mjeff87

Not a difficult swap, just a lot of work and a bit time consuming. Like Eagle said, all the 4.0 stuff is bolt-in, you just have to get the right parts. I used an ’89 MJ (automatic) underhood wiring harness and simply plugged it into the bulkhead connector for the stock interior harness (did A LOT of research and pinned out each circuit to make sure it would work). In addition to the harness, you’ll need: -4.0 ECU (grab this when you get the underhood harness) -4.0 frame horns (they bolt onto the framerails and the correct holes/studs are already there) -4.0 motor mounts (2.5 ones are smaller) -4.0 radiator and hoses (remove the 2.5 radiator brackets and the holes for the 4.0 rad are already there) -coolant resivoir or some sort if you run an open cooling system (I reused my 2.5 one with some modifications) -4.0 fuel pump (2.5 may be enough psi to start it, but won’t push enough volume) -4.0 transmission (AX15), new flywheel, clutch, pilot bearing and transfer case (23 spline) -new driveshafts, front and rear You’ll also have to splice the 4.0 fuel supply and return lines to the 2.5 lines….for whatever reason the 2.5 lines have a connector where the rubber lines meet the hard lines on the framerail, but the 4.0 lines don’t. I just disconnected the 2.5 lines at the connector and slipped the rubber fuel lines over the hard lines and double clamped them. I also reused the 2.5 MAP sensor and ICM, they are the same parts for both engines, interestingly. Jeff

definately sounds like something is heat soaking, I agree (that's why I thought of a weak relay). Did you swap ICM's to see if that helped? Jerry (tjbliley) was having the same random problem with his 2.5 rig awhile back....we ended up troubleshooting it to find out that one of the wires going to the TB injector was loose and intermittently loosing contact. That was a fun one to figure out.

weak F/P relay, or loose wire maybe? Jeff

Had a little incident last weekend, the stupid little u-clip that holds the hydraulic line into the internal slave/throwout fell out and the line popped out, rendering my clutch useless (as I was driving down the road @ 45 mph). Got it back down to the garage, pulled the tranny back out and replaced the u-clips with cotter pins ;) Got the tranny/TC and crossmember back in last night after work and got the clutch bled again. Still have to put the starter back in, hook up the TC linkages and rehang the driveshafts, but it'll be back on the road again tonight (I hope) replaced the u-bolts with cotter pins, neither line will slip out again….. Image Not Found quick shot of the new clutch package while the tranny was out: Image Not Found

Had to have a shaft cut for my MJ to about 42.5", running an AX15 with D44 (SOA). The longest XJ shaft I found in the 'yard was 40" (AW4, D35). Jeff

well, I drug the MJ back to the storage facility on Sunday and went down yesterday and dropped the tranny. Slave is fine......but the BS little U-clip that holds the input line into it slipped out and the line popped out of the cylinder :oops: . Replaced both clips with cotter pins. I'll put it all back together tomorrow, if I get a chance. I might take a sick day from work, 'cause I have to be out of the place by the end of the month or else I have to fork over another rental payment. Jeff

I've got a gray one you can have if you want it..... Jeff

Cleaning out the storage facility today, running parts/tools back up to my house....unloaded and was heading back down, lost clutch. Limped it home in 4th (luckily not alot of traffic out today) and parked it beside the house. BRAND NEW internal slave, blown :headpop: Anyone got an AX15 external slave setup for sale? I have the BH, need all the rest, quick..... Jeff

^^^^^^^^^^^ Gaaaahhhh!! my eyes!!!! I've been blinded!!!! ;) Wish I had a pic of mine when I first got it back in ’99, but digital cameras weren’t even invented back then :D It truly was an “old man’s” truck (and I bought it from him, sort of....he passed away and I bought it from his wife). Here’s a comparison of right after I converted it to 4WD and brought it back down to VA, to where it sits now. Lotsa stuff has changed….. Back then: Image Not Found Image Not Found Now :brows: Image Not Found Image Not Found

you won't need the bulkhead engine-side, but you'll have to pull the entire interior wiring harness because it is all hard wired to the fuseblock (woulda been nice if they would have used pigtails out of the box to some connectors but they didn't). I've got an '89 MJ interior harness that I ended up not needing for my project......I'll let it go to you for cheap if you can't find one down your way. Jeff

cam position sensor is in the dizzy, the connector for it is in the secondary harness that goes to the alternator and starter, over by the relay center. If that's an HO harness, the CPS connector is round like your third pic. The renix CPS is flat (looks like the MAP connector). Look at your CPS and see what shape your is. Jeff

first pic, I didn't use either of those connectors. I think one of them is for the optional underhood light second pic, MAP sensor third pic, looks like the CPS connector to me but I'm not sure. Jeff

