getblown5.9

I am getting ready to start replacing my 96 XJ motor with one out of a 99 XJ donor truck. I plan on keeping all the 96 wiring/ECM stuff, just hoping to use the motor and replace all sensors etc on it with the parts from the 96.

sidenote- 96 motor is coming out due to an issue with the cam wearing off distributor gears.

getblown5.9

noticed the intake manifolds are shaped different. the 96 is kind of squared, and the 99 is all rounded to the throttle body...

any of this make a difference?

Mike1998XJ

I just replaced the 1998 with a 1999 motor out of a donor jeep. As long as you have everything it should be fine. Instead of moving the sensors out of the 1998 into the 1999, I just used the wire harness's off the 1999 that goes into the front 2 ports of the computer. (In car position).
I then used the 1999 computer.
The starter, ac and fuel injectors have different plugs on the end so just use the 1999 parts and it will hook right up.
I ran mine on the 1998 computer also to see if it would run and it ran fine. I currently have the 1999 computer in there.
That's my experience. My 1998 had the same (more square) manifold as yours, although your jeep is older.
Take a look at what I said and see if you can do it that way.
Mike

getblown5.9

well the donor is a running 99 with harness and ECM which is not a problem to convert. I know that the interiors changed from 96 to 97, but i didnt know if there were any other major wiring/control changes. my main issue is I want all the dash gauges etc to work still as this is a daily driver also.

diskman

Keep the 1999 intake manifold on the engine. It's good for a few more ponies under the hood due to the larger volume. You will need the power steering pump and bracket from a donor '99 to keep the manifold. You original sensors will just screw or attach to the '99 engine just fine. I have heard that there is an extra hole in the intake manifold that you will need to plug up though. Otherwise it's pretty straightforward to swap around. Same engines. Different sensors but they can be swapped.

xjbones

7

Mike1998XJ

He's putting in a 99 not an 01. 99 still had distributor...

xjbones

5

Mike1998XJ

See this engine. It is a 1999.5 that I dropped into my 1998. I did not have to change any sensors. I used the starter, manifold, AC unit, exhaust manifold, and the two front wireing harnesses that plug into the front 2 ports in the computer and the computer out of the 1999 donor.

The Donor was a Cherokee Sport and the Red Jeep is a Cherokee Classic with the overhead mpg, Compass and temp gauge.
Everything works in mine.
I researched this quite a bit before I did it. You cannot hurt your current computer if it doesn't work. If you have things that don't work just swap in the 1999 computer.
This way you don't risk breaking any sensors and it will take you half the time because all the plugs will screw or plug right in.
Like I said I ran the 1998 on both computers to see what it would do and it ran fine with each.
Mike

getblown5.9

thanks for the tips guys, hoping to dive in and get this done soon. would like to do some re-wiring of my stereo accessories and clean up the engine bay while im at it.

i confirmed the cam gear is damaged today, pulled the dist out, the gear is all chewed up and looked down in the motor, the cam gear has the teeth worn pretty bad.

as cheap as i got the donor engine i will be able to swap them for less than pulling the motor to drop in a new cam.

xjbones

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Mike1998XJ

He doesn't have to swap the whole harness just the front two that go to the motor. I said to use the 1999 manifold look at the picture I posted can't you see! Everything on it is off the 1999.
He said he wondered if the computer would run his stuff, he was worried it wouldn't. Now he knows.
Do it the hard way like you did so he takes twice as long. Congrats to you too you overly complicated a simple job! The donor jeep is the key!

Mike

xjbones

d

Mike1998XJ

Yea, I just looked at your posts you are truely an opinionated genius! Why don't you chill out Bro. If you can't identify a 99 motor and components with a clear picture maybe your advice is about that accurate also.
Mike

xjbones

5