4.2 is carbed. No XJs had these.

4.0 Renix has a funky 3-screw air hose on the throttle body

4.0 Chrysler "HO" has the air hose attached to the throttle body with a clamp.

 

Or get the engine number off the block and post it up.

 

Old thread for sure but needs clarification.

HO only had 8 more horsepower than the 89 and 90 Renix. 89 and 90 had more power than 87 and 88 solely because of the ECU maps. Throw an 89 or 90 ECU in your Jeep that's compatible with your auto or standard trans and enjoy some more power. Same cam in early HOs as Renix. Ho had no more torque, but had the HP gain in higher RPMs due to a freer flowing exhaust manifold, different intake ports, and a 58mm throttle body versus a 52mm one on the Renix.

 

Should also post this:

XJ
Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange.

2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange.

XJ/ZJ blocks and 2000+ TJ/WJ blocks do not interchange without significant modifications. (1991 to 1995 YJ and 1997-1999 4.0L TJ Wrangler blocks will interchange in XJ/ZJ and visa-versa).

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.

　

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)

 

And this before the question gets asked:

Cruiser’s HO into Renix Swap

This swap is easier than some will lead you to believe, generally 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.

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

Any HO engine from an XJ or ZJ through 1999 can be used. 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 the HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head 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 the Renix gasket. Exhaust ports are identical.

You will need to use your Renix distributor as it is different than the HO because they use different fuel management systems. 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.

　

Revised 03/28/13

　

 

I felt that jab.....funky

 

Oh come on dude. The day you saw that you must've thought it looked like some kind of S&M heffalump Dr Seuss nose thing too. LOL

 

Ya know, now I see it in a whole nudder perspective!!

 

109MX06 is the number on the side...
It has all the same radiator and intake as the HO but i did know if they would just take the all that stuff and stick it on the 88 motor. I really don't know what can be crossed with what.

 

I decipher that date code to be September 6th, 1991.

If you want, I can use the 10 digit number embossed in big numbers on the drivers side of the engine block towards the front. Gotta crawl under to get it.

 

Okay so then i didn't get screwed over and it has the HO motor in it. sweet thanks! What means what in the code?

 

really enjoyed reading this post learned a lot. thanks to all,

 

http://www.justanswer.com/jeep/2p5bm...determine.html

 

1987-91 or 92 was renix non-HO 4.0.(177hp) 92/93-96 is HO 4.0 (190hp) I believe it was a matter of changing the intake a bit. Torque peak for around then was about 4000rpm I think. 1997-01 was the "Power Tech", basically a re-branded H.O.,(190hp) torque peak was 3000rpm or so. Again, not sure about the 91/92/93 years, when that initial change was. But I do believe the difference for the non-HO and HO was intake and injectors.

 

Bit late to the thread eh? Lol

1990 model year was the last Renault/Bendix "Renix" fuel system management and original intake design. For the 1991 model year Chrysler eliminated the EGR, redesigned the intake and head ports, and added their own OBD-I system.