Turd Bird gets a powertrain swap

[TheBirdman]

To begin, I dont want to clog up this thread with duplicate posts, so for an overview on the car up till now, refer to this link:
http://forums.amceaglesden.com/index.php?topic=46603.0
I started a thread for my np242 swap, but after getting to the junkyard and seeing such a nice 96 cherokee (I thought it was a 95 at first), I decided to pull the trans and wiring harness out of it and finally get the fuel injection working. here is a link to the np242 swap thread, which contains a real informative writeup by amarshall:
http://forums.amceaglesden.com/index.php?topic=46609.0
Since this is turning into a much bigger project than just transfer case swap, I figured Id use a thread here.
Anyhoos, when I first swapped in the 4.0 (from 93 chero), I transplanted the entire eagle accessory drive and intake, to make the swap super easy at the time. I kept all the 4.0 parts in a box, and since then its had a mc2100 and HEI swap, and while it runs like a charm in nice weather, or after warmed up, its still a cold blooded bear when the temps get down below 20F. Ive always wanted to get it back to fuel injection, and now is the time. Well, now is subjective, what with life things going on itll probably be a few months till I have the money and time to complete it, but what else is the point of a project car, right?

So far, Ive pulled the transfer case, transmission, throttlebody, pcm, tcm, engine wiring harness, and the section of chassis wiring harness that contains the tcm wiring, along with assorted brackets and sensors. Ive found a FSM for a 97 cherokee, which as far as I can tell is pretty much the same as 96, so good enough for me. Ive made a spreadsheet from the pinout of the pcm, and went though noting which inputs are needed, which arent, and which I will have available after all the guts are swapped in. There are some things I cant tell if is needed or not, so in the current researching phase of the project, I am trying to nail down which inputs I can cut out and not affect engine performance. I Know the wiring would be easier if I had gotten an OBD1 pcm, but the junkyard didnt have one, so Im tinkling with the pickle ive got.

Ill cross these out as I figure them out, but if anyone has any knowledge or tips, let me know.

A25 - K141 18TN/BK -  DOWNSTREAM HEATED OXYGEN SENSOR
Its hard to find any solid information on this one because of all the stigma online about discussing emissions systems. Some say the downstream sensor has no effect of fuel trims and timing, and only sends a CEL to complain about the cat being worn out (I will not be adding a cat to the eagle), and some claim the pcm will mess with fuel trims to try to prevent further damage to the cat.

B10   K20 18DG    GENERATOR FIELD DRIVER
C25   K72 18DG/OR    GENERATOR SOURCE
I have the v-belt internally regulated alternator from the 4.2 on the engine, so I dont need to have the PCM regulate it, but I dont know if the PCM will run correctly without this hooked up.

B23   G60 18GY/YL    OIL PRESSURE SENSOR
I have the old style oil pressure sender that controls the dummy light on the dash, as well as an aftermarket oil pressure gauge, so I personally would prefer to continue using those, but I dont know if the PCM will run correctly without this input.

B27   G7 18WT/OR    VEHICLE SPEED SENSOR
The transmissing control module uses the VSS on the trans, and the PCM uses the VSS on the tail of the transfer case. Id like to convert the NP242 to cable speedometer drive so I can use the stock eagle speedometer, but again, I dont know if the PCM actually uses this input in engine management, or just to report to the factory cherokee instrument cluster.

C15   K118 18PK/YL    BATTERY TEMPERATURE SENSOR SIGNAL
I definitely dont have one of these, and logically Im pretty sure its not needed, but I cant be 100% sure.

C20   K52 18PK/BK    EVAP/PURGE SOLENOID CONTROL
same story as battery temp sensor

C26   K226 18DB/LG    FUEL LEVEL SENSE
pretty sure I dont need this one either, but worth mentioning

C24   K29 18WT/PK    STOP LAMP SWITCH SENSE
I dont have this circuit, but Im sure I could rig one up if needed. The wiring harness for the tcm uses this as well, but I dont know if that is just to prevent the stock cherokee shifting out of park without brake, or if it is actually used in engine management.

