Eagle

The factory specs are for a hot engine (normal operating temperature). Did you take your mechanical readings hot, or just after a cold start? 13 psi is a factory minimum and most 4.0Ls idle around 25 to 30 psi, and most in decent condition run about 50 to 55 psi at normal (within speed limits) highway speeds. Your idle pressure sounds higher than normal, but if you measured it cold you're comparing apples to pomegranites.

The spark plug leads are the same, but the coil wire for the HOs is shorter than for the Renix and if it is an OEM-length wire will not reach the coil in the '90.

If the height sensing valve were hooked up, you would have no choice if you wanted your brakes to actually work. Since it's not hooked up, you should be able to skip that step. But how did you deactivate or by-pass the rear height-sensing valve? Are you certain you by-passed it correctly? If not, you might be surprised to find that you have NO rear brakes, and that you will be unable to bleed the rears.

JC Whitney used to sell MJ quarter panels and patch panels. I don't know if they still have them, but if Whitney had them, someone is making them and they should be available from some of the on-line body parts supply houses. Cherokee sheet metal won't fit. The distance between the crease and the top of the wheel arch is different. Been there, tried that, did not win a t-shirt. Yeah, I know it looks like the XJ panels will work, but it's a cruel joke played on us by the designers. No matter what part of an XJ panel you try to fit up to the rear of an MJ, it just doesn't quite fit.

I'm assuming you have the Renix style ("closed") cooling system, with the pressure bottle on the firewall (passenger side)? The system has to be "burped" to purge trapped air. Start with the engine cold, because that bottle is NOT an "overflow" catch tank, it is part of the pressurized cooling system and if you crack the cap when the system is hot, you'll be in a world of hurt. Remove the cap, set it aside, and fill the tank to the top of the post inside (half full). Start the engine and let it warm up with the cap off. This means don't stand too close. As soon as it heats up to the point of bubbling, shut off the engine, then stand by. After about one to three minutes, as the system cools down it will begin to suck fluid out of the bottle into the system. As the level goes down, pour in more coolant, keeping the level to the half-fill line. Stop pouring when the system stops taking in coolant. Repeat. It'll probably take you about four cycles to purge most of the air. Be very careful when pouring in the new coolant, because the stuff in the bottle will be hot enough to scald you if it splashes. Wearing heavy rubber gloves (the kind used in labs for working with acids, not latex or nitrile exam gloves) can help a lot if you can access to them.

Rough Country has a reputation for broken coils that is unmatched by any other XJ/MJ aftermarket parts supplier. They are possibly the only supplier more universally reviled than Rusty. If you have had good luck with their products, count yourself fortunate.

I beg to differ. I bought my '88 XJ new. It has the rocking chair seats, and I know I didn't pay for them. They were standard on the Pioneer, Chief, and Laredo models.

Agreed, the problem is the extra height added by the "rocking chair" hardware. You'll have to get rid of that to get the seats down to a "normal" height. Dunno what year Jeep stopped offering that, but buckets out of an early to mid-90s XJ would probably not have them.

I run Castrol Syntec and change oil and filter at 5000 miles. I changed at 2500 miles with conventional oil. My brother used to be a service manager at a BMW dealership. He switched over to synthetic a lot sooner than I did (of course, he could buy BMW's oil at wholesale prices), and when he pointed out that BMWs recommended oil change interval with synthetic is 15,000 miles, I figured I'd be safe using 5000 miles.

What's wrong with a new body-style Cherokee? The 97 and newer with the restyled interior are quite comfortable, get decent gas mileage (not outstanding, but on a par with the other vehicles you've mentioned), they ride nicely and the interior has more "creature comforts" than the early XJs and MJs. Including dual air bags.

That didn't matter when I talked to the collector insurance companies. My plan for the '87 is a full restoration and display in AMC Owner Group shows. I not only have newer daily drivers, I also have other 4x4s for use on the occasional off-road excursion. The insurance people would not talk to me. Period. Didn't even matter if it had antique tags on it.

What's an AX-15 specific clutch?

