Eagle

The oxygen sensor is the one that's most likely to put the fuel mileage in the toilet. A tune-up never hurts, but won't usually flush the mileage THAT badly unless it gets to the point that the engine hardly runs. A bad O2 sensor, on the other hand, just leaves it running rich all the time. Fast idle is usually the IAC or the TPS, but it can also be rust in the throttle linkage bellcrank on the driver's side of the engine, down below the master cylinder. Try spraying that with a good penetrating lubricant (NOT WD-40).

This is in an 87? How can the gauge have spun like a propeller -- it isn't a center pivot gauge, the 87 should be a bottom pivot gauge and it only swings through about a 90 degree arc. I had an 84 XJ 4-cyl that DID have a center pivot gauge, and that one gyrated wildly. Turned out the connector that pushes onto the top of the sender was fubar. I cut it off, soldered on a ring connector, and used a nut and lock washer to make the connection (the post on the sender is threaded, thankfully). End of problem.

LOL I have three dial calipers, two digital calipers, and a couple of micrometers. But front sway bars are usually dirty and messy, and I just don't see the point of measuring to three decimal places when the tolerance is an eighth of an inch. The open end wrenches are handy, easy to use, and easy to clean up after "measuring."

Don't feel too bad. Many years ago I had a friend who was a carpenter for a construction company, so he was always driving his pickup around construction sites. Which, of course, meant rocks, stumps, and "stuff" all over the place. The "best shop in town" replaced a rear axle brake line for him, and they did it just like you did -- except that they left it hanging DOWN with about 2 inches of ground clearance. Ron couldn't understand why I went ballistic and told him they were idiots.

Keep in mind what other guys told you. On the 88 that plastic coolant bottle is NOT an "overflow" bottle. It is an integral part of the cooling system, coolant flows through it, and it is under pressure. do NOT remove that cap when the system is hot and under pressure.

All four were not used on the MJ but they were used on the XJ. The biggest one was used on the XJ Wagoneer Limited. To measure I just use a set of open end wrenches. Whichever one barely fits onto the bar (and sometimes it's almost a light press fit) is the size of the bar.

For starters, you are NOT overheating. The normal temperature for a 4.0L is 210 degrees. You did the plug and unplug deal and the gauge responded, so it's not totally fubar. Inless you have some resistors that you can use to test the range of the gauge, the next thing would be to replace the sender in the head. Wait -- there is another test you can run. The gauge is basically an ohmmeter. The temp sender for the 88 has a range of 0 to 88 ohms. I think it's zero when cold and 88 to max out the needle on the gauge. So you can use a multimeter to check what the sender is sending. Connect one lead to the head, and touch the other lead to the tip of the sender, where the wire pushes on. When the engine is cold it should read close to zero. At normal operating temperature, it should be in the area of 42 to 45 ohms.

Yeah, they do. I have three sets for an MJ D44 in a box in my garage. Took them a couple of tries to get it right. The first time they said "Yeah, we have a pattern. No problem." I think the pattern must have been for a J truck. So I returned those along with the original lines off an axle and they matched them up pretty well.

You can get stainless. In the back of all the car and 4x4 mags there are two companies that always advertise. One is Classic Tubing, and I don't remember the other. They specialize in making up custom sets to the OEM bend profiles (sometimes they even do it right), but I believe they will also sell lengths of straight tubing.

Which coolant temp sensor did you replace? If your MJ is a 90 or earlier, there are two. The one on the side of the block supplies input to the ECU but not to the gauges. The one for the gauge is the one in the rear left corner of the head. Could also be a bad wire. If the wire is shorted it'll go all the way to one side of the gauge, if it's an open circuit it'll go to the other side. Don't remember which way, though.

Two things to think about: (1) The tilt columns are prone to having the internal lock screws loosen up, which then requires pulling the steering wheel, horn mechanism and lock plate to tighten up so the wheel doesn't flop all over the place. There are write-ups for this all over the Internet, as it affects all that vintage GM steering columns, not just the XJ and MJ. (2) For the vast majority of people, the "straight" position is the most comfortable position anyway. Knowing the above, there's no way I would spend money or effort to install a tilt column in place of a standard column.

I towed a LWB home with my SWB. Towing wasn't too bad, except up steep hills, but stopping was a problem. I've never seen a dolly with brakes but if you can find one I would highly recommend it.

