TeKdo

are those holes on the right threaded for an NPT hose barb or does that rubber block thing just plug into there?

Will look into doing that, I've been getting a little sketched out about that thing anyways. Haven't replaced it yet though, I didn't know you could replace it with just vac lines.

Well it dropped the RPM about another 50 to 100rpm...getting closer! I wonder if theres a couple other random vacuum caps or lines that I've missed now.

Oh my gosh i completely missed that. If its that simple I'm gonna be a little upset with myself.

Thanks, I'll take a look into your thread. As far as for why this guy was parked, it was because the pinion bearing on the Dana 35 took a dump and the AX5 had expired as well. Plus my grandpa wanted to send it to a shop to get it fully restored at one point after he got T-Boned. As far as I know the ISA is the factory AMC one, he never used aftermarket parts when replacing something on this truck. I also don't think that the ISA has been really messed with honestly, it looks like the factory adjustment, but it looks wound all the way in already too. This is what the ISA looks like right now. Also thanks for the tip on the ISA. I thought it worked a little similar an IAC which is why I unplugged it to see if the idle would come down if the ECU wasn't telling it to open lol. Since the ISA is just for startup it works perfectly as well.

Hi guys, sorry to beat a dead horse but I really can't find any more tips on how to bring the idle down on the old girl. She's an '86 2.5 with an AX5 and idles right around 1300rpm. It idles just fine when its cold but as soon as it gets to operating temp (right around 200 *F on the gauge cluster) the idle bumps up to 1300rpm. It used to idle up at 1500rpm until i changed the coolant temp sensor (the one that goes to the ecu) and it dropped to 1300. So far I've -Fixed Vacuum Leaks -Tightened the manifold bolts -Replaced Coolant Temp Sensor (to ecu) -Done the Cruiser54 Ground Refresh (No Jeep Cables Kit though) -Checked TPS harness -Fiddled a bit with the TPS according to Cruiser's tips to see if the idle would drop after adjustment I've also tired to block off the vacuum port on the EGR valve to see if that was leaking since its new, that didn't change anything I've tried unplugging the Idle Speed Motor that pushes on the throttle to increase idle to see if that would bring the idle down (it didn't) Finally I've tried to adjust the TPS according to Cruiser's tips but I can't get a good back probe onto the senor's pigtail on my 2.5...there's fuel lines and a heater in the way. Pictures If it's worth noting, it still gets like 25 to 27 mpg with the high idle which really confuses me. I also don't have a working factory tach installed because it died years ago so I'm measuring the rpm with a new Equus 6088 that I picked up from O'reilly just so see if my ears were playing tricks on me so maybe the tach is out of wack or not accurate? Either way, I've run out of things that I could think of to replace outside of the TPS and possibly an O2 sensor and Idle Speed Motor. Both of those guys look a little worse for wear and I think my grandpa gave me a spare O2 sensor along with the truck too. I am worried about adjusting the TPS properly since i can't get my multimeter probes in there good. Dunno where I'd find a new Idle Speed Motor either...kinda wishing i had single barrel carb now or some kind of renix diag tool to see if a sensor is out of wack. Thanks for reading my little rant and any help is appreciated.

I'm not gonna sweat it, idle is normal and its not burning oil like you'd expect from wasted rings and all the vacuum accessories work as designed.

That's what i meant by "cold" lol. I've seen a decent amount of guys on here in Canada and other colder states so I was wondering if something was just up with my Jeep because 30F doesn't seem cold at all. I just replaced the thermostat when the cold came and even blocked off half the rad with cardboard to try and keep it warm. I've been suspecting the coolant temp sensor though because when it's below 50 outside you gotta give it a bit of pedal for it to idle. I have had it at highway speeds for longer periods of time (before i blew up the old AX5...don't ask about it, it's a long story) and it did clean up pretty good. For the first couple weeks that I was driving it after getting it running (it had been sitting since 2006 and I've been driving it daily since the beginning of December '23) it was gutless. I expected it to be gutless because it was a 2.5 but man, having to downshift to 2nd to climb a mild hill was kinda infuriating. It did clear up and come back around (dunno if there was a sticky ring or just carbon buildup) but between the fresh ignition system, fresh charging system, updated grounds, and a tps adjustment along with all the snake oil I've thrown into it (Berrymans in the gas, Seafom in the oil before an oil change, and Marvel Mystery Oil) it came back around and has some guts now. Maybe it just needs more time to burn off the junk from sitting? Wow, I wouldn't expect that amount of crankcase pressure to be normal lol

