Eagle

If you have the heater set to defrost, it still cycles the a/c, to dry out the air it blows at the windshield. Another possibility is alternator load, when the fuel pump kicks in and shuts off.

By "operational rev range" you are referring to the RPM range where the engine is producing maximum torque. Large diesels actually have a much broader torque range than that (it's a characteristic of diesels in general), but the trucks are equipped with multiple gears to keep the engine in the range right at the torque peak. That's what I'm saying also applies to the Jeep 4.0L. Ideally, for towing you would want to keep the engine close to the torque peak, which is 2400 RPM. If you're going to go off the peak, go for more engine speed because at least then your gaining horsepower in exchange for losing torque. When you drop down to 1800 RPM or less, you don't have either torque or horsepower working for you.

You may just need a new radiator pressure cap. The 2.5L has a conventional overflow catch bottle, not a pressurized surge tank like the Renix 4.0Ls. The coolant doesn't circulate through the catch bottle, and once coolant gets to the bottle no heat is added (except if more coolant enters). That means it can't boil in the catch bottle -- but if the temperature is above boiling (212 F) when it hits the catch bottle, it will boil because it's suddenly going from pressurized (at whatever your pressure cap is rated for) to atmospheric pressure. I believe the factory cap is rated to 13 psi, and that raises the boiling point from 212 degrees to somewhere around 240 or 245 degrees. If the pressure cap isn't doing its job, the coolant in the system will boil at a lower temperature, which will cause more of it to expand and to flow out into the catch bottle.

And at the cost of fuel economy.

An 18-wheeler has multiple granny gears to get the loaded rig rolling, and a fat torque curve that picks up at under 1,000 RPM. Big trucks are geared properly from the factory, and have enough gears in the transmission, to allow the driver to keep the RPMs in the fat part of the power band. The OP here is running the wrong gears, never approaching the torque peak on the highway, and then wondering why the engine feels like it doesn't have any power. The answer is simple -- because it doesn't have any power. To my amazement, I couldn't find an actual horsepower/torque graph for the early 4.0L engines anywhere on the Internet. They used to be everywhere, such that I never thought to download and save a copy. Now I'm really sorry. I was able to find one for a '99 version, here: http://www.automobile-catalog.com/wykres_power.php Note that the torque curve on this one is not as flat as for the Renix engines, and the torque peak is up at 3,500 RPM rather than 2,400 RPM. What is common for both, however, is that there's nothing happening below 2,000 RPM. In the graph, if we look at 1,800 RPM (65 MPH on stock tires with stock gearing), the torque is about 240 Newton-Meters (which is about 177 foot-pounds), and the horsepower is a mere 65 (or so) horsepower. I did finally find a copy of an earlier power graph, but it's so small you can't read it. For what it's worth, here it is: The torque curve is the upper, flatter line. The curve from lower left to upper right is the horsepower line. If we take the torque peak at 2,400 RPM, you can see that the curve is increasing up to that point, and becomes (relatively) flat only after 2,400 RPM. And, of course, as with the other curve you can see that below 2,000 RPM there just isn't a lot of horsepower being produced. That's why vehicles have tranmissions with multiple gears -- so you can choose a gear that matches the engine speed and power range to the amount of power needed to get the job done.

Automatics don't have manually (or "pedally") operated clutches. It's easy to slip a clutch and burn it out when trying to get started with a heavy load in tow.

There's a difference between towing capacity and engine performance, and it seems to me that the primary complaint in the original post here was about engine performance. Certainly, the stock 3.07 gear ratio that came from the factory with the 5-speed 4.0L trucks was a bad choice. You say you only want to tow 2,500 to 3,000 pounds, but that's more than the load capacity of even the metric ton option models, and if you get to 3,000 pounds it's nearly double the weight of the truck. You can't double the weight and expect the performance not to take a hit. The torque peak for the '89 4.0L engine was 2,400 RPM. Because of the axle gearing and the overdrive 5th gear, at any normal highway speed you're actually running below the torque peak in 5th gear. Assuming standard-ish tires, 60 MPH in 5th gear is only about 1700 RPM. You don't hit the torque peak in 5th until you're up to 85 MPH. To get the engine turning closer to the torque peak at sane towing speeds, you need to change your gearing. 3.73 would be a good choice, but not available in used axles that will fit the MJ. 4.10 is also a good choice, and was used in XJs and MJs with the 4-cylinder engine.

True. Unfortunately, I'm in one of those situations where I can't afford to live here and I can't afford to move.

Easier said than done, unfortunately. Connecticut hasn't allowed pull-it-yourself junkyards for more than 30 years. The chances of finding an XJ with a 242 that hasn't already been crushed are pretty unlikely.

Great. Awhile back I got a 242 transfer case, but I didn't think about grabbing the linkage or the shift gate because I didn't think they were different. Do you know if the 231 shift gate will work with a 242, or do I need to start hitting the junkyards?

