Thoughts on replacing a CJ-7 258/4.2 L with a 4 L Jeep Cherokee

[84 Renegade]

Does anyone have any thoughts on replacing my old worn out i6 258cu with a Jeep Cherokees 4 L engine. I was going to just add on an EFI kit, but walked into a deal to get the Cherokee engine (vehicle rollover and being parted out)? Anything negative to doing this? Unknown costs? Sounds like a great deal to accomplish the same as the EFI kit, but cheaper.

[jagular7]

I'd check with Jeep specific forums (jeepsunlimited, jeepforum, pirate4x4 and the like). The local club may have some info, but obviously, others have done it out there as well. Painless Wiring (and others) may even have a wire harness just for the swap.
Things to consider: CPU, auto vs manual trans (computer for auto and CPUs may be different), fuel pump/pressure, fuel lines, intank pump vs outside mount fuel pump, wire harness. Then there is the motor mounts, trans bellhousing to bolt to block, radiator hose locations.

Then another thing to consider and its been done a lot, mixing the 258 and 4.0l hardware to get a stroked engine (I'm thinking its the 4l block, 258 crank, rods and pistons, 4l head/intake efi.

[rustinh1]

It's not a bad swap at all. Fairly straightforward as long as the donor is OBDI. If it's OBDII, it's still doable, but a bit more difficult.

[JEEPINKC]

It's not bad at all. I put one out of a 96 Grand into a 83 CJ-7 a few years ago. If you can get everything from the donor vehicle it will help quite a bit.
Here are a few things that I can remember having to but separate off the top of my head.

Flywheel for a manual trans with sensor ring(donor was an auto)
Inline frame mounted fuel pump
WJ(?) fuel filter/regulator assembly
PCM for a manual trans(again auto donor)
Plan on lots of little things like connectors, fittings and misc hardware items.

I was able to make my own bracket for the CPS sensor after dilling the CJ bellhousing
I found factory wiring diagrams and basically stripped the donor harness down to the bare minimum and used the donor fuse block as well.

I still have a bunch of my notes and part # used if you get to that point I would be more than willing to share.

There is a ton of good info on CJOFFROAD.com also.

[Guest]

I replaced the 4.2 in my 87 YJ with a 4.0 from an 89 XJ. If you have any questions feel free to PM me.

[84 Renegade]

Thanks for the information

All, I really appreciate all the input. Thanks