How do you tell the different between a Renix and a HO
My uncle who built the jeep (its an 89) told me he replaced the orig motor and
put an HO in it, But ive had people tell me it was a renix. how do i find out for sure? what do i look for?

 

I tried getting comparable views for ya...

Heres a RENIX:


Heres an H.O.

 

It's going to be a renix most likely. The ho 4.0 (92+) is a pretty in depth swap. Damn near a nightmare of swapping harnesses. The two are very distinguishable. Compare the pics xj put up and it'll answer your question. It can be done but it's a LOT of work.

 

87-90 has the Renix engine control system. 91 and up are the Chrysler H.O. system. The main difference is the head, intake manifold, throttle body, and several engine sensors. The basic engine block is the same throughout the 4.0 production and is interchangeable.

 

mine is a 94 motor in my 90 xj.
previous owner had it installed, so i'm not quite sure what was involved.
however, it has most of the renix parts swapped onto the new H.O. block.

but all in all, it's still the lower hp renix as the intake, harness and puter is still original to the 90.

so yes, it is possible.

 

i'm not 100% sure but i think you can tell by the cooling system. older ones didn't have radiator caps, i think...

 

Renix 87-90, HO 91+

 

well see thats just it. my uncle put a new radiator in it. one with a cap.

 

Yeah i know that. but my uncle ( before he passed ) told me he swaped the orig engin and put a HO in it.

 

How many bolts are used to hold the throttle body to the intake manifold? The Renix system only uses 3 and the H.O. uses 4. Your uncle may have only used the H.O. block and head, but used all the Renix intake and sensors, or he may have did a full swap including wiring, sensors, intake, and cooling system.

The port difference in the heads and intakes makes it a nondesirable interchange but it will work. A Renix head with H.O. intake, and vice versa, will run but does not flow well and performance and gas mileage will suffer.

 

take pic of the engine

 

holy clean engines!!!

 

i just took the long block out of my 91 ho and put it in my 88 and i just used all the stuff from the 88 cause the ho wirin about mad me pull my hair out. and another thing to look at is how the fuel lines hook on to the fuel rail died give away

 

the other thing that comes to mind, my 89 renix took a ph3985 oil filter, and my 90 (with a 94HO motor) takes a ph16. so does my 97 and 99 tj 4.0L.

check yours and let us know which filter you have.