dastrius

Alright, good news! Went 45min away to the nearest O'Reilly's that had an ICM and grabbed it. Installed and she fired right up. Not 100% confident the truck won't do the whole gasp for air jig again but at least this is forward progress. Thank you again for the help! If I have any further issues with it I'll reply here. :)

Just checked the coil, no spark coming from it. Checked the yellow wire leading into the ICM, it's getting 11.9 volts (read somewhere it's supposed to be a volt under battery voltage so that checks). Maybe ICM is dead? Leaning towards that or CPS. It's putting out .8v-1v AC which is a bit concerning given it's higher than typical range.

Fuel pump is about 8 months old, but is a bit noisy. Checked fuel pressure and it holds at about 30psi while running. Grounds have all been refreshed and I relocated the fuel pump ground as per Cruiser. Haven't tested any other sensors just yet, wasn't sure where I should start looking. Sounds like ignition coil is next.

Hey all, happy Sunday! Got kind of an odd issue going on with my MJ and need some guidance. About a week ago I stopped at my local glass shop to have them reattach my rearview. As I was leaving, the truck had a real hard time starting. Crank crank crank - nothing. Did this once more and same result. Third time, it made a very odd kind of swallowing sound like it was gasping for air. For preface I have a CAI style cone filter in place given I didn't have a factory airbox at the time of the 4.0 swap. As it gasped for air, a puff of smoke came from out of the air filter. Thought it was odd but given I was on my lunch, I couldn't check it out right then and there. Let it sit for a minute and it turned right back on as normal and drove back to work. I had gotten gas the previous day and chalked it up to being bad gas. Truck was fine for about a week until 2 days ago. For the past month I've been fighting a real bad oil leak coming out of the back of the valve cover. Dripped down into the bell housing and would come off the bottom of that, and coated my whole undercarriage as I'd drive. I work for a Toyota Dealership and asked one of the techs to once over my work and see if he could spot where I was messing up with the valve cover leak. I let the truck run and it just randomly shut off when it got up to temp. Thought that was odd and went to turn it back on. Surprisingly, the motor did the whole 'gasp for air and blow smoke out the air filter' gag again. The tech was flabbergasted. Waited a few minutes and it turned right back on. Couple more minutes, turned right back off and did it again. This time, the tech caught that as it gasped for air, all of the pulleys and crank spun BACKWARDS and then stopped when I stopped cranking. We were stumped. It was getting late so we let it sit for a few and got it to run and limped it home. With the reasonable amount of time I looked at other people's issues on the forums, I figured maybe it'd be the CPS, given also that's the running joke of all renix issues. Measured it as per Cruiser54's guide on testing it, and both hot and cold it reads between .5v and 1v AC. Pulled it and cleaned off the tip thinking maybe it was gunked with oil and clutch material. Turned it on and shut off again once up to temp. It was getting late and I called it a night after redoing my VC gasket for the 5th time this month. (side note: I got it fixed!! 96+ VC with the OE metal grommets and a VC Gasket for a 95 4.0 ftw). This morning I walked out to the truck and tried to crank it over, and now it doesn't want to start at all. Tested CPS once again and is within spec. REM shows no codes at all. I'm stumped at this point, and any help is appreciated! Technical details: 86' MJ with a 4.0 Swap from an 88' XJ with a HO head on the block. Rebuilt about 5k miles ago. Thank you!!

Definitely want to adjust the TPS but I don't think that would give any issues being produced. Do you have a multimeter? Measure the continuity between the wires from the starter relay to the starter, and see if there's any resistance. Could be corroded somewhere that's not visible.

Another option is this harness meant for ATVs from Harbor Freight. I used it in my MJ and it was pretty straightforward. comes with pretty much everything pre-wired, just hook up to power and cut and solder/crimp your connections for your foglights. Got it working with my OE Marchal Fogs. Still need to design and 3D print a bezel for the switch but for now it sits loose in the original fog light switch cutout lol.