This is why converting to rear disc brakes doesn't make any sense to me. Even in an XJ, which has more weight over the rear axle under normal conditions, the rear brakes only do a small percentage of the actual stopping. In an unloaded MJ, the rear brakes do almost nothing. Converting to rear discs and then having to deal with the resultant fluid and pressure issues just seems like an exercise in futility. I guess if you're doing the 8.8 conversion and it comes with disc brakes you're sort of committed, but IMHO it's cheaper and easier to use a Chrysler 8.25 out of a 97+ XJ and leave the brakes alone.

Both bgred2 and Twisty are in Massachusetts, so I'll suggest you both head over to Henry's in Blackstone, MA. It's a combination u-pull and "they pull" yard. I haven't been there for awhile, but they generally have a huge area of XJs and MJs back in the u-pull section of the yard.

All the XJs use rear drums. I suspect the 8.8 calipers require a LOT more fluid than the old wheel cylinders. The ZJs used rear disc brakes. I would suggest getting the master cylinder and the front combo valve from a disc brake ZJ and using those.

The heater core is probably blocked.

Because a T5 and an AX5 are both 5-speeds, but an AX4 is a 4-speed. JeepCo, what's the VIN on that 2.8L 4-speed? I'm not doubting that it came to you that way, but since I know what could and could not be ordered from the factory back then, I don't think it was factory.

HESCO has an adapter to run the CPS off the front of the engine. It's designed for converting a carbureted 4.2L to EFI but there's no reason it can't be used to run an odd tranny behind a 4.0L.

Rusty uses the cheapest Chinese TRE he can lay his hands on, that's why they break. To get the truck back on the road, just buy a replacement TRE from an auto parts store and stick it in there. Does the driveway have an approach angle? Were you turning in when it broke, or going straight? It's quite possible to flex out a suspension turning into a steep driveway. The TRE shouldn't break ... but with cheap Chinese parts, anything is possible (except good performance). When you install a new one, be sure to check the tapered hole in the frame bracket. If there's any crud in the hole, it can prevent seating the TRE in the bracket, and that could be one reason for not being able to tighten the castle nut far enough to insert the cotter pin. FWIW, I would never drive a vehicle w/o the cotter pin. Loc-tite is good stuff, but I'm not brave enough to use it as a replacement for a mechanical safety like a cotter pin.

Everything I'm seeing about this is wrong. First, the TRE broke where it goes into the track bar. A loose castle nut canNOT cause that. But having the TRE bind up because you flexed it beyond its range of motion. How much lift do you have and were you flexing it out when it broke? What's this about having to put on three or four more turns to line up the castle nut with the hole? A castle nut has six slots. If the hole is already visible, the most you should need to turn it as about 1/12 of a revolution.

x 10! A friend of mine lost his MJ that way. He knew the injectors were leaking, so he drove it to the dealership to buy the o-rings. When he walked out of the parts department, the truck was in flames.

Your system is working in reverse. The front (larger) hose is the crankcase intake hose. The small hose off the back of the valve cover is supposed to be the suction hose. When this gets clogged, there's no vacuum being pulled so the crankcase gets pressurized by blow-by and pushes oil out the inlet ... and into the air cleaner box. You need to replace the rear line, but there is a baffle inside the valve cover that is probably clogged, too, so the right way to do it is to remove the valve cover and clean out the inside -- and the baffle -- when you install the new hose.

I'm going to guess a 231 with a disconnect front axle and a vacuum leak.

I was looking at having my XJ shipped out to Moab for the annual NAXJA event a couple of years ago and the best price I got was $600 -- each way. I'm sure with rising fuel costs it would be closer to $1000 by now. I didn't do it, so I can't provide any experience, positive or negative.

The little lever to release the key is used only on the manual transmissions. On the XJs with automatic (and the MJs with floor shift) that function is handled by putting the floor shifter into Park. Finding a column with no key is not a reason to run away. If you got it with a key, most likely it would only have ONE key, and the key would be so badly worn that you could never get a good copy made from it anyway. Pep Boys and the other parts houses sell replacement lock cylinders for about $10 (maybe a bit more now, I bought mine a few years ago) and it's a fairly easy job to install. Much easier with the column out of the vehicle.