Green Mesa XJ

I don't think the 87-90 had a fuse box there like the 91-up XJ/MJ did, looks the fuse relay box the Renix had is there but I'm more familiar with the 84-86 v6 and 91-94 4.0 HO XJ. Did a quick search on Hollander parts (used parts), looks like J&W may be the folks to call, they specialise in Jeeps, they also show several engine harnesses for 87 Cherokee and one is exactly a 87, 4.0 automatic 4x4, (stock # 648U) here is a link for the search https://www.hollanderparts.com/used-auto-parts/1987/jeep/cherokee/electrical/648-engine-wire-harness/648.am8287-alternate-engine-wire-harness This is the search result for the harness from that 87 stock # 648U (on car parts.com they show $250) https://www.hollanderparts.com/used-auto-parts/1987/jeep/cherokee/electrical/648-engine-wire-harness/648.am8287-alternate-engine-wire-harness/part-212717-4686-1 At car-part .com search, they don't have a listing for engine harness you have to look it up as " Electrical Part Misc and Wiring" then read the descriptions to find what you're looking for. Keep in mind you might be able to use another year but there is no guide I know of to make sure it will work. http://car-part.com P.S. Why does the font size change so much?

Is it possible that battery acid melted that? Sent from my iPhone using Tapatalk Pro

You absolutely need to figure out they why it melted, far as I know it’s unusual for a renix era jeep (87-90) to do this, was there a fire ? My phones not loading the full picture of the damage but I see something on the thread just can’t tell where it is. I’ve tried fixing cars with harness damage, unless it’s very limited in scape I’ve found it better to replace the harness with a good used part. To many gremlins to hunt down. For replacement locating a engine harness for the correct year with correct accessories is the surest fit with least hassle, you might be able to go up the years, I dunno the changes through the years. eBay and car-parts . Com and Hollander parts are search engines for used parts, it’s a pit of a pain for electrical items like this because the interchange is unknown because Jeep and others don’t really have this data in their parts catalogs . Depending where the damage is you might be able to replace the section of it by unplugging it at the factory junction ports. On the renix I’m not really sure how many sections there are. But if you have to replace the part that goes to the fuse box make sure you match the main bulkhead pattern, this might be the wrong technical term, but through the years jeep changes the that huge plug at the firewall where it connects to the dash harness and fuse box, I think much of the renix era might be the same but there no reliable information about interchange so it’d be best to stay in you year for that particular part unless you get a complete engine and dash harness together from a donor vehicle. Sent from my iPhone using Tapatalk Pro

You can get plenty of power for accessories including headlights but not have the juice to run the starter because of battery cables. My 85 XJ did this to me a few months in to ownership, young kid with a old jeep and a new battery couldn’t figure it out at first because the cables looked ok on the out side. Sent from my iPhone using Tapatalk Pro

I looked the part up on manufactures website and it looks the same, D2100 interchange is 85-86 only jeep, Chevy, olds, Pontiac, Buick , 2.8 carbureted , 4 terminal module, without EST system Which is correct for a non California 2.8 jeep. I think rock auto had the wrong parts description. If you get one and it is correct with the wire to the ignition coil I may buy one just for that damn wire, it’s 85-86 gm carbureted vehicles only so far I can’t find a replacement part #.. Before 1984 Chevy had a different flat spade terminal ignition coil. Which rockauto also list incorrectly for autoline parts (D2081 82-84 gm), so I think rockauto listed the interchange wrong for most of this companies parts. Sent from my iPhone using Tapatalk Pro

Do the 88 mj still have a ignition start relay? I remember some fusible links in that area of the 84-86 XJ. If it does have that relay it also a spot it could be jumped and force the starter to engage. I’d try to test if it is working at the ignition switch and find out if the NSS is working or not. Since it’s melted in the ignition switch area it could still be the problem. Sent from my iPhone using Tapatalk Pro

Well crap, I going to be doing the ax5 to ax15 swap, I’ve been buying up pieces for years, one of the parts I got was a bracket to make the ax5 crossmember work with the ax-15. Is that going to make the clearance close to hitting the transmission tunnel in a XJ? Are the heavy duty crossmembers worth anything or are they all wrong for the ax-15 swap any way? (This is the part # I found: Rugged Ridge 12035.6. ) Sent from my iPhone using Tapatalk Pro

A1 Cardon part # 301630 & ac delco 88864745 are the correct one, maybe be other 2.8 vacuum advance will work are well. don’t know why rock auto doesn’t show it for the 1986 Comanche, it does come up for 1985 jeep 2.8. That autoline d2100 looks perfect except for the description it should be what you have already Sent from my iPhone using Tapatalk Pro

