318 in a YJ

[A BOM]

History: A friend of mine has installed (mechanically speaking) a 318 ZJ engine in his YJ. He is not very electrically inclined and rather than paying someone to merge his YJ & ZJ wiring harnesses, he asked me to help him.

We are ready to go mechanically. Electrically, we are slightly past just getting started. Has anyone here had any experience with this swap / conversion? If so, any information, warnings, recommendations would be greatly appreciated.

Thanks, BOM

 

[jps4jeep]

Honestly, I make no assumptions of your skill... Call someone, Spend the money and buy a pre made harness that is plug and play. I have made a couple harnesses in my time, not easy, not fun. Yes it will cost you, but I bet it is worth the price when your rig runs right and doesn't burn to the ground.

Having said that.. How I have made harnesses in the past. Get the Factory Service Manual for 1. the vehicle the motor came from 2. the vehicle the motor is going into (right there, thats about 1/4 of the cost of a pre-made harness) you will also have to most likely get a Dodge ECM from a 318 equipt with a manual unless your re-using the ZJ auto transmission. As far as I know, the ZJ's only had manuals behind the 4.0's, (now your at about 1/2 the cost of the pre made harness.) then you will just need to go through and match the wires up, make sure you take notice for Ohm's and directional flow, adding resistors and Diodes where needed.

 

[A BOM]

Thanks for the input jps!

I have access to the ZJ & YJ manuals. The 318 was installed with its auto trany attached as well as the original 318 ECM.

As for my skill, I am quite fluent in electronics, but not so much in Chrystler vehicles...

 

[Saddle Tramp]

I think Four Wheel Drive & Sports Utility (if not them then it was JP) did that swap a number of years ago. Google them and see if it is in thier archives.

 

[volaredon]

exactly the swap I was wanting to do when I had my YJ (but the wife wanted something bigger; so I got the XJ for her to drive; when we had the 2 Wranglers, the TJ was "hers" and I was the one to put up with the underpowered 2.5 while she had the 4.0)
I like the XJ other than the "extra" doors; (I'm not a 4 door fan) I miss the days of having both a TJ and a YJ in the driveway. When it came to driving in a cross wind, my YJ was way more stable and less "all over" the road. Less of a "handful" to keep on the road than the TJ.

 

[Saddle Tramp]

When 4 Wheel Drive & SU did the swap one of the things they like about it was the prime torque band on the 318 was right in the sweet spot around 1500 to 2000 rpm as I remember.

 

[A BOM]

It runs! IT RUNS!

Electrical is by far NOT complete, but it runs and runs well. Just gotta perm mount everything and pretty up the wiring.

The only 'snafu' encountered was a few hour troubleshooting bout with the PCM. Final result was a plug not properly connected (you gotta tighten that screw on the male end to ensure proper connection). Other than that, pretty smooth sailing.