Hi everyone, I apologize if this has been asked many times. I've searched and can't find my answer. I'm looking to do a complete swap of a 2000 Xj drive line into my 1999 Xj. I prefer not to do a partial swap. I have both complete xj's. For the coil pack 2000 to work in the 99, will the 99 wiring harness work on the 2000? I know I most likely will need the CPU from the 2000 because of the coil pack/distributor difference. Does anyone know if the dash wiring harness on the 99 will work on the 2000 computer? I am also aware of the head differences on these engines, the previous owner rebuilt and put the older, better head on already. My question is about fitment, and wiring difference. Thanks in advance!

 

Complete "Driveline Swap" I would not for sure the front differential is the weaker LPD30 and the 2000 also had 4 Cats on it instead of like the 2 on your 99. Exhaust is different also on the two.


Just my opinion but would be a step backwards, but each to his own I would find another 99 4.0 or rebuild what you now have and enjoy another 1/4 million miles..

 

i guess my statement was a little far....just engine, tranny and transfer case...the engine being the one i need, but was going to swap as a whole...diff's/axles stay. also trying not to spend money, having the complete system i am trying to work with what i have...may rebuild the 99 engine later

 

You know the 00 has the cracking head right ?Some have had the head replaced,How to tell which head it has http://www.jeepforum.com/forum/f11/t...1-head-977498/

 

Yes i'm aware, and this 2000 was rebuild less than 20k ago and has the tupy head on it...also for the other comment regarding exhaust, i have the entire donor jeep including exhaust if needed to use as well. My main question is regarding the wiring inside the jeep dash to the cpu and if it's the same. After looking at the haynes manual, it shows the exact same wiring diagram for 99 and 2000. I hope it's accurate. I'm trying to find out if anyone else has had experience with this as a piece of mind so i don't plug in the 2000 cpu and fry it do to a signal wiring change of some sort. I am a automated machine/robotics expert and deal with custom wiring of controllers all the time and know what can happen if for example you mix up a sourcing or sinking signal. you can fry i/o on the cpu if inot correct. Just trying to verify if possible before trying.

Thank you for any and all feedback, i really do appreciate you all taking the time.

 

I think another difference about the exhaust had to do with the LPD30 also but I may be wrong.

 

Just spit balling here, but what if he used the 2000 long block, since it has the tupy head, put the 99 exhaust manifold on it along with the distributor and coil? Then there would be no wiring issues. I think the long blocks are the same except for 2000 up has coil pack mounts.


I always see people going backwards with heads in 2000 up and the coil packs is the only issue that they run into. It should have the HO intake on the 99, so the exhaust/intake line up issue/clearance shouldn't happen.


Maybe???

 

That's because not many people would really want to do this.

The wiring harnesses are different between the two years because of the different emissions and the coil rail, and probably some other stuff they changed that would have to be rigged up to work. To use the 2000 computer to run the coil rail, you would also need the wiring harness. You would also have to transplant the emissions equipment, which would get complicated if you have the CA emissions with the three catalytic converters and the leak detection pump.

If you have the CA emissions and transplant the exhaust to keep the extra catalytic converters, you may also run into fitment issues. With the '99's HP Dana 30 installed, the front drive shaft will bang into the exhaust unless you're lifted. Also, I could be remembering incorrectly, but I think the transmission mount changed in 2000 to allow the exhaust to be routed differently.

I suppose you can swap the long block and run it off the '99's distributor, but I'm not sure how it would run with those tiny exhaust ports on the 0331 head. The 0331 head was designed for a waste spark ignition system. The ports may not be big enough to run on a motor that isn't burning away unspent fuel on the exhaust stroke.

Those two statements are mutually exclusive. The older head is the 0630 found in the '99s and earlier. The TUPY head is an 0331 head with a beefed up deck that didn't come into play until 2002 after the XJ went out of production. So which is it? If you have the 0630, just forget the coil rail, swap the long block and run it from the '99's distributor. If you have the 0331, come back and tell us how it runs once you get it done. Or better yet, start a build thread so we can see your progress.

 

So you know, I have the entire 2000 running complete as a unit. So I have 100% of the items including the exhaust transmission transfer case mounts and front differential if needed. I do plan to take the entire engine wiring harness with the motor and swap it into the 99 period my concern with the wiring is that the dash wiring harness is correct to accept the engine harness. All of these other points are valid and of a very useful information to me. But I do have all the hardware from the 2000 to make this work the only reason I'm not driving this 2000 is the front end damage that wrote it off and deploy the airbags.


Also for your info the Jeep does have a 5 inch lift on it

 

So in the end I installed the 2000 engine, tranny and transfer case with the wiring harness attached into the 99. Also took the CPU. Everything plugged in and worked perfectly with zero modifications or Problems. The coil packs and everything. Runs like a top, smooth as can be. It's an easy swap with no concerns

 

Cool. Please stick around so that you can answer questions the next time someone wants to do this.

 

How did the wiring harness from the 2000 hook up to the US/DS 02 sensors on the 99? Did you just use the 99 harness for the fuel rail and 02 sensors? I bought a 99 with a 2001 Grand Cherokee I6 swapped in running on a 99 harness and ECM, I have the whole 2001 harness from my last jeep with a working obd. 99 obd won't read due to rats. Currently I have the whole jeep stripped down and need to know which exhaust to order. Current exhaust is in need of replacement. If I can run on 99 exhaust with partial 2001 coil pack and ecm harness with no codes I would rather do that.

Questions 1: did you use 99 fuel rail harness section with 99 o2 sensors?
Question 2 : did that trip codes?

I'm trying to do a nice build, where everything works the way it should. I'm also going to try and install the GC AC compressor and run lines to XJ system. It's on the bottom right of the engine, and alternator is on the top left, the way "it should be."

- Lazzy

 

so would my 1999 engine work with my 2000 then because I need to swap it do to head cracking and causing coolant to get into the oil so it is something i can do as i can see good to know.