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Hi again guys. I'd like some guidance on tackling a No-Start Issue that reared its ugly head again recently. My truck has had this issue since purchasing it from the previous owner in 2021. Thought that I had resolved the problem but it slowly resurfaced. 1986 2.5L MJ 5-Speed Manual Most notable symptoms that occurred BEFORE it began: • Driving: Sputtering during acceleration, and also when shifting upward • At Idle: sputtering when applying gas, and acted like it wanted to die when letting off • At idle: sometimes RPMs increased to, and sustained 2.5K - 3K for a few seconds (after working throttle for a while) Symptoms NOW: • NO Engine Starting (at all) Improvements that I've done up to this point (all within 2 years) Clean/Rebuilt Throttle Body - New Spark Plugs, Wires & Cap - New Vacuum Lines - Cleaned all or most Electrical Connectors - Reinforced & Cleaned All Grounds - New Oxygen Sensor - Transmission Professionally Rebuilt - Installed REM Clock My Evap Canister has been disconnected for several years - and all associated lines have been plugged. But please note that it never reeks of gas, and performance seems unaffected.

Good evening, Amateur here, I just replaced my head gasket, head bolts, exhaust/intake gasket. I am all buttoned back up but having issues getting the truck to start. I have been able to turn it over. But other than that. Nothing else. I know I removed the distributor and got it cleaned up and put back, made sure spark plugs and wires were cleaned. I've done all I can with what I know. Any assistance is greatly appreciated.. This is my DD and starting back work on Tuesday. Thank you again! Respectfully, Jeep88Comanche I6 4.0 4wd

I'm having a weird CPS issue that I'm hoping something else has run into before. A couple months ago the original CPS wiring became so brittle that it broke off at the sensor. I thought "No big deal, I'll just replace it." Put a new sensor on and initially everything worked perfectly. A couple days later I go to use the truck and nothing, spin no start. REMII reading 0 rpm while cranking. Tested resistance and while it seemed good I figured maybe I just had a poor quality new sensor. Looked online and found a different brand high altitude CPS. When it showed up, after replacing the battery (someone may have left the lights on, one of life's little mystery's) installed the new sensor and again runs great. Take it for a drive and it runs like a scalded dog. A couple days later, spin no start again. REMII reading 0 rpm while cranking. Good voltage at battery, no voltage drop along cables, good grounds. Checked that I didn't have pins pushed back or spread in connector. Tested AC voltage coming from sensor, right where it should be. Tested voltage on harness side, and after that it miraculously cranks right up and runs without any issues. Next day spin no start until I test voltage and then it fires up. I'm perplexed to say the least. I was thinking maybe an issue in the ecu so I have one coming but I'm all ears if someone has any other ideas

Ok folks, here's the problem. We've got a 1986 2wd Comanche with a rebuilt 2.5L V4 and a 5 speed manual. We have replaced just about everything you can replace on this thing and it will start (turn over and crank) but will not run. The problem seems to be electrical/fuel delivery related but we're not sure. New fuel pump, new fuel tank and everything else. With a noid light attached to the TBI connector when you go to crank the engine the light on the noid gets bright for a moment then goes dim. We were told that once the engine cranks the niod light should flash. It's doesn't. It just goes dim and we have no fuel pressure in the TBI. The ECM has been replaced along with every other electrical component associated with the fuel delivery system, when we bypass the fuel pump relay we get good fuel pressure but when we plug the relay back in - nothing. We've replaced the relay three times and still the same issue. What I need to know is if this is a wiring harness problem or a ground problem. Any additional info you might need please ask but we're not sure where to go from here. Any "actual" help would be greatly appreciated!

I recently came into a 1989 Comanche 4.0L 5 speed manual 4x4 (Pioneer trim). It's rusty, lifted at least 6 inches on 31s, and doesn't run. I could get it to crank over with a battery jump starter, but of course with the dead battery, that cranks slow; however, it wasn't getting fuel. I replaced the fuel pump and tried cranking it over, but again, really slow, and low enough voltage I felt like the starter was using all the power (therefore fuel pump couldn't pump). So I decided to grab my 2000 Cherokee and use jumper cables, but after hooking it up, the Comanche still showed low voltage on the dash, and cranked over even slower than before. I used my multimeter and checked to make sure the cables were actually transferring power from the XJ to the MJ (under the hood of the XJ is extremely muddy), and everything checked out. I still cleaned the connections anyways, but nothing helped. It was basically just clicking like it had a dead battery. So next I took the battery out of my XJ and put it into the MJ and it just clicked like the battery was dead. Multimeter showed 12.7V at the battery, but the MJ dash showed 9V. I tried cleaning connections again, but still just a click like dead battery. When I put the battery back in the XJ, it fired right up like normal, no slow cranking, so I know it wasn't the battery. So now I'm at a loss. A couple things maybe worth noting: 1) When cranking slowly with the battery jump starter, the battery cables would get really hot, like it had to draw a lot of current to slowly crank. 2) A lot of the dash is taken apart as the previous owner said he planned on chopping the whole front off and replacing everything from the doors forward with a 99 XJ (which I will not be doing). The cluster is still plugged in and seems to be working correctly. Any direction would be appreciated. My first thought is that maybe the starter motor is bad, so it's taking a lot of power but cranking slowly. But before I start throwing money at a project I'm just gonna beat up off road (it's way too rusty to restore and only cost me $250), I'd like to see if anyone here has had the same issue.

