89 MJ

If that doesn't fix it, next time it happens, check for spark. It is getting air, so it either must lose fuel or spark.

If I recall correctly, the Bosch O2 sensors are the ones that are sometimes ok, all of the others are no good. You can also use a wideband O2 sensor and the REM to control open loop and closed loop.

I think that anyone concerned by the color of a vehicle called the Comanche isn't going to know what a Jeep Comanche is. I think you've got a far better chance of someone yelling at you that your vehicle burns gas and is therefore bad for the environment. And that more than likely won't happen either.

Vacuum should drop as throttle is increased. At WOT, you should have 0 vacuum If the engine was at operating temperature, I think you're problems are a combination of a vacuum leak somewhere and a bad O2 sensor.

Correct. Maybe cycle it 2 or three times. Just to make sure you’ve got fuel at the injectors.

What happens if you cycle the key to prime the fuel system a few times immediately after it does some of its bucking? I wonder if your fuel pump is on its way out.

You can also use a smoke machine to help find vacuum leaks.

Your REM should've come with a printout with information on ranges for all of those parameters. VAC is manifold vacuum, so that number will depend on how much you're stepping on the throttle. You should be closer to 15" Hg at idle though. RPM seems normal, maybe a little low. For vO2, reading less than 2.5V, your engine is running rich. For greater than 2.5V, it is running lean. This is normal if the engine wasn't up to temperature yet. EX RICH agrees with vO2 LP open means the engine is in open loop, which means its running rich. TPS should be reading 17% when closed, so you need to adjust that. IGN is your ignition timing. 12-13 seems perfect for base timing. LT is long term fuel trim. Reading less than 128 means the ECU is commanding less fuel on average than base to run. If its reading 128, its using the base fuel curve. Greater than 128 means the ECU is calling for more fuel than base. All that data taken from @NickInTimeFilms website: https://nickintimedesign.com/rem-gauge-readouts/

Great find!

That looks excellent!

It absolutely is. It was only found on the early years though.

I think these AMC I6s must just have a tendency to have quite a bit of blowby. My MJ engine has less than 150k on it and has blowby, my Eagle engine has an estimated 80k on it and has some blowby, and the previous engine in my Eagle had 110k on it and tons of blow by. Oddly enough, the first two I said have good compression and neither have any oil consumption issues.

Its pretty easy to drop the column down a little bit. I don't have a tilt column, so it isn't too bad, but its still scary. I just figure that when I break it, its an excuse to get the brushed silver one

I ran the cable for mine across the firewall and then inside the cab near the brake booster and fuse block area if I remember correctly. You don’t necessarily need it inside the cab with though. It might be nice to have it so you can walk around the engine compartment with it in your hand.

I see. It really is a tough decision to make.

But would you want to swap it back and forth twice a year? I know I wouldn’t, but that could be just me. I also worry that you’d lose some of the usefulness of it being a truck. Street tires might struggle making it up your hill, you’ll have to be more careful going in and out of driveways, that sort of stuff. Another truck wouldn’t exactly fix those problems though either, other than keeping this one a little easier to use. I think a turbo 4cyl MJ would be sweet with these parts on it.

That’s a steal

Any updates on the truck?

May 2025 - @Flexj's 88 Sport (Not so) Low n Slow Build Thread- 88 Sport Low n Slow ( I may need to change the build thread name after doing an LS swap and lifting it XD) Year/Model - 88 Comanche (Pioneer?) Drivetrain- 4.8 LS, NV3500 5 speed, Np231J with eBay clocking ring adapted to chevy transmission, Ford 8.8 rear and HP 30 up front. Cooling- 3 core aluminum off brand radiator. Three E fans. Electrical/Ignition- Stock chevy LS coil packs Suspension/Steering- Spring over on the rear, front is 6" Metal cloak progressive rate coils. Netting 8" of lift in the front due to the LS being a bit lighter then the stock 4.0 Interior- Stock interior except for PT cruiser seats and the center console is from a jeep TJ for the cup holder. Brakes- Stock 98 front disk brakes, stock 8.8 rear disc brakes, WJ master and booster. Lighting- All bulbs have been replaced with LED bulbs. Exterior- Bushwhacker XJ flat fenders adapted to fit the Comanche bed. Wheel & Tires- 37x10.5R17 Goodyear Wrangler MTs Misc- Warn front bumper, ARB front air locker, dedicated amp for mids, speakers moved from door to kicker panel so I can still listen with the doors off. Best MJ story- I got this from a friend, who bought it from his friend knowing I had been looking for years.. This has been my dream truck since I was 16 and got my first XJ. He sold it to me with zero upcharge, literally asked me to come over and surprised me with it. I have had this truck for over ten years now and I will never get rid of it due to the history and how long I was looking before I managed to get this one. This Jeep showed me my friends were truly good friends that cared to help me out when they had a chance too, not to mention the months of wrenching on it after where I had multiple friends and my brother helping me every day after work! Nothing brings people together like Automotive and home projects! CC is Awesome! Why? Because all this information is a dying breed. I was raised with people like Cruiser54 and Hornbrod on CherokeeForum, if it wasn't for them my Jeeping days may have been much shorter lived. Now I have a 23 year old nephew rebuilding a ZJ and have learned we need to keep this information alive for future Jeepers and the only way to do it is by archiving all the information here where it won't disappear forever. The truck turned out great, @Flexj! Congrats on MJOTM

I see what you did there

So what are your long term plans with the truck? I ask because lowering it 2" and welding in the bedside patches will probably lead to the tire hitting the bedside when the suspension compresses. You might also need to get a shorter driveshaft then too.

Can you post pictures of both track bar mounts? I wonder if you have a different frame side or axle side mount.

There are some pictures of those thread. And because you have a SWB truck, you can use two passenger side panels because you don’t need the cut out for the fuel door.

Nope. Only because I’m watching it now on the PBS app.

I'll start by saying that the the body looks pretty decent. I'm not sure what's up with the primer though. You should try to get an answer on that. That MJ most definitely has a YJ AX-15, like Tim said. The transfer case is clocked differently and the shifters are not MJ/XJ units. Looks like you might have some front end work to do if you get it. Looks like the tires are cupping pretty bad on the inside edges. I'm also seeing front lift springs and an add a leaf in the rear with a new track bar and sway bar end links, so maybe the suspension issues are already fixed. I'm also very curious as to what is up with the spots I have arrows pointed to. The one pointed to the floor looks like a poor repair, but its hard to say. Those plates on both sides should not be there. Definitely check to see if rust is under there. I'm also seeing another spot right at the top of the picture along the "frame". I'm also curious as to why the passenger side floor is silver when nothing else is. With all of that said, if it is a running and driving rig without rust or very minimal rust, I would say its a fair deal. Not a great deal, but a fair one.