Tuska_xj89

Hello there,

I have an 89 Xj that threw a rod so now im swapping the motor and decided id clean up the harnesses while i was at it ive decided i want to Microsquirt a HO 4.0l. I was wondering if anyone had some helpful hints or tips. The biggest issues im seeing at the moment will be controlling the AW4 and Tuning. I was wondering if anyone had a tune for a stock HO 4.0

TRCM

Heard of (actually had at 1 time) a MegaSquirt....never heard of microsquirt....is that it's younger brother ??

Tuska_xj89

Its just a smaller V3 Megasquirt (from what i need and can tell)

andrewmp6

Sounds like more work then its worth to me,Unless your trying to build some high powered monster or a race car maybe a daily driver no.

cruiser54

Why reinvent the wheel?

It's easy to put an HO in where a REnix was.

Here's how:

This swap is easier than some will lead you to believe. And generally Pooh-poohed by those who have never done it. Those of us who have done it, like myself, will share with you the things that need to be done for a successful swap. Just think of it as swapping in a long block.

XJ Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange.
2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange.
YJ and 1997-1999 4.0L TJ blocks will interchange in XJ/ZJ
XJ/ZJ blocks, and the 2000+ TJ/WJ blocks do not interchange without significant modifications.
TJ/WJ 4.0L Engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand and 2000 TJ Wrangler. These blocks are not interchangeable with XJ/ZJ engine blocks. The reason is motor mount bolt holes and belt driven accessory mounting bolt holes are in different locations, or not present at all, TJ/WJ vs. XJ/ZJ.

Now that we know which engines we can use, let’s get down to business.

The HO and Renix have some differences but none that can’t be overcome very easily.

One running change was that the rear of the head was no longer drilled and tapped for the temperature gauge sender beginning in the 96 model year. The sender can be relocated to the threaded hole in the thermostat housing taken from an HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head at the rear for the sender.

You will be using the intake and exhaust manifolds from your Renix, along with all your sensors and wiring. Since the intake ports of the HO are slightly different, you use a new Renix gasket. Exhaust ports are identical.

An alternative on exhaust manifolds:

As far as exhaust, you can use the Renix exhaust manifold and be fine.
If you want to use the HO exhaust manifold, you must go with an HO headpipe and screw your O2 sensor into that headpipe. Standard Renix harness is plenty long to do so.
A bung can be welded into the HO manifold to accept the EGR tube.

You will need to use your Renix distributor as it is different than the HO design. See Tips #12 – Setting Your 4.0 to #1 TDC and #13 – Distributor Indexing to be sure you get the distributor installed correctly.

The flywheel or flexplate from the Renix must be used so your CPS gets the correct signals. The valve cover from the Renix allows you to keep your CCV system intact and requires no modifications.

The HO block will have a plug in the coolant galley on the driver’s side of the block, closest to the front, which needs to be removed so your Coolant Temp Sensor can be installed in it’s place just as it is on the Renix. It requires a 5/16” square drive or a modified 3/8” drive that has been ground down to fit. Do this before installing the engine.

As for the knock sensor, which is located just above the oil pan on the driver’s side of the engine about mid way, all the blocks I’ve seen are threaded for it. If not, I’ve heard they may be drilled but not tapped. Tap the hole if that’s the case.



XJ: “Regular” (not Grand) Cherokees ’84-’01
ZJ: Grand Cherokee ’93-’98 (Gen1)
WJ: Grand Cherokee ’99-’04 (Gen2)
YJ: Wrangler ’87-’95 (Gen1)
TJ: Wrangler ’97-’06 (Gen2)

Tuska_xj89

I know that i can run a HO with the Renix. The main reason i wanna swap it is i bought this jeep little over 6 months ago with the plan to do a rebuild, sliders, lockers, at least clean up my spaghetti wiring harness i have. The micro squirt really isn't that bad its just connecting wires Im sorry i cant resize these pictures at the moment. Pictures of my front grille snf rad off, along with my valve cover.

Removed the front along with the radiator.


Hole in the side of cylinder 3


Latest update ready to pull just need the lift.


Sorry for the late response its been a very long week.

andrewmp6

If im going that far id think about a stroker kit or stroker long block and a better cam.

s346k

if you're going to spend that kind of money just do a lsx swap.

Tuska_xj89

I hate that thats everyones goto ....... dont get me wrong its a good motor but everyone and their mother swaps a ls. Im thinking SBC or a stroker straight 6 but i just wanna get it running so i may just make it a renix again for the moment.

s346k

there is a reason for it. you can't touch the power/$ along with with mileage, tuning ability, inherent capability etc. the 4.0s are good motors and imho should be left stockish or swapped for something else. anything in between is a waste.