Eagle

Temperature and oil pressure gauges in my '88 XJ read low, and have been that way for the past ten years or so. I've replaced the oil pressure sender three times, and it made no difference. Factory gauges aren't the most accurate in the universe. I regard them as more of a "GO / NO GO" indicator. As long as the needle points where it usually runs, I figure everything's okay. If it moves away from whatever it considers "normal," then I start checking things. Still better than idiot lights -- although IMHO an ideal setup would be both.

http://comancheclub.com/topic/4647-brake-bleeding/ http://comancheclub.com/topic/27326-brake-bleeding-procedure-with-rear-height-sensoring-valve/

My friend, Erich, replaced the cab-side hat sections after welding in replacement pans. IIRC he treated the concealed portions with POR-15 before he welded them in place.

Maybe ... or maybe not. Could be a bad relay, or more likely a bad ground at the horn.

The factory 2-barrel carburetor on the 2.8L was JUNK, so I don't think you did yourself any favors by replacing what was probably a much better carburetor with a 2-barrel. The 4-barrel, all things being equal, should give you both better performance and better economy if it was correctly sized for the engine. And it's tough to get better than an Edelbrock Performer manifold. If all it takes to get your engine running again is to pull a wire and then plug it in again, it certainly seems the problem is electrical. Have you tried a different set of ignition wires?

There is only one proportioning valve, and that's a distinct possibility. When you worked on the brakes, did you follow the MJ-specific procedure for bleeding, to ensure that the rear brake bypass line doesn't have air trapped in it?

Yes. 1986 Comanche FSM for the 2.8L V6. There is no valve adjustment for the AMC engines. The rocker arm retainer nut on those is torqued down against a shoulder on the stud.

Check your pushrods -- see if any of them got bent.

My brother's buddy the stock car racer always adjusted Chevy valves with the engine running. Back off until the rocker clatters, then tighten until it stops making "I'm falling apart" noises. It's messy -- there will be oil squirting around.

You're talking a few hundred pounds of gear there. Springs deflect when you add load -- that's what they're supposed to do. That's how the load sensing proportioning valve in the MJ rear brakes works. Deflecting under load doesn't mean the springs have sagged. They haven't sagged unless the vehicle doesn't come back to normal height when the load is removed. For an XJ, the measurement from the center of the wheel cap up to the bottom edge of the flare should be 17.0 inches ... with no load in the back, just a regular spare tire and maybe half a tank or less of fuel.

I would pay a lot more for a truck that DOESN'T have a lift.

Because hundreds of people have done the XJ main leaf AAL budget boost, and they ALL report that they gained 1-1/2 inches. In twenty-five-plus years of tinkering with XJs, the only one that didn't produce an inch and a half was the '88 I did for my ex-GF ... and that one produced a lift of 1-1/4 inches. Once you introduce leaves with different arch than the spring pack in the vehicle, unless enough other people have done it to have a history with whatever spring you choose ... there is no way to predict what you'll get.

The reason turning the key to the START position seems to turn everything off is that turning the key to the START position turns everything off. As the saying goes, "That's a feature, not a bug." The system is designed to operate that way. The one thing that should continue to function when cranking (besides the starter motor itself, of course) is the fuel pump. But that brings us to another little part that can create problems: the fuel pump ballast resistor. I don't know if it can go into an intermittent failure mode but ... why not? During normal engine operation, the ballast resistor drops the voltage to the fuel pump to about 9 volts to reduce noise. During engine cranking, there's a bypass circuit that sends a full 12 volts to the fuel pump. In the case a really bad ballast resistor, the engine will start when the fuel pump runs during cranking, then after the key is released to the RUN position the fuel pump cuts out and a few seconds later the engine dies. The 87 4.0L didn't have a ballast resistor. It's safe to run without it, so you could try jumpering yours and see if it makes a difference.

If you're going to scavenge anyway, IMHO it makes better sense to scavenge for something that will generate predictable results. Sure, any 2-1/2-inch wide spring can be stuck in there ... but there's no way to know until you've paid for the springs and done the work what the result is going to be. With the XJ spring, so many people have done it that the result is well known in advance.

The rear adjusters were likely your problem. The rear drums should be adjusted just to the point of VERY light contact when rotating the wheel when the brakes are not applied, then back off like one click. The self-adjusters generally don't self-adjust, so you should check the adjustment every six months or so -- or more often if it's a daily driver.

Well ... yes, but no. Not really. There are two advantages to using the XJ main leaves, and they are related. Using leaves out of another set of XJ springs means that the arch is correctly matched to your springs, so you don't have the AAL fighting against the other leaves in the pack. The other advantage is that you pretty well know how much lift you'll get: 1-1/4" to 1-1/2". If you need more than an inch and a half, then you can either use multiple leaves from the donor XJ packs, or go with leaves that have more native arch. The problem is that the one leaf with more arch is doing a lot of work, and it may get fatigued and sag fairly quickly. It's much better if the arch in all the leaves matches.

Nope. Much too big, and way too many wires.

The best "budget" lift for the rear of an XJ (IMHO) is to get another set of XJ rear springs. Take them apart, cut the eyes off the main leaves, and use them as AALs. The prevailing wisdom from NAXJA is that this produces 1-1/2" of lift. Several years ago I rebuilt an '88 XJ for an ex-girlfriend and I did the home-brew AAL because the rear had sagged about a half inch. The second set of springs came out of an '89, so both sets were old and had miles on them. The AAL grossed 1-1/4 inches. Since I started out a half inch down, the net was 3/4-inch higher than "stock," or just about where the Up Country option would be on a late-model XJ. This approach reinforces the full length of the main leaf, so in addition to gaining a modest lift and additional carrying capacity, you also get a much stronger (in the sense of resistant to damage) spring pack.

Very bad idea. If the springs are already sagged, a longer shackle will ensure that the springs become totally trashed in a very short time. Before trying to throw money in the wrong direction, start with figuring out what it needs. Measure from the center of the wheel/axle to the underside of the flare on both sides and report the measurement. It should should be 17 inches. Once we know what it is, we can brainstorm ways to correct any problems.

Except for really base models that only have one horn (and thus one tone), most vehicles have either two or four horns. Most have two -- one high and one low. Without a sound clip it's impossible to describe the difference, but if you ever hear a vehicle with a single-tone horn, you'll immediately know the difference between it and a dual-tone horn. First step to knowing what you need is to figure out what you've got -- or what you're supposed to have. Most MJs and XJs had two horns, mounted to the lower radiator cross brace. One is the high tone and the other is the low tone. I've never tried to figure out which goes on which side. If you have to replace both horns, it doesn't matter -- you'll need one of each and it doesn't make any difference which one goes where. MJ horns are one-wire -- they ground through their attachment to the chassis.

^^^ Just buy yourself a good set of wires and any cap & rotor with copper/brass (not aluminum) contacts and you're good to go.

Whereas Clayton is an industrial engineer who developed his longarm setup specifically for his own, personal ZJ Grand Cherokee. It had to be bullet-proof, because when Clayton wheels he's an animal. It worked so well that other members of his local club started asking him to make copies for them. Pretty soon he had convinced his company to let him take over an unused corner of the warehouse, and Clayton's Offroad was born. A few years later they moved into their own quarters.

I don't think an '89 ECU will make a difference in an '88 vehicle. The bump in horsepower and torque was from the '87 model year to the '88 model year.

The needle should be straight up at operating temperature. That said, the nedle in my '88 Cherokee has read low for at least five years. I probably need to refresh the grounds to get it accurate again, but I haven't had time. I don't think it's wise to start trying to diagnose a problem without even knowing if there is a problem.