• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

High output intake help


NAXJA Forum User
Gresham, Or
I got my hands on a 1995 high output 4 litre out of a grand cherokee and had some questions before I took out my tired 4 litre. If I use the intake and throttle body on it will it still pass DEQ without the EGR valve? I also found out that there is only one line coming into the fuel rail for the injectors.... how do I swap that stuff over? Should I just put my lod intake on the High Output engine??? Any help would be great
Yes you can install a HO engine in place of the old one. The question is how much to do want to spend in either time or money to upgrade. You can actually use your old intake manifold on the HO engine. Ports barely line up. You should also determine if you can hook up the knock sensor in the newer engine. You will need it for the Renix system. Using the old intake manifold will allow you to run the EGR.

I am sure if others read this post they will be more familiar. Did you try to do a search on the subject of engine swap or upgrade etc? Give it a try there are a number of threads that have addressed this issue.
I have done quite a bit of research on it and I keep on getting mixed answers, some say the intake lines up, some say it does not line up. I have not heard much about getting the h.o. fuel rail hooked up to a renix system because they are different, two lines on renix and one on the H.O.
I have a mechanic that has 17years with a DC shop on jeeps. He put an HO in his with the old manifold. It was close but he was able to get it to seal fine. The location pin on the head is in a different location. You can find out by getting a gasket for both years and see the difference. I have measurements somewhere. The ports on the HO are smaller and further up from the block surface.

One of the ways to test for manifold leaks is to spray brake cleaner around the gasket while the engine is running. If it falters you have a leak (vacuum).

I have a 90 and 92 (and by June a 97 GC). The difference between the fuel rails is both the mounting and the location of the return line. They both have them but on one (92) they are both in the front and on the 90 they are at opposite ends of the rail. Maybe it is the opposite configuration in years but both have return lines. The fuel regulator is also different but the reality is that they are interchangable between manifolds so pick the one you think will be easier to install. I believe the connections are the same. 91-95 are the same. 96 changed ECU systems.

The other issue you will face is the difference in the throttle bodies. There is info on how to adapt the more recent one on the Renix system. My preference would be to use the HO manifold and TB as they are improvements. I don't know how to address the DEQ issue about EGR but I think that topic was addressed as well. Maybe Eagle, Dyno or Martin can shead some light on this topic.
Thanks for all the help and information, I am going to try and do it in one weekend so any tips or advise is greatly appriciated. adapting the fuel lines and no egr are my main concerns with the H.O. manifold being used. TPS is easy to get around. thanks
So I should be able to use the renix fuel rail but the mounting holes might not line up correct? that would fix the fuel line issue. Maybe I can mount the EGR in the intake to. If I could find a way to do that that would be great! Has anyone done this
I have a 94 HO in my 89. I used the 89 intake and exhaust, The 89 fuel rail with the 94 injectors. I bought poth intake gaskets and used the one that looked best. Im sorry I dont remember what one. I have about 30,000 miles on it with no trouble. I thought it was too much trouble to use the newer intake. Just my .02
I think that way is going to be best as far as ease of instalation, just wanted to make sure I could do it that way. Did you swap the injectors just because of the higher flow rate, will that make a noticeable difference? Right now I have ford mustang 19lb SVO injectors I wounder which ones I should use. How was the performance of the engine?
I did it for the fact that they had less mileage on em. They do have a higher flow rate, But I havent noticed if they help or not. I added a tb spacer and k & n at the same time. It does run great.
Thanks for the help, I will be doing this swap this weekend so I hope it goes good. I will swap on the old intake and exhaust manifold to the H.O. engine. I need to weld up my Exhaust manifold and brace it a little bit so it does not crack again. It will be nice going from a tired 4.0 with 230,000 harsh miles, "lots of them off road" to a H.O. with intake, exhaust, injectors, and a throttle body spacer. Can't have my Jeep down on Monday because it is my daily driver! Josh
If you were going to use the HO intake, I believe you would also have to have the HO pcm and change your cam to work without the EGR. I may be wrong, but I think DC was able to eliminate the EGR by using a new cam with more valve overlap.
I'm know there are others here that WILL correct me if i'm wrong... :hang:
Thats good information and it makes sense, Using the renix intake will be much more hassle. I was soundering how the got around the EGR.
There is one more thing I forgot, the PILOT BUSHING! I have a 1989 AX-15 mating up to a 1995 4.0. What bushing do I need, no shops around here carry them and I need to compare them. Thanks
So if I am bolting up a 1995 engine to a 1989 AX-15 I will need a pilot bearing from advanced adapters. Isn't there somewhere else I can go that will have it, I just need the outside diameter of the 1995 crankshaft hole and the inside diameter of the old pilot bearing. Advance Adapters rips you off!!