Eagle

Oh, yeah. Most definitely. This is NOT something to take lightly. If your injectors are leaking, do NOT drive the vehicle. Do not even start the engine. The fuel from the leaking injectors drips onto the hot exhaust manifold and ... POOF! Crispy critters and roasty toasties. If you think you smell gas around the front of the vehicle ... open the hood and find out where it's coming from before you allow the truck to self-immolate.

I sort of agree regarding abstaining, but why is voting FOR someone you think deserves to get votes in any way irresponsible? This country's two-party system is corrupt and has been hijacked by special interests. If more people would vote for third (or fourth, or fifth) party candidates, maybe the big two would start giving us some real candidates again.

There are two possible places where they leak: (1) the O-rings, and (2) the connection between the metal portion of the body and the plastic portion. If the metal-to-plastic bond lets go, there is no possible repair. This is not a new problem. I watched an XJ burn up in front of my then-GF's house ten years ago, and a couple of years after that a friend in NAXJA knew his injectors were leaking but drove his MJ to the dealership to buy new O-rings. He walked out of the parts department to find his truck in flames.

Politics in Jeep forums is a bad idea. Sorry, but I'm not playing ...

It isn't an alternator gauge. It's a voltage gauge. It reads the voltage in the wiring at the instrument panel. Occasionally, if there's corrosions in various connections, the gauge reads low but the alternator is putting out the correct voltage if you test at the battery. I have that in my '88. Don't know why yours would be completely dead. Put a known 12-volt source directly to the two posts on the back of the gauge and see if it gives a reading.

A complete circuit runs from the positive terminal of the battery to the device (ideally through a fuse) and perhaps a switch of some kind) and then back to the negative terminal of the battery. If the "wiring" ends somewhere on the chassis before getting to the negative terminal of the battery, and corrosion in any way and at any point interrupts the flow through the chassis or from the chassis to the battery -- you don't have a circuit. Your idea of using a multi-terminal bus and wiring the grounds directly to the battery using (I hope) copper wire of suitable gauge is far superior to the OEM wiring. The only reason the manufacturers do it the way they do is because it saves a lot of wire, and wire costs them a few pennies per vehicle. Go for it.

There are spacers, and then there are spacers. The type you can buy for a few bucks at Pep Boys are dangerous. The ones that sell for $50 to $100 each are machined, aircraft-grade aluminum alloy and will probably outlive an MJ. Just be sure you're getting the good ones and you'll be fine.

Enough to keep it from falling out when the suspension droops, and still have enough spline engaged to drive the truck without shearing off the splines. But you also have to remember that the suspension compresses, and as the suspension compresses it shoves the slip yoke deeper into the transfer case. You need to cycle your suspension to the bumpstops and make certain that the yoke is going to be smashed into the tailshaft or tailshaft housing at full suspension compression. If you have a big lift, with a correspondingly high driveshaft angle, and a very flexy suspension, the yoke may actually move more than your yoke and tailshaft can accommodate. If that happens you have two choices: (1) Install limiting straps and/or bump stops to reduce the total amount of suspension (and thus yoke) travel; or (2) Install a slip yoke eliminator and have a drive shaft made up with a long slip spline in the drive shaft.

The polarity of the sender was reversed in the 91+ as stated above. There is a 3-pin connector on top of the fuel tank. The sensor (variable resistor) outputs to the gauge are pin A (ground, BLK wire) and pin B (variable resistance out, BLU wire). The wire colors may be different for your model, but the pins should be the same. Swap these two wires and it should work correctly. It still will not be 100% accurate because the sensor resistance values are different between the two, but at least the needle will go in the right direction. :D ^^^ What he said.

Hornbrod - I studied your diagram and I couldn't see where it routes power for the relay control feed through the headlight circuit. After reading your post three times, I figured out that you're assuming there is an existing fog light harnbess in the vehicle to tap into. Dunno what they did in 1991, but in the AMC years the fog light harness was not included. If you added fog lights later, you had to buy the complete harness, or make your own. And the factory harness worked for FOG lights, but was backwards for driving lights. This thread asked about "driving" lights. I was interpreting the original post in this thread as meaning that there isn't a harness already in the vehicle, so the OP is starting from scratch.

Assuming you still have the OEM plastic surge tank, replacing just the cap is not going to resolve the problem. The tank and cap should always be replaced together.

Keep in mind the difference between "fog" lights and "driving" lights. By Federal (and many states') law, "driving" lights may be on only with the high beams, and MUST shut off automatically when you dip the headlights to low beam. They cannot operate when you only have the parking lights on. "Fog" lights are the opposite. They MUST shut off when you flip the headlights to high beam, but they may operate when you only have the parking lights on. Which means you need a bit more than a toggle switch and a relay to control them properly.

IMHO -- not a chance.

