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Discussion Starter #1
Hello, I am wondering what would be a great year 4.0 engine to replace my 2006 4.0 with. I would like one that bolts right in, doesn't need that crazy computer, more mechanical then electronic controlled. One that puts out good power verses fuel usage. Any ideas? I'm just tired of dumping money into fixing this emissions junk every time I turn around. Thanks.
 

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It will be hard to have a mechanically controlled engine in a newer vehicle. The sensors all send their info to the PCM and it in turn controls the air/fuel, timing, spark etc. What problems have you had and what mods are you running?
 

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If you are going to do the complete swap of electronics, engine... why not a V8. The 5.2L from ZJs will get about the same mileage as the 4.0 and have much more power. The question is which tranny do you have? i do not know if the older 4.0 engines will bolt right to the 6 speed which only came out in 2005.
 

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Discussion Starter #4
The trans I have is the 42RLE, I don't live in an area that does emissions testing. I kind of want to stay with the straight six due to durablity and longevity. What the problem is I keep getting faulty codes from the computer when there is no issue at all. my engine is running solid at 91,000 young and still going. I just want to have a plan in place when the time comes for retirement. Any ideas?
 

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Discussion Starter #5
Sorry, didn't answer one question. One the engine there are no mods, bone stock, as is the rest of the drivetrain. All my mods are of the body, armor under and on the sides. Full roll cage, front stinger winch combo and rear stinger fold down arm. I have much more just can't think of them at hand.
 

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The 42RLE transmission is electronically controlled too...
 

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desertfox1 said:
The 42RLE transmission is electronically controlled too...
You mean electronically uncontrolable... Thank you the 10 pm show is compleatly different than the 1pm show. Make sure you take care of your waitreese. Good night omaha!!!
 

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Discussion Starter #8
So I would have to change out the transfer also so that I could run a non electronic controlled engine? What could I do if I didn't want to change that out?
 

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Well, you start by violating Federal Law. The Federal EPA regs about engine swaps say that only the same model year or later engine may be fitted to a smog-controlled vehicle. Practically this means that if you live in a state that does emission testing, you will fail the test and continue to fail. Therefore you will not be able to legally transfer title to anybody else in that state, since passing smog is required at sale. Thus you can only legally make this mod on an "offroad only" vehicle without plates, not driven on the road. And you own the vehicle until it gets scrapped.

Having said that, I once put 150,000 miles on a 4.0L HO engine in a 1992 XJ. I never had any internal engine failures, just an idler pulley and a couple of water pumps, which are bolt-on external parts. But it was still an OBD 1 engine with electronic ignition and electronic fuel injection, but with a high voltage only distributor, and timed off the flywheel sensor. But there are aftermarket carbureted manifolds and real distributors for that model year.

A 1992 with cam, free-flowing carbureted intake, and headers would put a smile on your face IMHO. But I don't know anything about the transmission compatibility, I had a 3-speed auto.
 

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Discussion Starter #10
Thanks, that gives me a start. I'm not planning on doing this soon. I want to keep the transfer case. The transmission, well I hear there isn't much that can be done to it to make it more durable.
 

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2000-2002, 4.0L

Do your research, and you'll see why.

:D
 

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Discussion Starter #13
Ok thanks I guess I should stay with the oldest year I can get. Anybody think there would be an issue with the 42RLE transmission bolting up to a 2000 4.0?
 

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toecutter1978 said:
Ok thanks I guess I should stay with the oldest year I can get. Anybody think there would be an issue with the 42RLE transmission bolting up to a 2000 4.0?
There shouldn't be any problem bolting up. Controlling the 42RLE with the 2000 era controls is another issue. BTW, the 2000 on up have distributorless ignition, which is very nice, 1999 and older have distributors with rotor/cap/wires to worry about.

It might be best for you to get an older long block and keep the current controls, if it's the string of 4.0L camshaft issues that has you worried. Actually, only a few people have had the camshaft issues, so unless you have a problem, you should just keep what you have.

The 4.0L I6 has the same bolt pattern throughout it's manufacturing run, same as the 4.2L before it. In fact, the AMC V8's used the same bolt pattern.

If you really want to get rid of the electronics, you're going to have to change the transmission (not the transfer case though). The 42RLE is electronically controlled and needs the engine controls to work properly (I haven't heard of an aftermarket / standalone control for it.) So you could go to a 4.0L from a 1992-1996 XJ with the XJ's AW4 automatic, and it will bolt up to your current transfer case.

For a V8 swap, you'd have to change the transmission anyway, so there are a lot of different options. The Hemi with 5 speed automatic from a 2003-2005 Dodge Ram (non-MDS) is a popular swap, and the electronics are compatible with the 2003-2006 Wrangler instrument cluster. There are a few kits available to take care of the engine mounts and wiring as well (AEV and Summit both offer them). Unfortunately, since they didn't offer a non-MDS hemi in 2006, there isn't any model-year legal swap available for 2006 owners.

