'98 4.0 into a '95 - Tips? Will it work?

A buddy is giving me a good price on a motor from a wrecked XJ. I have a '95 and his is a '98. Can I pull the motor and accessories and bolt it back in mine? Do I need the computer? Intake?

What else do I need besides the actual motor?

OBDI and OBDII.

You can use use the engine, but you need to use the computer/sensors of the 95.

If you want to "upgrade" to OBDII, you are going to need the donor computer, sensors, and probably the wiring harness too.

Ill stick with OBDI

Are all the connections the same for everything as far as the wiring harnesses go? I know the A/C hoses go into the A/C compressor different. Which is why Im asking.

I just want to make sure I can unplug my motor and plug this one back in. The donor jeep is a few hours away and i only want to make one trip lol.

If you're going to use the later motor I'm pretty sure you need to swap to OBD II... you'll need to move all the sensors and the computer from the donor vehicle into yours, which means you'll be moving to OBD II. No two ways about it.

Stick with OBDI, it's easier to work with. Take the complete 98 engine and drop it in. Use the throttle body and sensors from the 95. That way, everything will plug in like before.

The intakes should be the same. If not, bolt the 95 intake onto the 98 head.

kastein said:

If you're going to use the later motor I'm pretty sure you need to swap to OBD II... you'll need to move all the sensors and the computer from the donor vehicle into yours, which means you'll be moving to OBD II. No two ways about it.

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Why would you think this?

Apparently I'm an idiot. I shall keep my mouth shut when in engine threads and stick to things I understand better until I've learned more... sorry! :dunce:

kastein said:

Apparently I'm an idiot. I shall keep my mouth shut when in engine threads and stick to things I understand better until I've learned more... sorry! :dunce:

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No one thinks you are an idiot. If you had a reason for what you believe you should share it.

Keep the 95 sensors and injectors--you need those for the 95 computer to work. They will mostly go in the same place. The big exception is the temperature gauge/light sender at the back of the head, since there is no hole for it in the later heads, so you will need to drill and tap a hole in the flat spot on the thermostat housing and extend the wire up to the front under the loom. You also need to check the fuel rails, since the plumbing on those changed a few times over the years, and if they are different keep the 95 rail.

The other consideration is the power steering pump and tensioner bracket which was changed in 1996. The later setup has a better tensioner setup but you will need a pump for the 98 to use it. If your friend has the pump you are golden. Otherwise you can keep the dorky 95 tensioner setup and pump.

For everything else keep your accessories (A/C, alternator, etc) as there is no reason to change any of that.

joe_peters said:

No one thinks you are an idiot. If you had a reason for what you believe you should share it.

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For some reason I got it confused with renix vs non-renix (i.e. the knock sensor/CPS/other stuff would be different)

long story short, I don't have the Jeep engines "down" all that well... I must learn more.

kastein said:

For some reason I got it confused with renix vs non-renix (i.e. the knock sensor/CPS/other stuff would be different)

long story short, I don't have the Jeep engines "down" all that well... I must learn more.

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I think most of the 4.0s can be made to work with the different years, maybe 00+ being the most problematic with the distributorless setup.

Most of the issues can be worked out.