On both my XJ and my MJ I have tried replacing rusted-out sections of brake line, only to have another section explode while trying to bleed the brakes after the repair. Do NOT try to save pennies by using junkyard brake line.

If he got the pinion depth and the backlash within spec, he doesn't have a carrier break issue. If he had the wrong carrier it would be physically impossible to set up within spec.

In your state, are body shops licensed as auto repair shops like dealerships and repair shops? If so, report the shop both to the Better Business Bureau and to the state agency that handles the licensing. If there's no license, you can still report them to the BBB. I think your best bet, especially since you seem to have as many MJs as I do, is to learn to do body work. For a lot less than you paid for that job, you could have purchased a high quality gas/wire welder that would enable you to do your own repairs and know that the rust was repaired with metal.

Do you still have the original cooling system, with the plastic reservoir on the passenger side of the firewall? If so, one possibility (probability, more likely) is that the cap isn't able to hold pressure any more. In the 87 - 90 4.0L cooling system, that bottle is not an overflow recovery bottle. It is a part of the pressurized system, and that cap is a pressure cap. When they get old, being plastic, they lose the ability to seal. The other point is ... how full do you fill that reservoir? There is NO overflow for the "closed" system -- which is why it is nick-named the "closed" system. There has to be air in the system to allow for expansion. If you look into the opening in that reservoir bottle, you'll see a post sticking up. That's how full you should fill it when the system is cold. It fills to the halfway point of the bottle, with the additional volume to allow for when the coolant gets hot and expands. If you've been filling it up to the top -- you've been over-filling it, and stressing the pressure cap in a way it wasn't designed to be stressed. Quadratec used to sell a complete replacement (plastic) bottle for $19, with cap. It's probably a few $$$ more now, but ti's still the cheapest way out. There are other solutions available using high quality aluminum parts, but they're a LOT more money. If you're interested, I'm sure a search will turn up the discussions.

A Grand Cherokee will have the larger shafts (I think), but it's a low pinion, so it's not much of an "upgrade."

It will also require a complete engine wiring harness, and it may involve some alterations to the chassis harness, as well. For example, the V6 has a mechanical fuel pump. You'll have to get power to the tank for the electric fuel pump. Oh, yeah -- you'll need a gas tank and fuel pump.

I agree. That truck is far too nice to scavange parts off for some other rig. I'd keep it, put a fresh coat of paint and some good rust-proofing on it, and use it as a summer daily driver. The 4x4 will get you through the winter, and if it already has some rust then a bit more won't kill it.

The temp sensor and the oil pressure sensor for the gauges would be the same for an 86 as for an 88. That's not the problem. Begin by testing the gauges themselves. You'll need an assistant. For either gauge, the sensors are variable resistors. The range is zero ohms to 88 ohms. Zero ohms, of course, is no resistance, or a short circuit. So, as a rough "go / no go" test, you turn on the ignition (the engine can be running, but be careful where you put your hands. The engine does not NEED to be running, but the ignition has to be on.) Take the wire off one of the sensors. You now have an open circuit ==> infinite resistance. The needle on the gauge should swing all the way to the right. Now find a clean, dry place on the engine block and touch the wire to the block to ground it. You now have zero resistance. The needle on the gauge should swing to the opposite end of the scale. Repeat for the other gauge. If the gauge fails this simple test, you have a faulty gauge, or a break in the wiring between the gauge and the sensor. If you know the idiot lights worked before, the wiring should be good. Problem is, you have no way of knowing whether or not the idiot lights actually worked, because the start-up test only checks the bulb, it can't check the circuit. Let us know what you find.

XJ flares won't work in the rear. They are about 2" too short lengthwise, and about 1-1/2" too short in height. To use XJ flares, you would have to cut out the flare area from a 2-door XJ and graft it onto the MJ to reduce the size of the wheel opening.

I believe I used '95 YJ hoses in the '88 MJ when I had the lift in it, too. Had to re-bend the hard line on the caliper end slightly, but the fittings went together and they were plenty long enough for a 4" lift.

The '96 is a mongrel. That was the first year they went over to OBD-II, and the way they did it was sort of bastardized because it was adapted into the 91-95 chassis harness. The '97+ was an all-new harness. You need a harness from something in the 1991 to 1995 range.

If the backing plate is the same, then the axle length is different. Several years ago I got my hands on a Dana 44 rear axle. It had backing plates, but no drums. "No problem," sez me, "I'll just use the skinny D35 drums until I can afford new D44 drums." Visually, there was definitely more of a "bell" shape to the center web portion of the D35 drums than on a nearby D44 axle. I was sure it would work -- but it didn't. The back (open rim) of the drums bottomed out on the backing plate before the center "hat" made contact with the axle hub. So either the backing plates are different, or the D44 axle shafts are longer (or the D44 axle tubes are shorter -- hadn't considered that possibility before). Something is different, 'cause it didn't work like it was supposed ta.