto tranies the same here? I would like to use the fuel injection from the 92 also, what is different there?

Click to expand...

The autos are not the same between those years as the 91+ has 23 spline output shaft and the early has 21. Would need to swap in the transfercase as well from the 92.