4.0 I6 Swap

Ryn109 · Mar 9, 2010

My Yj's motor/tranny are on their last leg (engine noise and little oil pressure/ lost 3rd and losing 2nd). Putting in a another 4.0 I6 and ax15 this weekend.
There any common mistakes people make while doing this? I have a repair manual but looking for advice from peoples own experiences. My first time doing an engine swap so I'm trying to be as prepared as possible. Searched for Old posts but came up with nothing. Any input will help thanks.

NotSoPC · Mar 9, 2010

Put tags on all wires and plugs then match the tags up on the new motor. After the old motor is out set it next to the new one and move the tags over. this makes it way easy to get the wires and plugs in the right spots.

Flat-Bed_3rd_Gen · Mar 9, 2010

make sure you have the right motor, i.e. proper crank sensor location and style so that it will bolt in

zukkev · Mar 9, 2010

Flat-Bed_3rd_Gen said:
make sure you have the right motor, i.e. proper crank sensor location and style so that it will bolt in

X2 on this....What yr is the rig, and what yr is the replacement motor?

Ryn109 · Mar 9, 2010

zukkev said:
X2 on this....What yr is the rig, and what yr is the replacement motor?

Mines a 92 yj motor is out of a 97 tj i believe.

chance · Mar 9, 2010

You should be good as long as your old motor is the 4.0 and the ax15 and the 4cyl and the ax5, I have the shitty set up with the 2.5 and the ax5 and I need to do the swap. Good luck and take lots of pic because I will be doing the same thing soon.

zukkev · Mar 9, 2010

chance said:
You should be good as long as your old motor is the 4.0 and the ax15 and the 4cyl and the ax5, I have the shitty set up with the 2.5 and the ax5 and I need to do the swap. Good luck and take lots of pic because I will be doing the same thing soon.

He's swapping 4.0 for 4.0...just a different yr is all....:;

BeatCJ · Mar 9, 2010

zukkev said:
He's swapping 4.0 for 4.0...just a different yr is all....:;

Well, maybe. I'm pretty sure '97 is OBDII. I know '92 is OBDI. I believe the block and head can interchange, but the OBDII sensors and computer are just a bit more complex. It's not "just" plug and play, but not really that different than some model year changes in earlier engines.

If it's not having access issues, there is a great forum on CJOffroad.com. I can't get to it right now though, to post a link.

PHILLBILLY1 · Mar 9, 2010

BeatCJ said:
Well, maybe. I'm pretty sure '97 is OBDII. I know '92 is OBDI. I believe the block and head can interchange, but the OBDII sensors and computer are just a bit more complex. It's not "just" plug and play, but not really that different than some model year changes in earlier engines.

If it's not having access issues, there is a great forum on CJOffroad.com. I can't get to it right now though, to post a link.

x2 Wiring harnesses are different. PM POS97TJ. He has been swapping harnesses around for a while in his new TJ. It seems like a bitch to get it right.

zukkev · Mar 9, 2010

BeatCJ said:
Well, maybe. I'm pretty sure '97 is OBDII. I know '92 is OBDI. I believe the block and head can interchange, but the OBDII sensors and computer are just a bit more complex. It's not "just" plug and play, but not really that different than some model year changes in earlier engines.

If it's not having access issues, there is a great forum on CJOffroad.com. I can't get to it right now though, to post a link.

Yes, the block/head IS interchangeable, but you have to use all the OBD I components from the 92 engine (intake/exh/dizzy/ sensors/wiring/etc....).

Ryn109 · Mar 9, 2010

zukkev said:
Yes, the block/head IS interchangeable, but you have to use all the OBD I components from the 92 engine (intake/exh/dizzy/ sensors/wiring/etc....).

The wiring harness on the 97 is cut. Would splicing them onto the old wires work? Or should i just use injectors and wires from my old motor? ODBI components interchangable from my 92 to 97? Whats best route to go? Thanks for all the info so far
:awesomework:

Ryn109 · Mar 10, 2010

chance said:
You should be good as long as your old motor is the 4.0 and the ax15 and the 4cyl and the ax5, I have the shitty set up with the 2.5 and the ax5 and I need to do the swap. Good luck and take lots of pic because I will be doing the same thing soon.

I'll take some pics and post them through the weekend.

BeatCJ · Mar 10, 2010

In MY opinion, if you have a complete running '92 engine, and just want to replace a tired block, I would use the '97 as a long block, and keep all the '92 accessories. Just use the harness that's already installed, same computer, etc. It's the simplest way, and there is no performance gain with the '97 electronics.