Eagle

No, I don't. What a lot of people don't understand is that the purpose of the thermostat in an automobile is to keep the coolant temperature UP, not down. If your system stabilized and was able to idle for a half hour without the temperature climbing into the red, it would probably sit there all day. Your thoughts about air restriction are valid, but they apply more when the vehicle is moving, and they apply most when you're moving faster. I used to have a full-size Cherokee 360 with a snow plow on it. On COLD winter days I could plow long driveways and clear turn-arounds and parking areas with no problem. BUT -- when I lifted the plow to drive down the road to anyplace more than a mile or so away, the temperature would climb into the red very quickly. With the plow down and working, the fan could pull plenty of air through the radiator. With the plow off, air could get to/through the radiator with the truck moving down the road. The plow, unfortunately, "plowed" air away from the radiator. It created a low pressure zone so even the heavy duty fan couldn't pull any air through the radiator. The faster I drove, the LESS air could get to the radiator.

Don't pull relays, use a VOM and check fuses. See what's pulling current with the ignition off.

NGKs are best in the Jeep engines -- the non-platinum, plain vanilla plugs. Second best is Champion truck plugs.

Vacuum leak. Probably a bad booster. Dunno why you can't get a decent peddle with the engine off, though. The rear height sensing valve was removed by a previous owner? What outlet on the front metering block did he retain for the rear circuit, and how did he block off the unused port? The MJ originally had two separate lines from the front to the rear. One fed into the height sensing valve, for normal operation. The other was a bypass line that provided full brake power to the rear wheels if the front circuit failed. A lot of people eliminate the wrong line.

Blue88, he asked about a traction bar, not a sway bar. As previously commented, traction bars have their place. For a stock vehicle running on stock (or near stock) tires, things are all pretty much as the manufacturer designed it so we can probably safely assume that it pretty much works. Go to a SOA and a lift and much bigger tires, and everything changes. And ALL the changes are bad for the springs. All the changes allow the tires to apply more twisting torque to the springs. Just think about the effect of tires. Stock MJ tires are approximately 29 inch diameter. A jump to 33-inch tires changes the diameter by 4 inches and the radius (which is the lever arm) by 2 inches. With NO other changes, a jump to 33-inch tires increases the torque transmitted back into the springs from the axle by 13.8 percent. Then consider that with a SOA, the centerline of the axle is farther away from the main leaf than when running SUA -- I haven't run the numbers, but there's another torque increase. There's no question that a lot of people don't run traction bars, but they ARE a good idea. If you can't run one, be sure your springs have the long, thick overload leaf on the bottom, because that will help considerably to resist spring wrap.

One of the MAJOR downsides to that nose is the headlights. You'd get more light on the road with a quartet of kerosene railroad lanterns. Plus -- they're very hard to find. Burn one out and you won't likely find a replacement in Wal*Mart.

What you are describing was used for only a couple of years on the XJ Wagoneer. It is not a "Renix style," and it was never offered on the Cherokee or the Comanche. Somebody swapped it on, so you can certainly swap it off. The real question is how the person doing the swap wired the headlights. If you're lucky, he just tapped into the existing wires to feed the second lamp on each side and you can just remove the taps and be done. If he actually cut anything, you'll have to figure out what he cut and UNcut it. The rest of it is bolt-up. Just keep in mind that Chrysler changed the design of the header and trim pieces in 1990 or 1991. Either type will work as long as everything comes from the same generation of donor vehicle, but you can't (easily) use the grille and trim from one in the header panel from the other.

Considering that the Mopar CPS operates on a completely different theory than the Renix CPS, I'd be surprised if there's any signal at all to trigger a timing light.

The 2.5L used a conventional PCV valve, and the 4.2L version of the I-6 used a PCV valve. I've always wondered how it would work to just use a PCV for one of the older AMC sixes.

That's pretty much it -- multi-port injection (one per cylinder) rather than a single injector in the throttle body. I don't know, but I would expect that the head got the same port revisions the 4.0L got when it went from Renix to Mopar. The change affects both injection and ignition, so you would need all under-hood wiring and the Mopar ECU to make it work. The MPFI version was rated for quite a boost in power -- The original carbureted version was rated as producing 105 horsepower at 5,000 RPM and 132 foot-pounds of torque at 2800 RPM. The throttle body injected version produced 117 horsepower at 5,000 RPM and 135 foot-pounds of torque at 3,500 RPM when it was introduced in the 1986 model year. This was raised to 121 horsepower at 5,250 RPM and 141 foot-pounds of torque at 3,250 RPM for model years 1987 through 1990. The final, multi-port injected version produced 130 horsepower at 5,250 RPM and 150 foot-pounds of torque at 3,250 RPM.