C27   D21 18PK    SCI TRANSMIT
C28   D2 18WT/BK    CCD BUS(–)
C29   D20 18LG/BK    SCI RECEIVE
C30   D1 18VT/BR    CCD BUS (+)
These are for the obd2 plug under the dash, as well as connecting to other computers like the tcm. I dont believe they are needed, but if might be fun to hook them up for kicks and giggles.

I also wasnt sure if all the wiring for the 96 would work on the 93 intake, since they are the different types, but I grabbed the 96's throttle body and sensors to be on the safe side.

Ill update this thread as I make progress, slow as it may or may not be.

[mick]

I'll definitely be keeping up with this thread.

[Taylor]

Looks like another good thread to watch. I love a good project.

[Billman]

you have piqued my interest as well.

[eaglefreek]

In your other thread, you stated you may go with an AW4. If so, you are going to want to plan on swapping differential gearing. With my AW4 swap, I had 3.55's, but believe 3.73's would have been better. However, I didn't have a 4.0L. I had a 258 with a 4.0L head with a carb.

[TheBirdman]

It's been a few weeks, but I'm not dead yet. I went back to the junkyard again and i got the entire intake after discovering that thedonor jeep is infact a 1999. I also nabbed the distributor and coul since my 93 ignition wouldnt work with the 99 harness. Aside from that i grabbed the aw4 shifter that i forgot, the brake swith, obdii port, and a few other goodies. I was going to get the trans crossmember too, but i forgot. Ill probably have to make that from scratch anyway.
Ive done a little more reading of the wiring diagrams and pinouts, and i think im sitting pretty good on things, but i havent had the time to get everything started yet. The main things i need yet area novak shifter for the 242, a vss from a dodhe dakota, so i can get cable and vss output from the tc, a new o2 sensor, and a few random bits and pieces.
I did get a little practice in on rebuilding wiring harnesses, as i had to replace a run of the high speed canbus network on my crown vic.

Maybe ill get around to fitting things together in another month or so, after some home improvement projects.

[amarshall]

Good update, thanks for keeping us posted.  This sounds like a lot of work!

[TheBirdman]

Still no real progress done, but I've got a little more napkin engineering ideas for the fuel system. Im thinking on the frame rail near the tank, relocating the clickety clack low pressure pump to feed an "EX2000" style inline high pressure pump common from 80s fords, then from there, into a fuel filter/regulator from a 99 grand cherokee, since they ran at the same fuel pressure as my 99 cherokee pcm and fuel rail. Still not completely sure what Ill do for high pressure line yet, but Ill figure that out later. If this setup works, Itll be great to have a FI swap ready high pressure system made from cheap old OEM parts that can be replaced at any auto store, instead of $300 aftermarket pumps, regulators, and filters.

[TheBirdman]

Work Begins!
Over the past week Ive begun my project, whenever Ive got the time. First, I removed the manifolds, transmission, shifter, transfer case, TC vacuum system, cec, cruise control box, any old wiring that had previously escaped my tinsnips wrath, and whatever else I wouldnt be needing anymore. The first step is to get the transmission and transfer case in, and everything else can be built around that.

Ive decided to go with an Iron Rock Offroad hack n tap slip yolk eliminator, to allow my to use the stock eagle driveshaft. With the output shaft of the np242 cut down the shortest the SYE will allow, the AW4/NP242 combo will be exactly the same length as the TF998/NP129 combo, give or take a quarter inch. The front yolk is about an inch further back, but there is enough expansion in the front driveshaft that I dont foresee any problems using it.

Next, I fit the cherokee shifter in. The hole in the eagle trans tunnel is slightly larger, so I cut out and riveted a small steel piece to fill in the gap. The left two holes match perfectly up with the old setup, so I only had to redrill holes for the right ones. The new shifter is a cable type, so I cut out a hole in the firewall next to the AC drain hole with a stepper bit and a rotary file. The grommet on the cable fit very nicely.