Update: Dieseling is mostly gone. I did a check before the post of for if the connectors on the ignition switch were garb or starting to go out and nothing seemed wrong. Unplugged it and plugged it back in and its almost all gone. No longer diesels for a couple seconds, now it just diesels for a tick after going to key off, like one or two little combustion cycles after everything goes dead. Starting to think the little 2.5 is a little tired but i don't think that its something to lose sleep over. Crankcase pressure seems a little high to me (when you take the oil filler cap off, there is a ton of air flowing out of the top). Not sure if that's normal for a Jeep, but with the little import cars I normally work on that's a little worrying. She doesn't burn oil...the intake tracks look clean looking thru the TBI, and the plugs and fuel system are fresh. I put new plugs, wires, coil, and fuel filter in it when I got the truck a couple months ago. The old fuel filter was super clean too, no dirty gas came out of it when i pulled it down and plugs looked clean minus one that looked super gross due to an old plug wire completely disintegrating. As for the bad gas...I'm not 100% sure if that could be a problem. The first tank that I ran through this truck was a can of Berrymans and about 10 gallons of California 91 Octane Shell V-Power. Now, I run the truck in Washington State on regular 87 Octane from Arco, same as my grandpa did for the 30 years he had the truck. It didn't really diesel up until recently after we had some cold weather (Not super cold, like in the mid 30s Fahrenheit) and a little bit of snow. I did a good bit of driving in that weather between shuffling around town for work and a couple snowy rescues (Maybe a max of 2 weeks operating in that weather.) With my other cars (Mid 90s FI Japanese Hondas and Mazdas) they didn't really have issues running for a week or two in this kind of weather outside of cold starts because their batteries are smol and kinda weak. Is the Renix system that different that it can't cope with that kind of operation or if I'm just using the truck wrong? Other than that, Thanks everyone for the help!

I'm pretty sure that it isn't ignition switch, every single ignition switched power source goes dead when the key is turned off. Now that you mention it, i am a little suspect of the injector. But the spray pattern is good and it doesnt glug fuel ever. The reason I'm suspect of the starter relay is because thats the only spot where there's power when i go to key off. Looking at the fsm, I think that the contact for the starter relay that gives power to parts of the truck sticks ocasionally and lets the alternator give power for a couple seconds to let the injector pulse a few times before unsticking and shutting off.

Nope, I tightened them pretty recently, like 1 or 2 weeks ago. Sprayed some starting fluid near the flange to double check and make sure I had a good seal, part of my vacuum leak hunting i did.

Hello Everyone. I have a 1986 Comanche X with a 2.5 and an AX5 that I daily drive. I've done Cruiser's tips 1 thru 8 as well as fixing any vacuum leaks that I come across. The only "mods" I've done are an H4 conversion and added fog lights (both of which are on their own isolated circuit from the factory wirin straight to battery, own custom fuse and relay block.) Recently it has started to diesel when i turn it off intermittently. Each time this has happened it stops and dies after a second or two and floods the engine. I was wondering if anyone else has had this happen and if I'm on the right path for repair. I'm suspecting that the starter relay is starting to fail and stick open sometimes letting the alternator keep supplying power after the key is off. I've been thinking about taking the whole charging system off of that circuit to replace it with a megafuse to have the lasternator go straight to the battery and then have the batter feed by itself to the starter relay. Should I do this or just replace the starter relay?

Sweet, that's actually great to hear. The fronts do stay on when the hazards are on and brakes applied. I just thought I was going crazy since the turn signals flashed while on the brakes.