Ok that is the correct looking distributor however the part description is for without vacuum advance or centrifugal advance. Big thing to look for is sourcing a new distributor is the wire and plug that go from the distributor to the ignition coil, I needed to find a new one because the previous owner butchered the wiring, Had to buy a used distributor to get that wire and plug in one piece. All the rebuilt ones didn’t some with it and the only replacements I could find were for the electronic advance like you have now. Sent from my iPhone using Tapatalk Pro

That the link I saw on my phone as well. Thought it was tapatalk since a number of links tend to lead to that site. Sent from my iPhone using Tapatalk Pro

It’s pretty simple. The instructions are on line if you look for it. Not much to them as I remember. Far as tuning it except for idle speed there’s not much to do, I’d leave the mixture alone. It’s a damn good carb out of the box If you get stuck I can get pictures of how i routed the vacuum line and ran power sources. For tuning Problem you’re going to have is if the distributor is being advanced correctly by the computer, if it works. Vacuum advance would be better in this set up but I never read anything about nor converting a California emission to this kind of carb. How does it run now? I have a guess about why you and the previous owner are saying it’s had to tune. But what it it doing that makes it hard tune? Sent from my iPhone using Tapatalk Pro

May just be crap burning off, heater core leak can look similar but should have distinct smell. At least as I remember it. Sent from my iPhone using Tapatalk Pro

Where did the smoke come from? Radio? Heater controls? My parents had a car the shorted out the radio and started going down the line. Had to have the dash harness replaced. It was all oem stuff too no fancy radio splicing. I think you’ll just have to start pulling and see where it burn out and how bad, if it just radio you might be able to cut n splice that, if it’s deeper in the harness probably be better to replace the dash harness cause even if you fix it you could never trust it. You could have lost the MJ or been injured yourself. I’d look at the fuse box to see if any fuses blew out instead of going Chernobyl. Turn signal has a fuse and little round relay deal you hear click when they are on. Heater has a fuse too but considering the draw especially these old jeeps have on the ac system and heater blower motor I’d double check that wiring before putting power to it. Radio of course has a fuse but in kind of hoping it is isolated to that system. If it is the main harness it’s probably a melted mess. Although the way power is run to the heater control and fan it is some what separate but even then it’s all in proximity to each other if it got hot enough. BTW it would be a good idea to check the headlight switch plug too, those like to meltdown as well. Some of this reminds me of the leaks my 85 has had with the windshield since I got it every windshield would eventually leak, I think it’s part of the reason the original odometer bit the dust. Never had anything thing like this though, even with years of a leaking master cylinder on the fuse box (thanks PO). Does somebody know what would happen if water got into the ducts and shorted out the blower motor resistors? Could it cause anything like this? Btw if it is the windshield, still a if at this point, when they replace the windshield have then leave the trim off, or find a tool to DIY the trim, some people put a bead clear silicone around the outer edges of the windshield to keep the rain out. Dunno if this is recommended anymore but I’m going to try it on the 85 . Sent from my iPhone using Tapatalk Pro

I’ve had the windshield leak that it looked primarily like it was pooling on the passenger side, eventually I figured out it was the windshield after re-sealing everything on the engine bay side (evaporator & heater lines, foam insulation, blower motor.) I was surprised the caulking in the cowl area seemed ok. Been dry in that jeep ever since the new windshield. Unfortunately my 85 XJ is leaking last time safelite used that crappy windshield glue sold at Vato Zone, wish I complained about when I first noticed he did that, worst windshield replacement ever. It was a early morning repair and I too busy watch the job, guess he didn’t want to heat up the industrial strength stuff they normally use. Sent from my iPhone using Tapatalk Pro

Oh, check the fuses in the box by the battery, huge 60 amp(90?) fuse is for the alternator, if it pops the fuse for some reason you’ve got not alternator charging. Ours did this when Firestone messed up the battery cables one of the times we had them try to fix the loose steering. I cleaned up the cable connections, one of which was a aftermarket generic style where the battery cables leads are clamped together on the positive side. Once it was squared away it didn’t blow the big fuse any more. Sent from my iPhone using Tapatalk Pro

Oh its a 91 MJ? That’s a different, it’s a Japanese alternator with the voltage controlled through the pcm. Still could be a bad ground or battery cables, fuse box/fuse, possibly cluster. Still I’d start by verifying the voltage, might just be the alternator, but when it fails there should be a check engine light or maintenance maybe. As I remember it the 91 has two lights, one is the emissions (o2 sensor I think), the other when a code is triggered. When the alternator started to fail that Check engine light did trigger. The 02 sensor/emissions light was some proprietary chrystler crap so the light could only be rest at the jeep dealer, most long term owners annoyed by it pull the bulb to it. I missed where it was a 91, most of what I said about the gm alternator doesn’t apply. 500k mikes guess you can write to jeep to get a high milage club license plate bracket, if they still do that program. Sent from my iPhone using Tapatalk Pro

