AZJeff

That makes sense. It's odd that the later injectors are fed higher nominal pressure than are the older ones, but an aftermarket regulator should give me the pressure I need without resorting to the old vacuum controlled regulator rail.

FSM says the spec. for the MJ pump is 31-39 psi.

So the earlier pump should work with the later injectors no problem. That's good to know. Now does anyone know if the guage sender in a stock MJ tank will work with the late-style XJ gauge? I ask because the late model XJ guage does NOT get it's signal directly from sender. On the late XJ, the sender provides a variable voltage to the ECM, which in turn provides the guage with it's signal. The XJ sender is expected to send 0.6V at "FULL" and up to 8.6V at "EMPTY". What range of voltage comes out of the MJ sender over it's range of sweep?

Sorry for the following novel, but I have to explain why I am asking the questions: The Previous Owner installed a 2001 XJ engine/trans (and instrument panel) into my MJ, and it of course it employs the late model OBD-II engine control system. This system requires a fuel pressure of about 49psi into the fuel rail, which an original MJ fuel pump will not deliver. To achieve this higher pressure, apparently the P.O. chose to use the late model combination fuel pump/pressure regulator/fuel sender from an XJ. SInce this assembly won't fit into a standard metal MJ tank, so he installed some unknown plastic Mopar tank from some OTHER vehicle, which is capable of taking the late XJ pump assy. This all sounds good, right? It runs great....just don't look under the vehicle at the fuel tank, because it's RUBBING on the DRIVESHAFT!! Worse yet, there is no way this tank can be moved over to make clearance to avoid this rubbing. The tank has GOT to go. So....I want to figure out how to use a more suitable fuel tank that will still allow some sort of fuel pump of higher pressure and the sender from the XJ type assembly. I am pretty sure that some others have done this, but I am looking for some advice of what is the best route to take here.

Thanks for the added info, guys

The column from a Cherokee of similar years will fit just fine, and most XJ's had floor shift, even as an automatic. When you scoop up the column, you can also get the console and the floor shift assembly at the same time. Cherokee buckets will also work, but you might need to do a bit of adapting to the floorpan. The only problem I see is that a seat that old might be in rough shape. Depending on your budget, a new seat intended for XJ's might be the best (most comfortable, best looking) choice.

Starters on 4.0 engines don't need shimming. When you had the new flex plate installed, I hope the installer inspected the attaching bolts for damage from the previous cracked flex plate, and he also used Loctite and a torque wrench when he installed the. You might take the dust cover off of the bell housing and do some visual inspection with a flashlight and a small mirror.

When I used to frequent the XJ forums, the general consensus at the time was that the only real reliable fuel pump for the XJ was the Chrysler OEM one. All the others (Airtex, Bosch, Carter, etc.) had a nasty habit of dyeing an early death. That consensus was also 4+ years ago. What does anyone have to say about fuel pumps for MJ's? Are any non-OEM ones worth their salt?

This should do the trick for you: http://gojeep.willyshotrod.com/HowtoD30AxlesSeals.htm

The 4.0 engine has a fuel pump ballast resistor that is mounted on the firewall just below the cowl. This resistor is designed to drop the voltage to the fuel pump, but ONLY does it when the key is in the "RUN" position. When the key is in the "START" position, power to the fuel pump is sent via a different path. It sounds like your fuel pump is only running when the key is in the "START" position, and that is a sign of a failed ballast resistor.

They worked OK on my XJ, but I will admit they need to be adjusted VERY carefully. Even then, I would not trust them to be the only thing holding the vehicle on a serious incline. That's what "Park" is for, or putting it in gear with the engine off. To be honest, even the conventional parking brake on the Bendix-type drum brakes isn't the greatest, as it tends to work better against forward rotation than it does backward movement.

I agree with Eagle. If you are on a limited budget, a lift of NO MORE than 2 inches is still both functional and practical. It won't break the bank, and it won't create some sort of mechanical monster that has bad handling and road manners. Welcome to the club. We are all glad to help!

I tend to agree.