Do your homework -- and if you can actually buy collector insurance for a Comanche, please tell us where. I tried a couple of years ago. Both Taylor and the other big name in collector insurance (the name escapes me at the moment) flat-out refused to insure any 4WD or off-road vehicle. Didn't matter what age, what condition, how many "primary" vehicles I own, or how much I might be willing to pay. They wouldn't even consider offering a quotation. Nope. Nyet. Non. Nao. End of discussion.

Pretty simple test. Despite the amperage of the starter, the circuit still only carries 12 volts. Hook the hot lead of a test light to the OUTPUT terminal of the relay (the one where the wire to the starter motor connects), and connect the ground from the test light to a good ground. Have a helper turn the key to the START position. If the test light lights, the relay is making a circuit. If the test light doesn't light ... it isn't.

Yeah, me too. I also try to keep my speed at just about 2 MPH over the posted limit (just enough to make up for the built-in speedo error -- if I'm in a Jeep that I know reads slower than actual speed, I adjust accordingly) with the aim of actually driving right at the limit. Takes a few minutes longer to get there, and some people find it annoying, but it avoids traffic tickets. Back to the original post, though -- I second the advice given above, to always fight a speeding ticket. But ... if you can't afford an attorney, you pretty much MUST spend some time in a library to look up the regulations on the use of radar guns. It probably won't be in a statute book -- it's more likely an administrative regulation adopted pursuant to a statute. And it may not be grouped with motor vehicle regulations. I would expect it to be grouped with police procedural regulations.

I'm not talking about forcing a spring into or out of position, I'm only talking about spreading two adjacent coils far enough apart to slide a bump stop between them. With the frame on a jack stand and the axle drooping, it shouldn't require much "persuasion" at all. Yes, I have seen what a coil spring can do.

I sometimes wonder about that same question ... not as a legal issue, but more as a reflection of human behavior. I am not a lawyer nor a police officer, but I'be be willing to bet (and I'm not a betting man) that the limit changes at the point where the post is staked into the ground, NOT however far down the road you can see the higher limit from. The commentary on the contrary nature of us homo sapients, though, is that we (and I include myself) want it both ways. If we see the sign a hundred yards ahead, we want to speed up to the new limit NOW if the new limit is higher, but how many of us treat it the same way when the new limit is lower? Not me. If I'm coming off a 50-MPH stretch of road into a settled are where the limit is 35, I slow down to 35 when I get to the sign, not before. So, to be fair about it, when the limit goes back up to 50 I can't honestly claim I should be subject to the new limit as soon as I can see (not even read) the sign.

Por supuesto :cheers:

What year is your truck? On the Renix, there is NO connection to the factory thermostat. The aux fan is controlled by a sensor that screws into the bung in the driver's side radiator tank. The sensor is basically an ON-OFF switch, which in turn connects to the control side of a standard relay that's mounted to the inside of the driver's side fender. With the 91+ Chryco system, the aux fan is controlled by the ECM. You'll need a factory wiring diagram to figure out where to tap into the wiring harness to access that circuit.

Yeah, I've done it that way. You may need to spread two adjacent coils a bit by applying "persuasion," but it's not that difficult.

Running heavy liquid lube in place of lighter liquid lube is one thing -- using a totally different formulation where pumps and hoses are involved is another. I've seen what happens to a brake system when some doofus puts automatic tranny juice in the master cylinder. It's especially exciting at night -- ever see front brake rotors glowing cherry red? I would have suggested the turkey baster, too. Good job getting that stuff out of there.