I doubt it. According to your photos and time line, it sat and idled for forty minutes without overheating. In the last TWENTY MINUTES the needle barely moved. What makes you believe it would have gone into the red if you had let it go longer?

Who did you order the new flex plates from, what brand are they (if the box shows a brand), and what's the part number? AutoZone shows me a flex plate number FRA-333 for an '88 Cherokee 4.0L. They show the same one for a 1990 MJ. Price is $54.99. For a '92 MJ, they show me part number FRA-480, and the price is $96.99. If all else fails, Crown uses the same part numbers as Jeep, and their stuff is good quality. My dealer supplies Crown where the factory parts are no longer available (which I'm sure is the case for a Renix flex plate). I think my dealer will ship -- call Todd or Rich at 860-274-8834, ext 3. Tell them Harwood suggested them as the miracle workers and see if they can get you hooked up.

The rear shocks for a Comanche are not stud mounts, they are eye (loop) mounts. The studs are on the vehicle. It's the upper end of the fronts that's a stud (stem) mount. Page 4 -- the type on the left is what's on the rear of the MJ: http://www.monroe.com/assets/downloads/english/08_MountingLengthSheet.pdf

Is your ECU located under the dashboard, over the driver's right foot, or under the hood between the air box and the fender? For an '87 MJ (or any Renix) the 33002675 should be the correct part number. Another question: The '87 4.0L and the '90 4.0L were both Renix models. Why did you install the underhood wiring from the donor? All you should have had to install was the TCU and the associated harness for that. Are you certain the '90 donor wasn't a '91? Do you still have it, or a record of the VIN number?

I saw that one. The kid survived, too, but apparently he's in pretty bad condition. Idjit.

Brit video of a race car "off road excursion" at an unnamed race in Colorado. I'm guessing it may be Pike's Peak. Check this out: http://www.telegraph.co.uk/news/worldnews/northamerica/usa/9476338/Race-car-driver-Jeremy-Foley-plunges-off-Colorado-mountain.html OUCH!

What year did Jeep change to the long TC tailshaft extension with the seal on the shaft rather than the yoke? I thought it was 1997, which means that a '96 TC would not be a direct replacement. As to ZJs -- did the ZJ ever come with a 231?

That's not exactly what I wrote. The factory cat is 2-1/2" inlet and 2-1/2" outlet. On the inlet side, the cat has a short pipe that terminates in a 4-bolt flange to mate up with the exhaust pipe. This is an integral part of the cat, unlike the universal style you bought. On the outlet side, the outlet pipe is also an integral part of the cat and there is a step-down from 2-1/2" to 2-1/4" midway between the cat and the muffler -- all integral with the cat. It should look about like this:

Did you install the reinforcing sleeves in the front axle to prevent the Cs from bending the tubes ( which is generally what happens with the JK front axles)? The reinforcements are smaller tubes that are a slip fit or light press fit inside the stock tubes, and are then welded in place to beef everything up. Don't even consider using a JK axle for off-road if you're not planning to do this modification.

The stock system is [2-1/5] [EDIT] 2-1/2 [/EDIT] inches for the exhaust pipe to the catalytic converter, and for the converter itself. The step is between the cat and the muffler -- 2-1/2" out of the cat, 2-1/4" into the muffler. I very much doubt you'll find anything off the shelf in stainless, but most muffler shops can bend a set of 2-1/2" pipes using the factory routing as a template. It was most likely me who recommended Gibson, but I don't know the difference in sound between/among their various system options.

You'll be sorry. It will ride pretty much like you removed the shock absorbers and welded solid rods in their place. I thought you said he was restoring the Bronco. Your (and his) idea of "restore" must be different from mine.

??? My '88 was still getting about 18 MPG last time I checked the mileage. It's a shortbed, so figure 18 gallons time 18 MPG and a tank (if I chose to run it down) would take me about 324 miles.

I understand what you're asking but the question has no valid answer. First, only the shortbed has that tank size, so owners of longbeds are disqualified. Second, no two gas gauges read exactly the same, so if I refill when it hits the 1/4 mark and you refill when it hits the 1/4 mark, it's almost guaranteed that both tanks WON'T take the same amount to fill. Same applies to the warning light -- when it turns on is not scientifically reproducible from one truck to the next.

That's exactly the question, and only you can answer it for you. My view is that they aren't making them any more. I once knew a guy who had owned a 1928 Stutz. He lost it in a divorce, but when he had restored it he made detailed drawings. So he was building a new one -- from scratch. Right down to making his own bolts (because they use a unique, acorn-shaped head). If you have the skills and the equipment, I think you should save it. But ... that's easy for me to say, because you're the guy who would be doing the work.

Trying to decode an old XJ or MJ build sheet is impossible. Chrysler "recycled" many of the codes, so if you run a build sheet now the results will be very misleading.