When I went to put the new transmission in, I found that the separator plate for the TF998 didnt quite fit the AW4, so I had to cut a bit off and add a little to the AW4 inspection plate to make it all fit. I do hope the plate for the AW4 is the same thickness as the TF998, otherwise I may have some problems. Does anybody have an AW4 who can check?

Tonight I got the transmission and transfer case in and bolted up. I spent most of my time crawling around trying to install them individually with just a floor jack and one person, and fiddling around with an angle finder trying to figure out what angle I should fabricate the new crossmember for. The pinion angle is around +8 degrees, which is way too high, and explains my high speed vibration. I blame the clapped out leafs. Ill put it on my list to shim the axle down to something more reasonable, but for now a little ujoint vibration never shot down an eagle, right? In the above pic Ive got the tranny at about 5 degrees, Ill have to do a little finesse work with the 5 lb ball peen, but I think I can get it up to 4 or maybe even 3 degrees, I want all the ground clearance I can get.

In the next few days Ill see if I can get the trans crossmember fabricated and the trans/TC mounted for good, then I can move onto the fun stuff that doesnt involve smashing my thumbs under 100lb slabs of cast aluminum. Truth be told, Ive been so excited to wire this thing, when at the beginning I though Id be dreading it.

[TheBirdman]

Oh hey, here another question for you guys. I sort of butchered the sun bleached carpet getting to the shifter. I see on rockauto there are a few options for new carpet, and the option for the 2 door is almost half the price as the one for the wagon. From the pictures it seems like the 2 door captet is the same thing without the hatch carpet, but I was wondering it anyone knew if the SX4 carpet would fit in a wagon?
https://www.rockauto.com/en/catalog/american+motors,1983,eagle,4.2l+258cid+l6,1003396,interior,flooring,1264

[RallyEagle]

Nice project!  Cant help with carpet question but consider a transmission jack.  They are very useful.

[TheBirdman]

Eh, Im getting pretty decent with just a floorjack. I got get this thing in and out in 15 minutes on my own now




I welded some junk onto the cherokee crossmember to fit the eagle, as well as welded another crack in the header and added a second o2 bung


For the transfer case shifter, I decided to use the cherokee shifter, with an aftermarket linkage, specifically Boostworks Engineering 242 HD Shift Linkage V2.0. I still need to make it not have giant gaps in the floor, but it works and shifts nicely.

[TheBirdman]

Update time I suppose
I must have cracked the intake when I was taking it off the jeep

so I broke the chunk completely off, filed some channels in it, stuck it on the bbq, and went at it with an aluminum brazing rod


It was hard to keep the temperature high enough to finish the job with brazing rod, so I finished it off with JB weld, before sanding it smooth


The wiring harness looks pretty simple just laid out on the floor

Most things fit pretty nicely, all things considered. I had to cut the top of the power steering bracket and bend up a new piece to weld to the bracket to bolt onto the intake, and Ill need to relocate the coolant overflow and wiper fluid tanks to fit the airbox, but no biggie in the grand scheme of things.




I had ordered some M14 to hose barb fittings so I could run rubber hose for the trans cooler, but they didnt have a wide enough shoulder to seat the oring properly, so rather than scour the internet for another set or waste a day driving around looking for something overpriced in town, I ground them down at a beveled angle so they sat nicely inside the stock AW4 fittings, then gave them a healthy does of JB weld as well


After that, I got the new fuel system installed, I drilled and tapped the frame to bolt everything on. Ive got a walbro low pressure high volume pump used in old ford B600s, an E2000 inline high pressure pump used in 80s ford pickups, and a filter/regulator from a 90s grand cherokee. Im hoping this all works, because afaik a high pressure fuel setups for FI swaps that cost under $50 (not including fuel line) is pretty much unheard of.


While I was running the new trans cooler lines I took the opportunity to clean out my radiator and trans cooler, unbend some fins, and give them a light fog of black header paint, should look nicer behind the black grille now. And if you want to get technical, it should cool slightly better too.

[mick]

That's looking really good!

[TheBirdman]

Well, good news is its up and driving, and boy is it sweet. Bad news is now Im too busy enjoying it and finishing up the wiring to do a proper post. Ill get to it soon.

[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.