I have a 1989 comanche eliminator. Inline 6, 4x4, AX15, 3 inch lift. Been driving fine. Just bought it a couple weeks ago. Has a bit of high idle. Leaks here and there. Smallest amount of coolant in oil but it does have 268k miles. Gonna do the head gasket and such soon. I drove it and parked it, no problem. Blinkers stopped working but was going to look in to that. Been following Cruiser54's tips for sprucing up grounds, adding some, etc. Will keep doing them as i go. The next morning after i parked it in my swamp of a driveway, it wouldnt start. Normally i turn the key and the pump primes, its loud. I can hear it while driving but it seemed fine. Definitely noticeable. This time, no prime. So being before work i didnt do much besides bang on the tank and switch the relays around, nothing. After work, i checked ballist resistor, 1.1 ohms, bypassed anyways to no avail. The relay was swapped around with all the rest so that rules out the relay. I checked for power at pump, i get 6 volts off of the plug for pump with key in on position. I'm thinking that's kinda low. I also get 6 volts if i hook up the wire (bypassed ballist resistor) to my meter and ground it on body. So I'm sure its getting to the pump but maybe not enough? I also did Cruiser54's tip of adding a independent ground on the pumps harness just to be sure as well as clean ground behind taillight housing. I have power on pin 30 of relay and switched ignition power on pin i believe 85 (trying to remember what pins are what). I tried jumping power to the pump and that didn't work. I also removed the pump (before i added the extra ground point to it) and hooked it to the battery for a split second, and it did run. So I'm positive the pump itself is okay. Right now I'm working on tracing wires and connections and sprucing up plugs, etc. I tried looking around other forums, etc for ideas but I'm not sure at this point. Any ideas or thoughts would be greatly appreciated.

88 Comanche 4.0 jus died and won’t start.verified spark and fuel.swapped computer.before I swapped computer I leaned on the brake pedal and heard a clicking sound.ended up being the fan clutch.what the hell? changed computer,still no fire.fan clutch still engages when I push brake.unkooked computer completely and brake still engages ac fan clutch. please help

So for a few weeks my MJ has been randomly stalling. Be driving, and engine will die. Sometimes it'll restart, but usually I have to let it set. MJ would drive awesome, except when it would stall. I thought it was fuel delivery. Cause, after the engine would stop, if I put gas down the TB, it would start. Well, finally it stopped and would not start. After checking the usual, I was kinda stuck. I decided to take a look at the Distributor. I had installed it a few months back, new from AutoZone. As looking inside, I found my problem. The "pulse ring" is pressed on to the shaft. It is NOT supposed to rotate independently of the shaft. On my New Autozone Distributor, that pulse ring is loose. It rotates a few degrees on the shaft, just enough to mess up the timing. I was able to force it on the the shaft to lock it. It's advanced the timing now, I think. I need to put a timing light and see. It will come loose again, I need to find a way to actually lock it. like a tac weld. If it advances the timing, like the CPS mod, I may keep it. Anyone else see this issue before?

Well yesterday the MJ decided it really liked it at the Grocery store. Luckily my brother and his family were eating pizza at the pizza joint next door. It all started when The MJ died on me as I was pulling out of the feed store and it died when i came to a stop to pull out and then it did one of those long cranking episodes. It smelled like gas and it would hit and want to start but acted like it just couldnt catch up. I cranked and cranked and it finally fired up. i drove it to Emily's work and shut it off. Emily came out side i started it no prob. We drove to grocery store and shut it off. Emily went in to the store did some shoppiing and then came out to the truck, it started up no prob. We pulled up to the stop sign and it dies and I crank and crank and then we push it back to a parking spot were i crank on it until the battery starts to fade. I am about to give up and it starts. I pull back up to the stop sign feathering the gas ever so slightly and the SOB dies again. The battery is done at this point I surrender and go eat some pizza. Basically it seems as if it is flooding randomly? sigh We have been driving it for five days with out much problem besides the heater controls not working and I thought I noticed the ac pump kicking on although it was not set to a/c? Someone mentioned fuel return line maybe leaky or clogged?? Things I have replaced: injectors, FPR, ECM, spark plugs, cap and rotor, spark plug wires, fuel filter, IACV and CPS. For details on the truck see my project thread. Any help to get it going so I don't have to trailer it home would be greatly appreciated. Thank you!

Hey everybody. Its been a while since I've been here, mostly because all is well in Jeep land. Well not anymore. My 89Xj will not run. The 90Mj will and I have been parts swapping to trouble shoot. The Xj is a 4.0 auto np242 3.73, power everything. In short its a Waggoneer. Currently the Xj has good spark, OK compression, and fuel, including injector pulse. The timing has been set and reset a bunch. I've been battling this for about a month or so. I'm at my wits end. I've done so much searching that I can guarantee it is not an evident issue. The story though is pretty short, so I've had the xj for 8 yrs. Most reliable rig I own. This past summer I caught the illusive Mj locally. So I did the stupidest thing. Made the Mj run with parts from the Xj. Fast forward to now. No combination of anything fixes anything. Any advice will be taken. Specific questions will be thoroughly answered. Thanks in advanced.