Eagle

Agreed. My '88 XJ is sneaking up on 300,000 miles on the original engine. Bearings are all original and there's no unusual noise, and the oil pressure is the same as it has always been as far back as I can remember. In fact, until I saw this thread I had never heard of unplugging anything to "prime" the engine when changing the oil. And I beat flint's 45 years by a decade.

Are you SURE it's rubbing the inner fender, and not the lower control arm? Because if it's rubbing the lower control arm, not even a 4-inch lift will help. In fact, if it's rubbing the inner fender when turning a lift won't help anyway. A lift only helps if the top of the tire is hitting the flare or sheet metal.

I'm going to guess that the degreasing operation hosed a sensor. I know one of the sensors near the throttle body isn't supposed to get wet. Might be the TPS -- which would affect the transmission.

Toggle switch. Use it in the mud.

Just to be contrarian -- you do NOT have to lift a Comanche to run 31x10.50-15s if you use Jeep rims. Now that you know you don't "need" to lift your truck, how much do you "want" to lift it? Especially since it's a daily driver and will see limited use off-road, I would suggest you not go more than a 2" budget boost ... and I was much happier with my '88 MJ after I removed the 4" lift it had when I bought it, and set it back to stock height.

Never gets above 212? That's below normal for an MJ. What did you mean when your original post said Overheating is when the needle on the gauge is constantly in the red zone, which is around 240 degrees and up. Are you overheating, or not?

Nope. THAT sensor sends input to the ECU, but it controls whether the ECU is in open-loop or closed-loop mode. That sensor has nothing to do with the aux fan.

Leaking injector and/or bad oxygen sensor.

You were told wrong. That IS the relay for the aux fan. The ECU in the Renix-era MJs does not have any control over the aux fan -- that came in with the Chrysler system in 1991. However, the relay may not be bad. Which wires are you jumping to actuate it? For pure temperature, the relay is triggered by a sensor in the driver's side radiator tank. If that sensor is bad or there's a break in the wires between the sensor and the relay ... the relay won't get triggered. As a work-around while you diagnose the problem, you can wire a toggle switch to the relay control terminals and control the fan manually. But ... where are you located? It's January -- winter. Not all MJs even had an auxiliary fan. If you are experiencing overheating in January, your radiator is probably due to be replaced, or else the fan clutch on the mechanical fan is bad. The primary fan should be all you need this time of year.

If it's backfiring, it is virtually 100 percent certain that the timing can't be good. Check it again. Be sure #1 is at top dead center ON THE COMPRESSION STROKE, then check the distributor to see if the rotor is pointing at the #1 terminal in the cap.

The simple test would be for anyone who has an XJ or MJ box out of the vehicle to just turn the input shaft all the way to full lock (stop) in one direction, then count the number of turns to go to full lock at the opposite extreme. In the vehicles this is 3-1/2 turns for the 14:1 box, but in the vehicle there's a stop on the steering knuckle. I expect that out of the vehicle it's going to be closer to 4 full turns, but I don't know. And the only steering box I have out of a vehicle is an old one that I believe has the 18:1 ratio from the early AMC off-road option package. Once we find out how many turns for a stock 14:1 box, anything less for a box on the counter at the parts store would indicate a 12.7:1 box. Or you could buy directly from Borgerson and be sure you're getting the 12.7:1 box. http://www.borgeson.com/xcart/catalog/S ... -1384.html

If you're going to sell it, why would you even consider doing all the work necessary to convert it to 4WD? The 3.07 axle will be fine behind a 4.0L and automatic. In fact, in my not-so-humble opinion if Jeep had needed to use 3.07 gears on something, they should have been mated to the automatic rather than the 5-speed.

Ummm ... WHAT wiring harness is not right? First you're looking for parts, then you have ... something ... that doesn't match. What did you get a harness from, an XJ? What year?

For sure they don't Eagle. I tried to get a rebuilt box at a couple of the parts chain houses, and they let me try several "ZJ" boxes by turning it lock-to-lock. They were all the same number turns as my 14.1:1 ratio box. I ended up using a low mileage ZJ box from a 1996 model. That's what I was afraid of. Do you by any chance remember how many turns, lock-to-lock, for either the 14:1 or the 12.7:1 ratio box? I know the 14:1 box is 3-1/2 turns in the vehicle, but the travel is limited by the stops on the steering knuckles. Out of the vehicle, is the bare 14:1 box maybe 4 turns? I'd go dig up the one I took out an MJ several years ago, but fuzzy memory is that it was a boogered up variable ratio or 18:1 ratio box anyway, so without knowing its origins for certain I wouldn't want to use it as the basis for providing guidance on how to check a bare box for ratio.

Shackles don't add any capacity to the springs, and by allowing the springs to flex through a wider range they contribute to early spring fatigue.

Don, do you know if this holds true for rebuilt boxes from the parts chains? After all, the exterior of the ZJ and XJ boxes is the same, they are both a basic Saginaw box. Do you suppose the rebuilders pay attention to those codes when they stuff new guts in the boxes?

Is that 2 inches of lift over nominal stock height, or 2 inches higher than where you started? Either way, I'm glad it worked for you and that you're happy with it.

You may have the sequence correct, but are you sure you have the #1 wire on the #1 terminal of the distributor cap?

The hose between the master and slave, or the slave itself.

I like the XJ main leaf trick. You gain load capacity without lots of lift. Another option is that Rancho sells a full-length AAL for the XJ and MJ. It adds about 2" in an XJ, and about 1" in an MJ. I've used three of them. Last time I bought one was a few years ago and at the time it cost about $50 -- probably went up a bit since then.

229. But it wasn't really similar to the 242.

Nope.

Cherokee gas tanks and gravel shields are completely different from Comanches. You need the part from an MJ, and it has to be from the same chassis (longbed or shortbed) because the tanks are different between the two.

If the resistor pack is bad, the fan will still operate on high speed, it just won't operate at the lower speeds. Yes, it is possible for the fan motor to die. It's an electric motor -- it has an armature and brushes (so-called -- they aren't really "brushes" as we think of a brush), and the brushes eventually wear down to the point they can't maintain contact with the armature. I'm currently on the third blower in my '88 Cherokee. Auto Zone has new blowers -- the impeller is a separate part from them if you break the old one trying to swap it over.

I probably need to do this on my '88 Cherokee because the voltmeter always reads lower than a multimeter at the battery shows. But ... Remember that even after this upgrade, you STILL have a voltage meter, not an ammeter. It does NOT show you the alternator output, it only shows you the voltage in the system. By the time you see the voltage drop, it will be an indication that the alternator HAS failed, not that it's getting ready to fail.