Well thank you for the help guys, I appreciate it. Went in there today and did some inspectin'. Turns out that when I was tugging on cables to wiggle the new ECU into it's place, I must've accidentally tugged on the harness going to the back of the gauges. Pulled the gauges today and wasn't even connected. D'oh. Reconnected the harness and worked perfect lol. I guess that should have been my first place to start before digging too far into any other wiring. Thank you again :) -Jared

Hmm odd, I did swap the entire engine harness with the 88’ one but the dash harness is stock to the truck, and it’s October of 85’. It originally had an AMC 2.5 TBI in it before it decided to call it quits. I’d assume a bad ground since I’ve heard of similar issues being caused by a bad ground. I unplugged the headlight harness to attempt to isolate the issue and make sure it wasn’t a bad ground from the turn signal sockets since other forums have pointed that out to be the culprit for similar issues, but still continued to stay lit after unplugging the headlight harness.

Hey all! I’ve got some electrical issues going on and trying to see what insight there is on my issue. I’ve got an 86 MJ that I’ve successfully swapped a rebuilt Renix 4.0 w/ HO Head, and a rebuilt ba10 into (I know, ew). It all runs cherry and have no issues with it up until this point. Now when I did the swap, I used the 88 Engine Harness but kept the 86 Dash harness still in the cab. I’m sure this is where my problem lies but I’m curious to see what others say. When I turn the key to the on position, my turn signal indicators and high beam indicator turn on and stay solidly lit. The illumination lights for the gauges also are slightly on even with the headlight switch pushed in. Along with that, none of my gauges work except for the tach. Funnily enough, all of my exterior markers work perfectly fine. I’ve gone through and checked my major grounds and look to all be properly connected. Side of the block ground, battery ground, dash ground, ground strap on the block, and ground under the air box are all hooked up correctly. Tried cleaning my C101 and had no effect. I also cleaned my C100 Bulkhead while I had it apart. Seems like back feed coming through to my gauges. I’d assume this may be an issue with Jeep moving around the pins on the bulkhead and pins not lining up, but I’m curious to see if anyone has had any issues like this. Thanks in advance! -Jared

86' MJ 2.5L / AX5 / NP207 / D30 / D35 / LWB Unknown Build Date, Build Sticker is missing Current Location: Southern Oregon Status: Put her back on the road in October 2024 after 12 long years of sitting in the woods of Roseburg, Oregon. When I got the truck, it had a headache rack, factory front skidplate, factory tow hooks and a tan bench seat interior. Since, I've removed the headache rack, swapped the doors (all the rods for lock and latches were rusted together and passenger was unable to open), which included a free upgrade to power locks, power windows and the little wing windows. I've also swapped the interior from my 88 XJ (which was rolled) and now it has rocker XJ Seats, and all in the cordovan color. Also replaced the heater with a brand new universal heater from VintageAir. Moving the heater controls allowed me to stuff a double din radio with Apple Carplay into the dash. Day I bought it: Now:

Hey all! I’ve been dailying my 86 LWB for a month now. 2.5 TBI with the 23.5 Gallon Tank. It has 3 straps and comparing to other images online, I’m 100% sure it’s the 23.5 Gallon tank but there’s always room for mistakes. When I go to fill up, it only takes 12 gallons and stops there. I usually fill up somewhere between a quarter and an eighth of a tank. I would assume it being a bigger tank, it would take more gas. I’ve got a brand new pump/sending unit and made sure it was for the correct unit for my sized tank. I’ve also swapped my gauges and it’s done the same thing on both sets. Could it maybe be the sending unit is reading wrong and I’m only using half a tank when it says it’s right above an eighth? Any help is appreciated.

Hey all! Not 100% sure I'm posting this in the right topic, but... When I was putting my dash back in my MJ, I noticed I somehow misplaced my headlight switch retainer. Just bought myself a new 3D Printer and figured I'd try to make one rather than wait weeks for a MJ/XJ to be parted out near me. So here's my attempt at it- Thingiverse Link It's not a direct recreation, but it's what I could find to make it work. Hopefully it helps someone out in the future! Btw, I hadn't seen any info on it in my searches, but the thread for the retainer is 7/16-24 if anyone is after that. :) Thank you! -Jared

Half tempted to try to 3D Print one.

You are absolutely awesome! Thank you! Definitely makes a lot more sense, not having that.

Oh, I hadn't even known there was supposed to be a cone on the end, do you happen to have pic of it at all?