There are also controls available for the GM V8 swaps, to adapt the stock instrument panel.
 

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At 91K miles, you are going to replace some stuff. At around 93K on mine, I replaced almost every electronic sensor, coil packs...etc. I do have to agree with you, the newer motors are a lot more finnicky than the 99 and older motors. That being said, I would do some quick math and calculate cost vs. rewards.

-Like others have stated, you are messing with the emissions on a vehicle. Being in Fort Hood, are you in the military? If so, thanks for serving, and you will not stay there forever if you plan on enlisting longer. Say you come to CO, we don't emission test vehicles in Colorado Springs except diesels. What if you end up in CA?
-97 4.0 motor for 500.00 (get the wiring harness and PCM)...and we will just say it is a good motor that doesn't need anything like a rebuild...for now.
-AW4 trans for 300.00 (get the TCM and harness)...and we shall say that is good too.
-Most likely you will have to do some skid plate mods, drive shafts etc...unless they are all the same length transmissions.
-Now you will need to get your dash to work. Go find a old gauge cluster to fit into your dash. you may be able to get yours to work..but doubt it.
-Exhaust mods...they are similar...but you will still need to run the cat and O2 sensor.

-Now lets say you don't get a great motor....and you rebuild it on the cheap for 700.00
-We will say the same for the transmission, but I know better. It will cost way more than that. 700.00

So have you had 2200.00 worth of problems on your 06? This is just the very low estimated costs. No fab time, no supplies, no labor unless you are going to do this all yourself. Most anything in the emissions control you can replace easily or with a little effort.

To me, it sounds like you are heading for a nightmare. I have seen this from V-8 swaps in "whatever" by people getting cheap and not getting a new wiring harness from someplace like Howell for 900.00 and spend the next 6 months in the garage trying to get a vehicle to run instead of hooking up 4 wires and turning a key on. Some people are very successful and do a great job, and don't mind spending the long hours in the garage. I was the same way, not anymore. I would rather wheel.
 

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Discussion Starter #16
Thanks for the response. Your welcome, I enjoy serving. I do plan on retiring here, around in Texas. I just want to simplify my rig. I don't have cool electronic gadgets wired into my Jeep because I believe if it can't get wet and dirty it doesn't belong in it. The few electric add on I have are just a few lights ran by relays. I really enjoy my rig and I think my problem is I try to fix things before they are issues, like on the trail.
 

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OK, so the emissions stuff is out of the equation...and in this case it is good.

You will have to go back to a carburator if you want total electronic free motor...now you are going back in time. Even the motor I gave (97 4.0) still is controled by a PCM that can fail and hates water.

I totally forgot about the fuel system too when you try to change out motors...may be some more cost for aftermaket fuel pump and or fuel cell.

I guess you never really stated what has failed on you or left you stranded on the side of the road/trail..so what has been the issue?
 

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toecutter1978 said:
Thanks for the response. Your welcome, I enjoy serving. I do plan on retiring here, around in Texas. I just want to simplify my rig. I don't have cool electronic gadgets wired into my Jeep because I believe if it can't get wet and dirty it doesn't belong in it. The few electric add on I have are just a few lights ran by relays. I really enjoy my rig and I think my problem is I try to fix things before they are issues, like on the trail.
Start with a CJ or YJ chassis and you'll be thousands of dollars ahead. The TJ was the first digital Jeep even though it doesn't look like it. Just look at the number of things in Chapter 8 of your FSM that end in the words "Control Module". Your drive to replace all of the microprocessors and digital circuitry will require you to replace most of the powertrain (you can keep the axles and driveshafts once you get the lockers under full manual control), all of the vehicle wiring harness, and then you will end up with a collection of barely functional work-arounds for not having the various digital gimmicks. NOBODY makes a kit for what you desire because it would cost more than having a complete spare Jeep. Even if you succeed it will only be after the afore-mentioned years of frustration over a non-running "hanger queen" that was formerly a working Jeep.

I do know a couple of people who tried to do what you describe. One of those folks last wheeled with me two years ago - as a spotter - and the other parted out the dead carcass of a formerly nice TJ.

Considering the number of '97 TJs I see on the trail, it is also wasted effort. All the digital circuitry resulted in Jeeps that run better and last longer than the older models.
 

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Well said Gary. I have even done that myself. My old 97 ended up being cut up with the torch and placed on my flatbed and taken to the scrapyard. It was pretty messed up due to all the stuff I put it though...

My neighbor has a really clean 86 CJ-7, she hated this thing until she put the Mopar fuel injection on. That 258 carb system would always vapor lock, had starting issues etc. There was a number of times she called me to tow her home. Now it starts and runs tops for what she uses it for. The last carb motor I had was in 92 and it was a 84 Chevy truck with a 383 stroker motor in it (shop class in high school was good to me ..LOL), and I would never go back unless it was a drag racing car.
 
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