Jeep Xj Engine

RockMonkey

Suddenly Enthusiastic
:eek: Wrong. The computer fuel injection systems in the 90 and 92 are completely different. The head is also different on the 92.

No, it's not an "easy" swap, but it's doable, but you're going to be changing out fuel injection/sensors/throttle body etc

Would it be easier to just swap the ECM and wiring harness along with the engine into the 90?
 

DaveB

Long Jeep Fan
Location
Holladay, Utah
The ECM on a 90 is mounted inside the jeep and on a 92 the ECM is in the engine compartment so there would be alot of wiring changes. I would think that swapping the 92 long block in while keeping the wiring, intake, and exhaust from the 90 should work just fine.
 

chans

Registered User
Location
Sandy
The ECM on a 90 is mounted inside the jeep and on a 92 the ECM is in the engine compartment so there would be alot of wiring changes. I would think that swapping the 92 long block in while keeping the wiring, intake, and exhaust from the 90 should work just fine.

This is what we are doing. We are swaping a XJ engine into a YJ and just stripping the XJ engine down to a long block and putting on all the YJ stuff. They may not have the same holes for all the accessories but they can be mounted elsewhere.
 
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This is what we are doing. We are swaping a XJ engine into a YJ and just stripping the XJ engine down to a long block and putting on all the YJ stuff. They may not have the same holes for all the accessories but they can be mounted elsewhere.

This sounds like an option I might try for. I think it might be a better motor then the carb one I have in my 88yj.
 

chans

Registered User
Location
Sandy
The oil sending unit connection has to be spliced together since the connectors are different and the coil from the YJ can mount to the bracket towards the front of the engine and there are two sensors on the side of the XJ block that are not needed to connect to the YJ wiring. You have to swap over everything from the front including the thermostat housing since the YJ has the temp sender in that and the XJ fan is offset to the side and not in front of the water pump but we left the water pump. Should have it dropped in in a few weeks and running.
 
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DaveB

Long Jeep Fan
Location
Holladay, Utah
Watch out for the direction of rotation on the water pump some of the serpentine belt setups turn the pump in the opposite direction and I don't remember if the xj is one of the oddballs. On my CJ when I put in the 4.0 I used the front brackets and accesories from a TJ which had the fan in the center rather than offset like the xj.
 
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