4.0 swap into CJ, any advice?

[JEEPINKC]

I am planning to swap the 4.0 from my TJ into my uncle's CJ.

The TJ will be getting a SBC.

Anyone have any experience with this swap that could save me a headache or two down the road?

It looks like a fairly easy swap as far as the nuts and bolts go.

The electronics are going to be my biggest obstacle.

Any advice would be greatly appreciated.

[rustinh1]

You need the computer from the TJ donor and really you need the wiring harness. You could also swipe the harness from a newer XJ at the salvage yard if you don't want to take yours out for obvious reasons. With the SBC, are you going to advance adapters for their fuel injected conversion kit?

Another avenue for the harness would be to call painless and just have them build you a harness for the 4.0. Believe me, trying to piece together a harness yourself is definitely not worth the money it would cost you to buy one!

Oh yeah, you may want to graft the dash/gauge cluster into the CJ as well or just cut apart the harness at the cluster and tie all the individual leads to autometer gauges or similar. Definitely contact jeep or do some digging for a wiring schematic for your tj so you know what each wire is leading to sensor wise!

[chem57guru]

If you are going to use your entire drive train, electronics, and computer in the CJ from your TJ it will easy. Once you start mixing components from different eras you will start a snowball of headaches that will turn into a nightmare. The first porblem that I see is how are you going to adapt the instrument cluster gages from your TJ wiring Harness to your CJ? Now granted everything I just wrote is dependent on you doing a straight swap. If you are just planning on using the engine itself and nothing else then this might be easier. I am now, hopefully, on the down hill slope of swapping a 4.0 into my TJ and it has taken 5 months of headaches and obstacles and nightmares. BEFORE YOU DO ANYTHING FIGURE OUT EVERY POSSIBLE WIDGET AND HOOYAH THAT MAY COME UP! I didn't do this and have paid the price.

My $.02

Paul

[bwiencek]

Go carburated....

Just kidding... I just completed an XJ engine into my YJ and the wiring was really easy - the OBD-II stuff might be a little harder though - I didn't check into that one. Just do some searching on the forums - I think you'll find most use the factory harness. OH - and the TJ speedo is electronic so you'll either need an electronic (autometer) or do a wierd cable passthru from the transfer case's speed sensor....

I used the complete engine side harness for the XJ and spliced a couple wires from the YJ into it and everything seems to be working good - only have 50-60 miles on it right now, but it's been good so far - we'll see once I get 'gutsy' to take it on a 50 mile r/t to work a couple times then I'll know it's good...

[JEEPINKC]

Thanks for the input!!

The CJ will only be getting the 4.0 from the TJ.

From what I have read, I really need to get a donor harness and computer. I don't know for sure what models and years may be adaptable. I am thinking 92-95 YJ or TJ with a manual transmission would be best.???? XJ's should be fairly easy to find also.

The TJ is getting a Camaro TPI 350 and 700R4.

The swaps should be somewhat similar as the computers and harness' will have to be grafted into each.

Keep the ideas coming I will need all the help I can get.

[bwiencek]

Thanks for the input!!

The CJ will only be getting the 4.0 from the TJ.

From what I have read, I really need to get a donor harness and computer. I don't know for sure what models and years may be adaptable. I am thinking 92-95 YJ or TJ with a manual transmission would be best.???? XJ's should be fairly easy to find also.

I'd guess the XJ harness/computer would be the easiest - XJ's with the auto trans will work they just need the "neutral start" pin grounded for the starter to crank (otherwise it thinks it's in gear). There are OBD-I XJ's out at Pick-A-Part all the time and fairly complete. The sensors would be what I'd be worrying about if you wanted to use the early 91-95 setup... I'd probably grab all the sensors with the harness and computer.

It's only 3 wires to get the XJ computer to run the engine, and if it 'was' an auto and you've got a manual then you need to ground that wire.

Here are some swap links that I found when I was looking at doing mine...

http://www.madois.com/html/tech/40swap.html

http://www.wilhelm-tech.com/jeep/mods/40EngineSwap.htm

The CJ Offroad forum has a lot of great info....
http://www.cjoffroad.com/forums/topic.asp?TOPIC_ID=4410
http://www.cjoffroad.com/forums/topic.asp?TOPIC_ID=6408

http://www.jeepforum.com/forum/showthread.php?t=250920

Also - I collected early YJ and XJ wiring harness info if you want to go that route...

[charlieduv123]

i dont know a lot about this swap just thought i would add i put a clutch in a 05 tj and if i can recall i broke the engine speed sensor that was on the bell houseing of the tj and the fly wheel had a exciter ring on it and it would not start with out it there i dont know what year you are working on but i know that could be a snag either way if you use the trans and box off the tj the cj is pass drop front and the cj trans might not work but the one i was working on was pretty new and yours may not be the case

[JEEPINKC]

CJ 4.0

I am getting closer to this swap happening.

4.0 and harness are in the shop now, just waiting for the Jeep to show up.

I need to know if anyone has drilled their own bellhousing for the crank position sensor.

If so, how did you go about doing it?

Thanks