Engine swap question

[jwdvy4]

I am planning on getting a 91 4.0 HO motor to replace my blown renix injected 4.0. My question is will the throttle body work with the newer intake of the 91 or will I have to find one to put on it? Also I am assuming that my old alternator and power steering pump will be a direct swap?

[Pete M]

what part of the renix engine blew up?

[Eagle]

The two throttle bodies are completely different. I believe a few people have been able to adapt, but your existing throttle body will not directly bolt to the newer intake manifold. And the old intake manifold will not bolt to the new head without modifications.

[jwdvy4]

It seized up on me. It had 313,000 miles on it.

[Pete M]

the block itself should bolt to the head with minimal fuss. :thumbsup: that's what I've read at least. the pilot bushing/bearing may be an issue but I think someone found a cure for that. I think. :dunno:

[juan]

I just swapped a 94 HO 4.0 engine into my renix 88MJ. I ditched everything exept the engine block - all renix related components will bolt right in.

[75sv1]

There are a few problems to deal with when swapping in an HO, in place of the Renix. First is the TB, the next is the fuel lines (fuel rail or fuel log). The bolt pattern is different from the Renix to the HO. I don't of anyone making an adapter plate presently. The other solution is to use the HO TB and adapt the electronics of the Renix to it. I think HESCO sells a kit for that. I think its $100.00 though. I looked into d oing that at one time. The mod didn't look difficult. You might to a web search.

The bolt tabs for the Renix and HO fuel rails are different. So are the locations of the fuel lines. The HOs are both at the front. The Renix has one at the front and one at the rear. My plan was to use an HO fuel rail and use fuel line to connect the metal lines from a '95 to the metal fuel lines at the frame rail in the MJ. Not as hard as it sounds.

Of course you have to swap on your electronics such as distributor. Basically, you can swap on any year head, onto any year block. The latter blocks from '96 up have locator dowel holes. That would affect you with the '92 block. So, you could swap on your Renix head. I swapped on a '95 head onto an '03 block. The engine mounting bracket holes should be the same up to at least '00. I had problems with my '03, but adapted it. A spacer and cut and welded an ear off one sides bracket. If you are close to IN, I have a '95 block that could be salvaged, for free.

As far as the pilot bearing bushing, I would check with Advanced Adapters.

Tom

[jwdvy4]

No problems any more. I talked the guy into giving me everything for the motor. Which includes a complete motor, accessories, the ECM, and wiring harness. I know it was from a cherokee with an automatic tranny. but i have an AX-15 in my comanche. I don't think there will be any problems with that but I could be wrong.

[75sv1]

The auto wiring will work. There is a writeup on Jeep.com, I think on this. It a lot more work in my opinion though.

Tom