It should work just fine. But..... For most applications, a mechanical parking brake should work fine. The idea of a mech. brake is that it is used for added 'locking' of the vehicle once it's not moving. That works well under two conditions: (1)the brake is not left applied partially and you drive off, dragging the brake and burning up the parking brake shoes. and (2) the parking brake does not freeze "on" in certain climates because of water in the parking brake turning into ice during an overnight parking situation. (This happened to me on a 1961 Ford when I was a kid, and it sucked.) If you have properly adjusted parking brake components that are adjusted, and the cables are lubricated and adjusted properly, the mech. parking brake does just fine. Deleting it is more a case of a personal experiment, rather than necessity of improving a deficiency. Just my $0.02...

Duh...that makes so much sense I don't know why I did not think of that. THANKS!

The best radiator I have ever used in an XJ/MJ was one from Dirks' Off Road. It's not cheap, but it works VERY well. Here in AZ, a radiator gets tested to the max., and I will say that the ones Dirk's offers are top notch in both quality and their functional performance under EXTREME conditions. https://www.dpgoffroad.com/product/csf-hd-3-row-radiator-jeep-cherokee-91-01-open-system/

OK, I am a dumbass on some things. I assume you mean measure the overall extended length of the existing shock, correct? I can do that, but many of the standard "Jeep Parts Websites" don't sort shocks by overall length, and instead list them by vehicle application. I found some Fox brand shocks that match those that should be used for a 4" lift MJ, but I am getting a butt-cramp spending $135 a pop for those.

OK guys, I am still learing about some of the idiosyncracies of the MJ. Now it's the rear shocks. I know they are different than those on the XJ, so where do I search to find a decent set for the MJ rear axle with a 4" lift?

My Comanche lost it's spare tire and the winch that attaches it some time in the past. I am pretty sure that an OEM winch is rarer than hen's teeth. I want to store my spare under the vehicle, so I have the maximum bed space available for carrrying junk. What do you guys recommend for an alternative? Can winches from other vehicles be adapted relatively easily? I don't mind making a few brackets and whatnot.....

If you take the Jeep out on the highway (where you can keep a sustained speed of 40+ MPH, and the engine stays at an acceptable temp, then you can dismiss any issues related to airflow over the radiator, as at that speed, any fans are not needed. That would be a quick test. Just revving the engine up to higher speed for a few minutes won't demonstrate cooling system function correctly, as it takes time for the engine to generate the added heat of higher RPM, and it's takes time for the coolant to absorb that heat and then attempt to transfer it to the air via the radiator. You need a sustained higher engine speed to demonstrate proper water flow conditions. The fact that the engine heats up and cannot dump the heat at higher STEADY RPM makes me inclined to agree with most of the other posters---you are not getting proper water circulation.

You say "temps drop at high RPM's" What exactly does that mean? Is that high RPM's that relate to high(er) road speeds, or just higher engine speed? I ask because the engine will generate more heat at higher revs.

D35 axles have their bearing rollers ride directly on the axle shaft, and the axle functions as the "inner race" for the bearing. The outer race for the bearing is a LIGHT press fit into the bore of the axle housing. A block of wood and a few taps are all that it should take. Anything more than that, and something is wrong. Either the bearing is the wrong size, or something is inhibiting the bearing from seating in the bore of the axle tube. There is a change in bore diameter in the axle tube that acts as a stop to prevent the bearing from being driven too deep. The seal for the axle shaft is a slightly tighter fit into the axle tube. It is coated with a colored sealant on it's outer surface, and thus needs to be driven into the bore of the axle tube with a block of wood and a dead blow mallet until it is FLUSH with the end of the tube. If the seal won't seat flush with the end of the tube, you have not got the bearing seated into the axle tube sufficiently. By the way, check the surface on the axle shaft where the bearing rollers ride. If the shaft is scored, heat damaged, or exhibits spalling, the shaft must be replaced, or the axle will trash the new bearing in short order.

I am new to this forum, but I have been working on cars for 40+ years, and XJ's for 15+ years, so I know the needs of the XJ/MJ community. The old tubular 3-legged jackstands are not the most durable, and can fail pretty dramatically if they welds on the small cross-straps at the bottom give way. There are LOTS of more modern four legged jackstands out there that will do the trick. I recommend "over-buying" to some degree. For example, an MJ is well under 2 tons, but a 3 ton jackstand is what I would choose, since when used in pairs, they will LOTS of design margin over the actual vehicle weight.

That's what I thought. Now all I gotta do is find a swaybar....