Turd Bird gets a powertrain swap

[TheBirdman]

Well, I spose I never got around to writing up a post detailing the wiring, and now its been long enough that ive forgotten most of it. Anyways, from what I do remember of it, I got pretty much everything wired up in a way that the cherokee ecu has no idea that its not in a cherokee anymore. The only things missing are the downstream O2 sensor, the battery temp sensor, the fuel level sender, the evap canister junk, the electric fan, and the control wire for the ecu to regulate the alternator. Enough for it to throw a CEL, but not enough to keep it from running well. Also the VSS is working, but its off, becasue there is no speedometer gear big enough to make 2.35 gears accurate on this setup.
Speaking of which, I actually have the cherokee instrument cluster and OBD2 port installed too. Its a real treat. A couple issues I had were that I needed to wire up the cherokee brake light switch, as the TCU needed that signal to know when to lock up the torque converter, and also I found out a few months later that my throttle position sensor was worn out, it was only reading 30% throttle when I had it floored, so it really picked up some speed after that repair, haha. The high pressure fuel system made from cheap oem parts works flawlessly, and the only thing even close to an issue is that the OEM style eagle tank starves the pump on right turns if Im driving on an almost empty tank. If anyone is working of a EFI swap Id highly recommend this setup.

With all that said, 2.35 gears have become rather annoying, so if anyone has a 2.72 or up front axle, shoot me a message.

[Illeagle1984]

Thank you for the great writeup on some of the finer points of engine conversion.  Applause for the fuel system, it's a great idea.  The idea of hooking a modern scan tool up to an Eagle is intriguing...

[TheBirdman]

It sure is intriguing. When I was troubleshooting the throttle position sensor, I was able to go down to the local parts store and borrow their fancy scanner to read the throttle % PIDs live while I was messing with the sensor. Very handy, and I also got a couple deliciously inquisitive looks. I can also plug my bluetooth obd2 reader into it and get all sorts of live gauges on my phone while going down the road.

[maddog]

I'm the doing the OBD1 route myself because it's simpler and electrical is not my thing mechanical is. One issue I'm having is that I've got to figure out what wires go to what so I can splice the Cherokee harness into the eagle plug. And no I'm not going to destroy a perfectly good harness to do this I'm using one that was messed up in a fire and has some serious damage to it.

[TheBirdman]

With how few sensors and things there are on an OBD1 setup, you could probably just keep the cherokee harness separate from almost all the eagle wiring. One thing youll probably run into is that the cherokee wiring is going to want a wire from the ignition that is hot in both run and start, and the eagle ignition has one thats hot in run but not start, and one thats hot in start but not run. I know theres some way to fix that with a diode, but like you Im more of a wrench guy than a soldering iron guy, so I just wired in a pushbutton to the starter relay. Anyways let me know if you need a wiring diagram for either setup, Ive got all of them now.

[Billman]

Now that you've proven your hypothesis, you can come over to my garage and finish up mine.
i dropped in the engine, trans, transfer caser and rear axle from a 95 cherokee into an 83 Eagle wagon.
if you still have your schematics, I would appreciate a copy so I can get to the wiring part of this project.

[TheBirdman]

Sure thing, Ill be right over
Basically what I did was print out the wiring diagram for the cherokee, one for the eagle, a pinout of the 3 plugs on the pcm, and made a list of every wire the cherokee system needed, got a few spools of wire, and just did it one wire at a time. Ill see what I can dig up of my documentation.