Correct. The lever itself is basically just a lever -- it's a press fit into the multi-function switch. If your lever hasn't broken off, it's probably not the problem.

So did I. That's why I hated the KYBs -- they did just the opposite of what a good shock should for for keeping the tires on the pavement at speed.

I completely forgot about the TJ. My bad.

Check timing and distributor indexing.

I have used only Walker on my XJs and MJs for over twenty years.

For direct fit into an MJ, only an MJ, from 1987 through 1992, with 4.0L automatic and the metric ton or trailer tow package. XJs from 1987 through approximately 1992 (??), with the 4.0L and automatic, and the optional suspension and/or tow package. These will be the correct width, but you'll have to move the spring perches. There are no other vehicles with a Dana 44 axle that's both the correct width and the correct 5x4-1/2" bolt circle.

My brother agrees with you. I don't. At my brother's suggestion, I put a set of KYB Gas-Adjusts on my '88 XJ when it first needed shocks. They were horrible. No control over large bumps and dips, yet extremely harse of small bumps and pavement cracks. I threw them away after less than three months and went to Monroe. More recently, the 2001 XJ I bought (used) for my daughter had KYBs on the front. No difference -- they were about the worst shocks you could imagine. I know KYBs seem to have a following, but IMHO they suck. If you can't afford OME, just buy Monroe.

Usually what the chips do is alter the timing curve to allow more advance. The trade-off is that they require high-test gas to run. This one claims to fit the renix 4.0L but I don't believe it -- and I think you can get the same benefit by running a high-altitude CPS with high-test gas. With the high-altitude CPS, if you choose to run regular gas, the knock sensor will control the timing so you don't damage the engine. And that's why any chip for the Renix won't show any improvement unless you run high-test ... the knock sensor and CPS keep the timing as far advanced as it can go anyway, so the chip can't override it. Save your money, IMHO.

I don't know what to say. As an old song from my heyday said, "The good, they die young. ... I just turned around, and he was gone."

Agreed. The Xtravisions don't have a Eurpean light pattern, they're American, but they work. Same wattage as standard on high beam but higher than standard on low beam. I chose them over the Silverstars because of the rated lamp life -- it's more than double the Silverstars, for less money. Combine the Xtravisions with the harness upgrade and you'll have very decent lighting without breaking the bank.

??? What aftermarket intake and carb? Are you looking at a specific 3.4 that has been modified?

The video played for me but there's no audio.

There's a big difference in shocks, even from the factory. Both of my 2000 XJs (my Sport 5-speed and my late wife's Classic auto) were bought new with the Up Country suspension option. In addition to the heavier/taller springs, I'm pretty certain the Up Country option used better shocks. My wife's XJ is now at around 115,000 miles and still rides very nicely on the original, factory shocks. (The 5-speed has so few miles that it's not worth using it as an example.)

So ... back to the original post. Are you guys still considering the Tiny House concept? As an architect, the concept fascinates me but, as a pack rat, I know it's not for me. But for two people who are certain there are no kids in the future it's a great way to get into affordable housing. All the more if you're handy and can build it yourself. A lot of tiny houses are built on flatbed trailers, but they don't have to be.

I didn't know the WJ was available as a 2WD. I paid extra to get the QuadraDrive option, but I thought with the 4.7L engine the base setup was a 4WD with the 247 transfer case. I forgot to mention that on my '99 WJ electrical gremlins were heavily represented on the list of issues. I didn't have problems with the door locks or windows, but the cruise control would disengage at random. When that happened, it couldn't be re-engaged until I had stopped and shut off the engine. The WJ came standard with a security system -- no separate siren, but it honked the horn if the alarm was triggered. Mine would do that whenever it felt like it. Dealer couldn't figure it out. One day at the shop I had just gone for a ride with the shop foreman driving. We were pulled up in front of one of the service bays, having a 3-way conversation with the shop foreman, the service manager and myself. The horn started honking, and I told them that's what I was talking about. They accused me of pushing the panic button on the remote -- until I pointed out that the shop foreman was holding they keys. They never fixed that problem, either. Yes, there are two computers. The main one, of course, is the PCM (power train control module). That controls both the engine and the transmission. There's a secondary computer that controls the various functions of the overhead console. It used to drive me nuts that the elapsed mileage on the odometer didn't match the elapsed mileage on the overhead console. The dealership just attributed it to the fact they were controlled by different computers. Yeah, fine, but I only had one set of wheels on the ground. Mine was a '99, and an early one at that. 1999 was the first year for the WJ, the first year for the 4.7L engine, and the first year for whatever they called that transmission. I should have known better than to buy a prototype. I thought they had cleared up the problems by the time the 2000 models came out, but maybe not. I have a friend in Greece who had an '01 WJ Overland, and he had a bunch of problems, too.