trailturd

So I wanted to give an update on this. Even though I had replaced the ISA recently, I narrowed it down to that with a continuity test on the stepper motor itself. Replaced it with a Crown brand this time and so far it's been working as intended.

Bought a new relay and tried it, as well as swapping the relay from the fuel pump, which I know is good. Started jeep and idle instantly went to 3000 and climbing before I could shut it off. Looked at the ISA and now it looks fully extended. Bottomed out the adjuster on the ISA and the idle is still high on start up, 1200-1500 and starts to climb as it warms up. ISA still does nothing after shutting off motor and taking key out. I'm at a loss here, not sure what else to check.

So I sprayed carb cleaner all around the intake, throttle body, and vacuum lines while running and zero change in RPM. Cleaned and checked ground, no change. Now that it's gotten colder here, low 20's, high in the 50's it has not had the random high idle with the stepper motor plugged in. If anything the plunger has retracted and I was having to keep my foot on the gas to keep it from dying at stop lights. Once I had the motor warm, I adjusted the ISA to 800 rpm and it's been fine once the motor is warm. The ISA is still not opening on key off, or adjusting for cold idle. I still have to give it gas to start every time, and at stop lights until the engine is warm. What am I missing? Is there a intake air temp sensor on the manifold that could contribute to this if it's faulty? What other sensors should I be looking at that would effect the ISA moving?

I’ll spray for leaks and double check/clean ground just to rule those out, but to be honest I don’t have high expectations.

Even new the isa never opened the butterfly after turning off the key. When the idle isn’t crazy high it will idle around 800 rpm so I believe I have it adjusted right.

Except that the isa is new, and I’m having the same problems

87 Comanche 2.5, I'm having a idle issue and I'm having a hard time diagnosing the problem. The issue I'm having is that the idle stepper motor works intermittently. Originally, it wouldn't start without pressing on the gas pedal. Once warm it idled fine, but when cold the idle was low. Then I started to have issues with having to step on the pedal to start it and once started, sometimes it would be fine, other times it would rev to 2500-3000 instantly and not idle back down. I checked to see if the stepper motor was opening the butterfly at shut off and it was not. Figured the stepper motor was bad, replace it, and the TPS at the same time. Set the TPS with a multimeter per the instructions found here. https://cruiser54.com/?p=54 That didn't change anything, still had the random high idle and having to give it gas to start. After having it high idle every time I drove it for about a week. One day I went to drive it and the idle was back to normal, so I unplugged the stepper motor so that it couldn't change the idle, and that was fine, I just had to give it gas on start ups. Which was way better than it always trying to rev to the moon. Poking around under the hood to see if there was a sensor or something that would be messing up the information that the computer sees, I noticed that the temp sensor on the manifold just below the TPS had frayed and exposed wires. Hopeful that this was my problem, I replaced that sensor and still zero change. I'm at a loss. What signals the stepper motor to increase or decrease the rpm? I know it's from the computer, but what signals are the computer looking at? I just don't understand why it never opens the butterfly on shut off, but will randomly decide that the idle rpm needs to be 2500-3000rpm. For now I'm back to just driving with it unplugged and having to give it gas on start up. Other than that, everything else is normal. All ideas welcome, about to sell this thing if I can't figure this out.

Just wanted to give everyone a update. I replaced the track bar with a double shear adjustable one and centered the axle. I replaced the stock lca with adjustable ones with rubber bushings and set them at 16.09”, replaced the steering stabilizer, and I noticed the motor mounts were trashed so replaced those too. Jeep drives great now, just wish I would’ve done all of that right from the start.

The stock control arms

86 MJ 2.5 AX5 converted to 4wd with HP30 from a 96 xj. Added a Rusty's 3" lift when I did the conversion. Has had bad death wobble ever since. Replaced trackbar with a new stock length, since there was some play in the old one. Seemed to make it worse. Aligned with 6 degree caster, not sure if that is enough, considering getting adjustable lower control arms to get the caster in the 7-8* range. As well as eliminate the question of worn out LCA bushings. Running out of things to check and don't want to just throw money at it without having an idea of what's causing it. I got underneath it and had someone cycle the steering, tie rod ends all seemed fine. Steering box is tight to the frame, I swapped that out when I did the 4wd conversion as the stock box was non power steering. Front drive shaft has new u-joints also done during the 4wd swap. Ball joints and wheel bearings all checked out fine. Track bar moves a very small amount at the axle, but it looks and feels like it's just the bushing flexing slightly. What am I missing? I can drive 40-50 down a washboard rough gravel road and it's fine. Get on smooth pavement and hit an expansion joint wrong and all hell breaks loose. Any ideas? I'm at my wits end and about to light this thing on fire

I have an 87 2.5 ax5 non cruise that I 4wd swapped. I'm having the hardest time finding the correct speedometer cable for this thing. Everywhere I look they only have the newer style with the plastic end. I'm looking for the metal end that goes to the speedo and has a metal clip that holds it. I even tried looking up older cherokee cables on rock auto and if the parts pictures are correct they don't offer it. Anyone have a good part number or source?

I recently acquired a 87 comanche that I swapped to 4wd. I noticed that when the motor is running the fuel gauge is pegged past full, but if I turn the key to the 2nd position, just before starting, the gauge seems to read correct. I know that the always full reading points to grounding issues, but what about what I have going on? Planning on doing this procedure outlined below. The official test procedure from the 1988 FSM is: 1. Disconnect C139 -- Needle should go to Full. If the ground to G197 is okay. replace sender. If not ==> 2. Connect C139. Test C203 terminal 15. Reading should be between 0 and 88 ohms. If okay, replace gauge. If not okay, repair open to sender. The simplified version of that is, unplug the 3-wire connector outside the fuel tank. That gives you an open circuit on the sender (infinite resistance). The gauge should read Full with the connector unplugged. If so, jumper the small wire (violet?) to black on the chassis side of the connector (zero resistance). The gauge should swing to empty. If that doesn't work, try jumping the violet directly to the chassis (making certain you get a good ground). On the tank side of that same connector, put an ohmmeter on the violet and black wires. That's the circuit through the sending unit. The reading should be somewhere between zero and 88 ohms. (I don't think the scale is linear, though, so don't assume that a half tank will read exactly 44 ohms.)