For the alternator voltage I had the plug on the gm style alternator be faulty, wiggled the plug and the alternator would suddenly start charging . Since swapping out my 1985 harness the alternator works all the time. I think the renix jeeps still uses the gm style with built in regulator, if so the plug may be bad. But with the other symptoms I’d check the voltage with a tester then start working backwards to the cause, bad ground, c101, fuse box, alternator, something along those lines. Sent from my iPhone using Tapatalk Pro

Ah, yes. The 4.5 was a popular swap for the 4.1 I think it was. The 4.1 was a big POS. I didn’t realize those v8 had the same bolt pattern as the amc & Chevy 2.8 Sent from my iPhone using Tapatalk Pro

I thought the distributor cap had a #1 designated, I couldn’t see anything marked. I think when I replaced the distributor before #1 was right by the screw on the left side of the cap, but your right that distributor can be set to cylinder 1 just about anyway you’d want. Which caddy v8 was that ? I was reading about 2.8 upgrades, one of them is the heads from a 3400 or 3500 engine, but it’s easier to use the whole engine. The 3500 block I saw pictures of look very close to the 2.8, including placement of engine mounts and the place for the distributor. Haven’t found a good write up on it but it’s been done successfully. Sent from my iPhone using Tapatalk Pro

Well it’s not like the timing chain moved, the pistons and valves are opening as they used to. The engine shouldn’t be in danger of self destructing from the valves and pistons intersecting. Its just the ignition timing is off, so the spark is mistimed. I thought the 2.8 to 3.4 were non interference engines, but now I’m not so sure why I thought they weren’t. Sent from my iPhone using Tapatalk Pro

Um when you feel the compression keep turning until it gets to the top of that stroke, eyeball it or use something in the spark plug hole to show when the piston reaches the top. Once at TDC is set check where the distributor is at, if it’s in line with one of the post in the distributor cap just adjust it slightly to approximate 10 BTC and with that as the new #1 go from there. Basically you need to see where the distributor is at when the engine is at TDC and decide what the next best step is. Its more complicated writing it out than it is doing the job. Sent from my iPhone using Tapatalk Pro

Those marks are about where the rotor lines up. Again if yellow is TDC white is about 10 BTC. I’d get to TDC, don’t turn it backwards cause with no markings there is no telling where you’ll be. Once you set at the very top of the #1 cylinder compression stroke you’ll be able to time the rest of the engine off that. Once you’re at TDC see where the rotor lines up with the distributor cap, if it’s dead on a post you can adjust the rest of the cylinders in firing order from there with that spot being the new #1. Then loosen and adjust it just enough so the housing is approximately 10 degrees off from where it was at the TDC. The distributor rotor turns clockwise so a nudge counter clock wise. If you current setting is way the hell off you’ll have to pull it and practice resetting it, as I said the gears meshing like move the rotor during instillation so it a trick to get it perfect. For instillation these kind of distributors can be indexed from just about anywhere as long as #1 is designated with the rest of the spark plug wires following in firing order. It can be confusing as hell but Welcome to 1980s engine management! Sent from my iPhone using Tapatalk Pro

Ok. Have you got TDC now? If so loosen the cap to take a look where it thinks cylinder 1 is. Depending on where it is you can just line up the rest of the spark plug wires with that place as one now. If that’s lined up perfectly then setting 10 BTC is the real trick because as the distributor gears mesh it turns as well, I try to turn the position the distributor rotor face enough to offset it so when it turns as it’s installed it close to correct. Here is a (sort of bad) example of where to set the timing, imagine if yellow mark is TDC white is about 10 BTC. I can try to find a better example or maybe somebody here can explain this better than I can. See if this works for you, if you have TDC you ought to be pretty close. Sent from my iPhone using Tapatalk Pro

It’s not going to say TDC it’ll say BTC because these engines are timed before TDC. Usually these old engines either are timed ATC (after top center) or BTC (before top center), more modern use TDC and the computer moves the timing around. You looking for something that says “ignition timing” it’ll have the rpm + or - and the degrees BTC + or -. I think the standard was 12 to 13 on automatic 2.8 but don’t know for sure. Sent from my iPhone using Tapatalk Pro

Good points carnuck Do you remember where #1 on the distributor was? I thought it was at one of the minting points for the dis cap. I’m looking at my spare distributors they can be set just about anyway you can imagine, like most old school distributors. More modern distributors have on or two ways they can be installed. What I’d like to do is set my new engine i’m building to the timing needed here to get a picture to demonstrate where the distributor would be positioned. It’s the only way I can think of to setup it near correct long distance. Far as the 3.4 goes it’s just a bored out 3.1/2.8 Camshafts interchange efi/tbi engines 1985-1995 Crankshafts interchange 1987-88 until 1995 for the 3.4 & 2005 with the 3500 FWD motors Hell I heard you can drop a Malibu 3500 engine in a s10 2.8 engine bay, the block still has the place for the distributor. Engine mounts probably need to be fabricated. Sent from my iPhone using Tapatalk Pro