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Swap from HELL!!!


NAXJA Forum User
So I decided to do a swap on my daily driver before the summer began. A 1998 tj. I took out the 2.5 manual and swapped in a 94 zj drivetrain. Which is a 4.0 and 42re. I ended up having the motor, transfercase, pcm, and tcm. Which I thought would be plenty to get it going. Boy was I wrong..
So it's been six months and I'm still having technical difficulties. I've bought a radiator, complete engine wiring harness, and another pcm. As well as a few other things I'll touch on in the words to come.
To make a long story short, I have it the the point where it fires up but immediately kills the injector pulse. After a few weeks of searching and reading on the web I have came to the conclusion that it's the pcm not having can bus communication with the alarm module.
I'm flat broke and almost out of hope. I buy a new used general pcm without security from beards Midwest jeeps. Theses guys have saved my bank on parts for this swap. Turns out it is not the problem.
I read somemore about bypass modules. And was actually going to the junk yard to find a decent carb to try n get work when I came across a 91 xj Laredo. I bought the pcm and complete dash wiring for $20..
I am still using the tj dash wiring. My question is should I take it all out and swap in the xj wiring harness. Or should I try to separate the xj alarm module and wire it in to my current setup. Are the security modules plug and play? Or would I need to have my pcm flashed. Say I use the xj pcm, and dash wiring. Would my zj tcm communicate with it?

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There is a fellow on the Jeep Forum called WATERLUVER he’s in the WJ section. He’s capeable of removing the Skim from some modules. Perhaps he can help.I woul think staying with the ZJ PCM would be best as it can talk to the TCM . He does good work fast and is in Indiana so close to Illinois. He could probably add your Vin to it if you need emissions. Or you get a PCM that does not have a Skim module from another ZJ

I have tried 3 different pcms. The only thing I haven't tried is a security bypass module. Is there a cycle of checks the pcm has to clear to run correctly? Like a preshift inspection on can bus. I know it's a long shot but I'm desperate.