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Swapping 4.0 engines

smokeyyank

smokeyyank

NAXJA Forum User
Location
Littleton, Crawlarado
Quick question and I know it's been asked and answered but I need advice specific to my application and make sure my understanding is correct. I have a 93 XJ that I am going to scrape the body and move parts to a new 01 XJ I just bought. My biggest head scratcher is around the engine. My 93 has a rebuilt 4.0 that I want to swap to the 01, but I know it's different between the distributor, intake and head. My questions are, do I keep my distributor or do I need to swap it over to the coil on plug? If so do I cap the hole from the distributor? Secondly, I know a lot of guys swap the intake to the older motors so I'm assuming that should be somewhat straight forward. Anything I need to know? Past that any advice would be appreciated.

thanks
 
It would be easier to keep the 2001 computer and associated electronics than to retrofit all the other stuff to work with your 93 parts. That means you would need to swap in the 01 sensors and injectors and ignition etc. The 01 still has a cam sensor and oil pump so that will fill the hole. You would need to fabricate something for the coil packs.

You should keep the 2001 intake manifold and power steering setup, much improved

You will need to come up with something for the pre-cats and multiple O2 sensors, that stuff is going to be different from what's on your 93 engine. The exhaust ports on the 01 exhaust manifold won't line up fully with the 93 head, so you will need to figure out something there too.
 
Last edited:
Keep the 93 while you are rebuilding the engine in the 2001. Unless the 01 engine is in fine shape. Then run it and sell the 93 engine. Seems way easier to me.
 
Alright thanks for the replies! As for the exhaust I was planning on putting headers on and running an entire new exhaust. So if some fabbing is needed no worries there. The 01 runs for now but it's up there at 260k so I'd rather just swap over my current rebuild than sell and pay for another. Basically what I'm gathering is I can take my block minus manifolds and sensors and swap it over. Now i'm reading about Tayln's love for the coil system.
 
Watch out, the smog police will come get you.:anon:
 
done this type swap twice recently, basically you use the 93 longblock and like ehall said bolt ALL the sensors, ignition, intake etc from the 2001 on, super simple swap and just make a couple brackets to hold the coil rail down

now here is the biggest possible problem, the 2001 exhaust manifolds may not cover the ports on the 93 head, someone used to make a plate to make this combo work but I haven't seen one in a while, solution if you have federal emission is to use the 93 exhaust and buy a new front pipe, the 02 will bolt right in and work fine but if you have Cali emissions (4 02 sensors) you could have bungs installed in the 96 exhaust manifold so you can use all 4 02s,guessing you have 4 being an 01
 
Thanks for the info! Alright so for the exhaust manifold would I need to get headers for my 93 longblock and then have the rest of the exhaust fabed? Or do I need headers for the 2001? I'm assuming since the head will be from the 93 to get those headers and fab the rest of the exhaust. I'm in CO so no crazy emission laws but we still have our quirks! On another note I read Tayln's write up on the Viper coil and will go that route to eliminate the Coil on plug issue.
 
dan1977p said:
What is this coil on plug issue you speak of? Is it inherent in these because it was relatively new tech in 2000?
Click to expand...

In 00-01 Jeep got rid of the distributor system and replaced it with a coil on plug type system. It's not a horrible system but presents an issue with using the older head, as there are mounting and space issues. By switching to the Viper Coil you can again have the ability to diagnose misfires easier and it's just a little less headache overall for space. Look in Talyns sig for more info on it.
 
I'll look at it later since my experience with coil packs has been great since 2002 when VW recalled theirs and replaced them with better quality parts.
 
dan1977p said:
I'll look at it later since my experience with coil packs has been great since 2002 when VW recalled theirs and replaced them with better quality parts.
Click to expand...


Yeah they aren't a bad design just not the best especially with the earlier head.
 
So the other day I was looking around and came across the fact that on 01 XJ's California ruined it for everyone and we have pre cats. Since I'm wanting to keep my old head how will that work with a 01 manifold? I'm guessing I will need one of these http://jeepexhaustadapter.com/?
 
Talyn said:
Use a 00+ header. That plate still doesn't fix the wall that the exhaust hits on the way out.
Click to expand...

Well that is what I'm confused about. If I use just a 00+ header with no plate will it bolt up correctly? My thought is no but I may be wrong. I'd prefer to just run a header from a 93 and ditch the pre cats but I know that is a no-no.
 
The stock 2000-01 coil pack set-up is fine, there is no need to change it.

The simplest solution is to use an 0331 head on the donated engine block. If the head you have is cracked, buy a good used 0331 TUPY head from a TJ or WJ. Everything will bolt on with no adapters or modifications. Remove and re-use ( or replace with new ) as needed or required from your original engine: Intake/Exhaust manifolds, throttle body, flex plate/flywheel, cylinder head, water pump, distributor-less ignition or distributor assembly, OBD engine computer sensors, fan belt driven accessories, and/or mounting brackets.
 
smokeyyank said:
Well that is what I'm confused about. If I use just a 00+ header with no plate will it bolt up correctly?.
Click to expand...
Yes, an aftermarket header will bolt up and function just fine with the earlier heads.
 
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