What's the Canuck Conferedate flag look like? :D Same as ours except it has a moose on it drinking a beer and playing hockey..... ;)

yes, it's slightly different. I found this out the hard way recently when I swapped an AX15 into my rig......dimensionally they are identical, but in the center of it where the tranny mount bolts the AX15 crossmember is dished out by about 1". I tried using my original AX5 mount, which is the same part # as the AW4 and BA10/5 mount that wasn't dished out and the AX15 sat 1" too high. Couldn't get the TC linkage to hook up, and my cat converter was hitting the floorboard. See the bottom of page 4 of my build thread for a pic of what I'm talking about: http://comancheclub.com/forums/viewtopic.php?t=11205 Your swap worked fine, but you could probably swap the AX15 crossmember you have with an AW4/AX5/BA10/5 one and raise your tranny up a tad in the rear. But if it's all working good, I'd leave well enough alone ;)

you can use an auto TB with a manual, just leave the second pigtail on the TPS disconnected ;) Jeff

I'm thinking the rings need to reseat is all, like you said. Been driving it around locally and it looks as though it's starting to tighten up a bit already. Not sure if I want to go to 35's or not. I really dig the power in 1st gear with the 33's, especially in 4LO :D I was pretty twisted up when the TC jammed, had my right side in a 3 ft trench....I'm guessing the craptastic factory linkage wasn't very happy when I tried to shift it......

got it all put back together and took it on a maiden voyage Saturday night, good highway trip with some minor wheeling to a spot in the woods to watch a CJ get very stuck. Got a few minor issues......fuel pump sending unit is leaking (the o-ring slipped on install), transfer case got stuck in 4HI for a bit then popped out quite unexpectedly (lotsa scary noises there :roll: ), and I have a moderate case of blowby to diagnose. It didn't help that I forgot to connect the air tube to the airbox securely, which came loose and dumped gobs of oil all over the frame/steering box. Other than that, which I'll fix this weekend, it runs and drives great. I could very easily run 35's if I wanted/needed to. On the highway @ 65 I was taching around 2600 rpm in 5th. Gonna do an oil change this weekend, going with 10W40 (oil pressure dropped but remained steady at 25-30 psi) and add a can of Restore. Jeff

yup, keeping my original 87 assembly as a spare.....the 91 unit I pulled is alot less coroded. Jeff

probably not, but I'm not using it as a sealer in this case. The tubes are in good shape and not cracked/leaking, I just added the JB to add some rigidity to them, so that they don't end up cracking down the road.

Forgot to post this earlier……pic of the difference between the 2.5 and the 4.0fuel pumps (2.5 one is the smaller one on the bottom). I was going to try and see if the 2.5 pump would have enough psi to fire but went ahead and swapped everything out beforehand. I wasn’t sure it was going to start to begin with, and didn’t want to add a variable to the equation if I had to troubleshoot. differences: Image Not Found because MJ fuel pump assemblies have a tendency to crack where the metal lines pass through the mounting plate, and they are universally unavailable anymore, I decided to add a bit of JB weld to the lines on the new assembly before putting it in as a safety measure: Image Not Found

Gut that cow and go V8....you know you want to. Five wires and it will run. I'm still thinking it would have been easier for me to swap a 340/360 into mine than the 4.0 I did :roll: Jeff Image Not Found

Make sure you have the correct CPS and flywheel to match the harness. Look at the CPS connector on the harness, if it's round it's OBD1 and if it's flat it's Renix. You can't switch them, as far as I know but you can swap flywheels to match the correct CPS for the harness if your's isn't the same. Jeff

got the rear shaft on it last night after work and took it for a good spin around the storage facility. I can spin the 33's from a dead stop :chillin: Jeff

Pull straight up on it.....carefully. It's just a snug press-fit, but when it releases from the shaft, you can hurt yourself ;) Jeff

That was the good side Pete.....the driver side is smashed worse :roll: JT, the whole roof is/was custom, not factory. Look at the first pic I posted and you can see what I mean. I can get info on the sunroof, but not sure if it would be worth anything for ya. Like I said, the more you look at it, the more weird things you see.... Jeff