Hello Everyone, Looking for some advice regarding the hazard lights on my '86. They work just fine...except for when you're on the brakes. Whenever you're on the brakes the lights just stay solid on the dash, and it's only the hazards that do this. The turn signals work just fine when you're on the brakes. I've cleaned all of the grounds that I know of (At the tail light, the battery ones, and the one underneath the airbox), I've changed all of the bulbs (NAPA 2057s in the back for all 4 and Sylvania 2057NA for the front) and cleaned out all of the old crusty bulb grease that was in there, I added a new engine ground (from the dipstick stud to the firewall), and I've swapped in new relays and swapped the flashers with each other (Novita 552s and Tridon EL12s). I do have the flasher's mismatched right now because I only had one old Tridon EL12 kicking around and got a bad Novita 552 from Carquest and haven't gotten the chance to see if matching flashers would fix the problem...but looking at the wiring I think that they're on separate circuits. I've also pulled apart the long flat connector at the bottom of the column for a quick clean to see if any of the contacts were too dirty or corroded. I'm really tempted to replace either the turn signal module because sometimes the hazard switch doesn't like to stay pushed in and I know that one of the arms for the self canceling either needs a spring or is completely broken. I'm also tempted to add grounds at each turn signal bulb because every forum post I've run across so far says to just clean the grounds...but all of my grounds are clean and I even brought them down to bare metal to ensure they're grounded well.

1986 Jeep Comanche X AMC 2.5L (150CI) / AX5 / NP207 / Dana 30 Front / Dana 35 Non-C-Clip Rear / Long Wheelbase Build Date: Don't Know, Door sticker is a little worse for wear Current Location: Vancouver, Washington Status: Running-ish. Road Registered and driving after 20 years of sitting but things like to expire Notes: Long Range Gas Tank (~20 Gal According to the Pump) Factory Trac Lok Limited Slip Diff (According to the diff tag and chart) Vinyl Bench Seat Brown Interior Tinted Rear Glass Split Sliding Rear Window Sweet Orange Pinstripe "Navy" Blue? (It's darker than the other blue ones I've seen and that's what grandpa said the color was) The Vacuum CAD still works really good somehow Mods: H6054 to H4 Conversion with Accompanying Relay Addition (No more hot headlight switch) Eye Melter 9000 Bulbs (Hella 90/130w Bulbs) Old Napa Fog Lights Current Owner: Me. I actually attempt to drive this truck as my daily whenever it works. Last couple times I've taken it out it didn't go so hot though. Blew the original AX5 and swapped in another one that I rebuilt out of a TJ...and right after that the Clutch Master Exploded because of course that's the one thing I didn't change when I did the trans. But, still love the truck and I love how it looks. This truck was originally my grandfather's. It's the first vehicle he ever purchased new. Originally bought somewhere in northern California (Either Sacramento, Stockton, or Redding) in '86 when grandpa wanted a little 4 cylinder truck to haul full size wood sheets from the store back to his house for projects. He daily drove this truck until the late 90's when he was T-Boned by a lady. Truck was down for a couple years and re-registered in '00 as a salvaged vehicle. The truck then got passed around as a little mule for whoever needed it in the family until it was parked in '07 or '08 because my uncle slammed the thing into 4L going down the freeway (probably why the stock AX5 grenaded on me all those years later). After that I know it got an NP207 from a junkyard which was rebuilt and stuck back into the truck. After that grandpa did a couple small jobs on the truck because it never ran quite right after the whole 4L incident. He threw a new fuel pump in, redid all of the emissions equipment (Needed in California for Registration) and then just stopped working on the truck all together until I started working on it in 2022. I got the truck running again after all this time and brought it up to Washington with me so that it could be my mule. I love this truck and I remember playing in it and it's old camper as a kid for the longest time (abandoned the camper in California with my uncle because it was FUBAR, too much damaged fiberglass and a broke lock...plus I didn't really like how it looked on the truck and the trasporter wouldn't transport it to Washington with the rear glass flapping in the wind). Looking forward to slowly bringing this thing back a little nicer than before but, she's never gonna see a full restoration...it's just too good of a little work truck to make completely nice!