Age does factor in, but not directly. Regardless of age, the insurance company will "total" a vehicle if the cost of repairs would exceed their estimate of the replacement cost of a vehicle. Obviously, for a 20-year old, high mileage vehicle, the replacement cost is much lower than for a brand new vehicle just off the showroom floor. For a $35,000 new car, a $3,500 repair is nothing. For a 20-year old MJ, a $3,500 repair is five or more times what the blue book says the vehicle is worth. This is why, if you put a lot of money into repairing or restoring an older vehicle, you should document everything with both receipts and photos, and keep the insurance company informed that your 20-year old clunker should not be considered the same as the rust-bucket on the next block. You may pay a bit more in premiums to have the increased replacement value covered, but if you need it it's nice to get the real value covered. FWIW, those of us who drive and love older vehicles face the same problem even (or especially) if an accident is NOT our fault. If an accident is caused by another driver, that driver's insurance company is not going to want to spend a nickel more than they have to, so if they can total out your 1988 Comanche for a $500 lump sum payment rather than ante up for a $3500 repair bill ... guess what they'll choose. In such a case, if you still have your own collision insurance and have documented that you have recently put more than $3500 into the vehicle, you can choose to have the vehicle repaired under your own insurance and all you pay is the deductable. Your insurance company then goes after the other company through a process called "subrogation." If they recover (which they usually do), they will then refund your deductable. That's the main reason I keep collision coverage (which is "collision" coverage, not "comprehensive." Comprehensive covers fire, theft, and natural disaster, not accidents) on my older vehicles. I run a fairly high deductable to keep the premiums down, but I consider all of my XJs and MJs to be worth more than "book" value and I do not want some dipzhit, fly-by-night insurance company to steal one from me if their insured driver plows into me in a drunken stupor some night. $500 is NOT going to buy any of my Jeeps.

I'm going to make my own. I have three 2WD MJs here at the moment. One runs and drives just fine but I'm not interested in upgrading it. The other two I regard as keepers. Whether or not I ultimately convert one or both to 4WD, I want to improve the rear spring capacity. The plan is to take old XJ main leaves, cut off the eyes, and stick them into the MJ spring packs as AALs. I'm actually hoping this will increasse the spring rate without adding much lift, but there will probably be some net increase in ride height. For those wanting some lift, doing the same thing but using old MJ, S-10, or older Dakota main leaves should generate some lift. When you add a second main leaf to an XJ leaf pack, it generates about 1-1/2" of lift. I would expect a similar result adding a second main leaf into an MJ leaf pack, but I haven't done it (yet). Or just buy the Rancho XJ/MJ AAL set for around $50. The Rancho catalog says it produces 2-1/2" of lift. But ... it says the same thing for the XJ and, since one is SOA and the other is SUA, thats clearly impossible. I called Rancho awhile back to clarify that, and the nice engineer gal I spoke with went off and checked with some other engineer type, then came back and said that should be 2-1/2" for the XJ and 1" to 1-1/2" for the MJ. IMHO the Rancho kit is the cleanest way to go. No junkyards to slog around in, you don't use up $25 worth of cutoff wheels or sawzall blades chopping the eyes off old leaves, just buy it and go. The kit includes new center pins and a couple of spring clips, although I would probably add a couple more clips for security (unless I was looking for a lot of flex).

Changing a few sensors HAS to be cheaper than doing a cam. You have to pull the head to do a cam in the 4.0L engine -- there's no other way to remove the lifters. You wouldn't pull the head and install a new cam without doing a valve job. And my experience has been that doing a valve job on a tired engine without doing a lower end rebuild results in higher compression, which then starts pushing oil past the tired old piston rings. In short -- I recommend not doing a cam unless you rebuild the entire engine. 19-pound Ford 5-liter injectors seem to be a popular replacement for the Renix injectors. The flow rate is close enough, and the FoMoCo injectors have a better spray pattern so the improved atomization may improve mileage slightly. The O2 sensor is intended to be replaced approximately every 75,000 to 80,000 miles. The original in my '88 XJ went a lot longer than that (actually, the ORIGINAL original failed a lot sooner but was replaced under a recall program, the corrected part lasted a lot longer than 80,000), the next one lasted less. If you don't know how long yours has been in place, it should be replaced because when it fails the mix gets too rich and the unburned fuel then destroys the catalytic converter. In your situation, I'd suggest O2 first, if that doesn't improve mileage check the cat for blockage, and if that's good then think about the Mustang injectors. Also check your EGR valve.

Yeah. At least in French if a word ends with 'A' it's feminine and if it ends with 'O' it's masculine. Spanish? No joy, GI. So does Spanish. The word "crear," for example, means both "think" and "create." There are many, MANY others. It doesn't help that each country in South America has evolved the language a bit differently, so the dictionaries and phrase books we see here in the U.S., which are geared primarily to Mexican Spanish, can be quite incorrect in Chile, or Argentina, or Peru. Earthquake in Chile is "terremoto." In Peru it's "sismo."