Wiring Harness for 1994 YJ 4.0L Engine Swap Into a 1982 Jeep CJ-8

[Nacj8]

I recently ordered you book Jeep cj rebuilder's manual. It is due to arrive June 21. I am putting a 1994 yj 4.0 engine into my 1982 cj8. I did this about 20 yrs ago and used hesco harness. They don’t offer this any more but it looks like I can order one from mopar performance with the same part number p5007148 as the old hesco number. Would you have any idea if they are the same. Any help would be appreciated. Thanks, Bill Himelright 

[Moses Ludel]

Hi, Bill...Thanks for your interest in my book...Your engine year is right for the 60-way PCM (1991-95 YJ Wrangler 4.0L).  The 1995 YJ Wrangler 4.0L two-rail EFI was the original prototype for Mopar's first generation Mopar EFI Conversion Kit. 

Second generation Mopar EFI Conversion kits use the 1997-99 single rail fuel injection/induction system with a modified pressure regulator (1997-up style mounted in a machined remote housing).  The second generation kits still used a 60-way PCM (1991-1995 style).  The Mopar wiring harness should fit a 60-way PCM like the one that came with your 1994 4.0L engine.  If you got the PCM with the engine, you have the 60-way (60-pin) PCM. 

I did a quick search and found the Mopar parts listing at the link below.  It shows a P5007148AB wiring harness that replaces both the P5007148 and P5007149 harnesses.  The price seems competitive:

https://www.moparamerica.com/oem-parts/mopar-harness-p5007148ab

This image for a P5007148AB harness appears to be a 60-way.  Note that this harness has the single 60-way/pin plug connector that you need for a 1994 donor PCM.  The wide plug with a bolt through the center is 60-way:

This Mopar Performance harness number should accommodate both the later single-rail or earlier two rail EFI kits.  If the PCM connector is 60-way/pin, this should work with your 1994 engine and 1994 (1991-95 style) PCM.  

Your two-rail EFI system requires a return fuel line to the fuel tank, which is not an issue.  Your '82 CJ-8 chassis has that provision.  When you receive your copy of my Jeep CJ Rebuilder's Manual 1972-86 (Bentley Publishers, available at Bentley Publishers, Advance Adapters and other book outlets), you will find coverage and details about the two-rail Mopar EFI conversion kit installation.  I did that conversion with an '84 CJ-7 Jeep, using a first generation, two-rail Mopar EFI Conversion Kit.  The approach will be similar for your 1994 YJ 4.0L EFI engine if you have the original donor EFI/induction system, ignition distributor and PCM.

Let us know how the wiring and overall conversion turn out.  This should be a significant improvement whether the 4.0L remains stock or becomes a 4.6L stroker build.  If you are considering a 4.6L stroker build with your 258/4.2L crankshaft, the fuel injectors should be upgraded to 302 Ford H.O. type for adequate flow rate.  I cover this in detail at the magazine, including injector tuning.  Do a key word search for "4.6L" at the magazine. 

Moses