99TJ 4.0 motor to 2000 TJ sport

[RsDrifter]

First off hello to all I’ve used this as a search resource many times. First time posting as I’m kinda stumped here and looking for information and or advice.

I have a 2000 TJ sport that unfortunately shattered #1 piston. What I do have is a 4.0 out of a 99 Tj sport that I did a v8 conversion on sitting in the barn complete with motor harness and pcm. Of course the 99 is still distributor where as the 2000 has a coil pack. I was consider trying to drop it in as my 2000 is basically the work commuter nothing special. What I am finding is they say the 2000 pcm won’t communicate with the 99 motor and the 99 pcm won’t communicate with the dash in the 2000. Anybody know of a company that makes a piggy back to run the two pcms in tandem and or ever done this swap with success. Driving the 99 back and forth to work is getting a little rough as it’s not really set up to run the highway anymore. Thanks in advance.

 

[macleanflood]

What heads are on the 2000?

Have you pulled the engine and stripped it down?

Anything other than the piston? Connecting rod? Push rod?

How much metal went through the engine?

Just wondering if you can't tear it down, clean it up, maybe bucky ball the cylinders, replace the bearings, rod, piston etc and slap it back together.

-Mac

 

[RsDrifter]

What heads are on the 2000?

Have you pulled the engine and stripped it down?

Anything other than the piston? Connecting rod? Push rod?

How much metal went through the engine?

Just wondering if you can't tear it down, clean it up, maybe bucky ball the cylinders, replace the bearings, rod, piston etc and slap it back together.

-Mac

I haven’t looked at the head casting
Haven’t torn into it. Found it in a bore scope.
Quite a bit of metal in the oil to the point I would want to tear it all the way down. Center of the piston was completely gone
Honestly why I’m considering the 99 motor

 

[CharlesHS]

As you already probably have figured out; the 99 head does not have the provisions for the igniter rail, IIRC there is a difference in the accessory drive design on the front of the engine, I believe the OPDA from the ‘00 will insert into the distributor hole for the ‘99, but you are correct that the PCM from the ‘99 is not compatible with the’00.
You can swap the head from the ‘00 onto the ‘99 (IF it’s still usable), but the sensors may need to be swapped over due to differences in the connectors.

 

[RsDrifter]

As you already probably have figured out; the 99 head does not have the provisions for the igniter rail, IIRC there is a difference in the accessory drive design on the front of the engine, I believe the OPDA from the ‘00 will insert into the distributor hole for the ‘99, but you are correct that the PCM from the ‘99 is not compatible with the’00.
You can swap the head from the ‘00 onto the ‘99 (IF it’s still usable), but the sensors may need to be swapped over due to differences in the connectors.

Thank you for the insight I wasn’t aware the OPDA could replace the distributor on the 99 block i still have the 2000 motor if it’s possible to use the short block from the 99 along with the head and drive accessories from the 2000 motor I would look at just going that route even if to have the 2000 head reworked would be better to me than a full rebuild or losing communication with my dash as such