Can I swap an 85 v-6 for a 90 I-6?

Just as I got my lift done the V 6 died. its a standard and carb. I have access to an I 6 and the trans stuff i need to keep it a standard. I need to know what I have to do for the computer and the harness. some help or advice would be greatly appreciated.

Sell your first born to a salvage yard.

Locating a donor vehicle would be a cheap solution - the engine management system must be pulled completely and relocated under your hood. At this point you can at least choose to use '92 and up components, avoiding the scarcer and more challenging '90 Renix setup. Either way, you will need the complete wiring harness under hood and at least the balance of the underdash setup, so access to a Factory Service Manual will be almost mandatory to know what's up. Then, the various sensors, many already attached to a donor engine, are next, an appropriate radiator and hoses, ignition system, motor mounts, power steering hoses, A/C mount and hoses to fit the new motor, fuel injection pump and lines for the tank, air intake system, and electric fan setup. If any of the compatible items from your present setup will work, great, just don't assume anything will be the same. Do as much as possible while the engine is out, starting from the fuel pump and work forward systematically, take pictures with a digital camera, and keep in touch so we can keep giving pointers.

Most of us haven't done it, including me, but it can be done. You need to ask yourself if maybe swapping your mods to a runner wouldn't be easier?

Don't forget that your current radiator will most certainly be insufficient to cool the 4.0L
The killer swap for the 2.8L is a Chevy 3.1 or 3.4L v6. The block swaps right in with only a couple small mods. Check out the links on this page for more info:

http://home.earthlink.net/~jeepcherokee1/Project XJ/Project XJ.htm
Specifically this one:
http://www.off-road.com/jeep/cherokee/xjtech/engine/28-34swap.html

Jeep on!
--Pete

I may be mistaken, but didn't they change the firewall to fit the I6 in '87?

Search can be your friend:

http://www.naxja.org/forum/showthread.php?t=21963

sjx40250 said:

I may be mistaken, but didn't they change the firewall to fit the I6 in '87?

Click to expand...

i am pretty sure they did but the swap can be done. you just have to adjust everything forward a little.
another idea for a good swap is the 4.3 v6 from a blazer but you will need the transmission and harness for it also. they don't have an adapter for that motor to a jeep tranny if i recall right. but it can be done a buddy and i are just finishing one in his TJ because his 4 banger wasn't doing it for him.

If you're a sadist go for it :wierd: , otherwise a 3.4 out of a firebird or camaro will drop right in with only a very few things to change and they'll all be things you already have on the 2.8. You can either reuse the 2.8 intake and put a weber on it or if you're more ambitious get a wiring harness made and use the 3.4's fuel injection. The 2.8 flywheel will need to be 0 balanced, and you'll need an electric fuel pump... other than that all the rest is just moving the alternator and stuff from the 2.8 onto the 3.4.
IMHO you're better off swapping the lift over to another XJ than trying to stuff the 4.0 in a 84-86 if you'd rather not do the 3.4 swap.
Mike B.

If it helps any th 4.3 chevy motor mounts ar the same as a 350 any trans that will bolt to a 350 will bolt to a 4.3. the 4.3 is a hell of an engine i have one sitting in my garage to rebuild and bor out .060 over hehe. dump the stock tbi an go with a carb system.


just my e cents

The 3.4L is the same 60-degree block as the 2.8L so it is a bolt-in swap. The 4.3L is basically a shortened version of the Chevy small-block V8. It's a 90-degree configuration, which makes a wider engine that's a very tight fit in an XJ engine compartment. Plus needing all the same adapters that would be needed to swap in a SBC V8. I don't see the point.

Do the swap we did it with a 88 4.0 L and the auto and trans, to an 86 that had a 2.8 five speed. just take the 2.8 out and get rid of the engine harness. find a donor jeep take the motor the motor harness and swap it in. you will need the donor jeeps motor frame mounts. this bolt right in to the 2.8 motor compartment. Take your front clip off your headlight grill assemble. then take the measurments for the radiator cut what you dont need out of the jeep your keeping. fab in a lower radiator and bolt in the radaitor and the top bracket from the donor jeep. you will need to use hood pins or if your a good fab man, swap the hood laches from the donor jeep. the motor mounts are an easy fix, use stock one they bolt right in. or I can make you a set that have a lifetime warrent, on the welds. if you have any more questions just let me know i will be glad to help.