Eagle

If a new booster didn't solve it, and the fluid level isn't going down, the master cylinder is the next likely suspect.

Preventive maintenance refers to "maintaining," not necessarily "replacing." Simple example -- the older XJs and MJs did not have a grease fitting on the upper end of the track bar, where it attaches to the frame. Those track bars typically lasted maybe 75,000 miles. I don't know when they changed, but the replacements, and those on newer XJs, have a grease fitting. The one on my wife's 2000 XJ is over 100,000 miles and just as tight as the day I picked up the vehicle from the dealership. My '88 XJ is still on it's first replacement track bar and the vehicle is now at 287,000 miles. Grease is "preventive maintenance." Replacing a part that doesn't need to be replaced is not.

??? I've never encountered a forum on which you can't go back and edit posts. (Although some do have a time limit, after which editing isn't allowed.)

I have those, and there is not NEARLY enough space. Those of you who haven't actually looked at this joint don't realize that the tab to which the nut is welded has a significant offset. Therein lies much of the problem.

Already have them, but thanks.

Your transmission is most likely an AX-5. The T5 was used as a alternate standard mostly in '84 and '85, when there was no Comanche, only the Cherokee. I have never heard of anyone having a T5 in a Comanche.

Any 1987 through 1991 XJ with Selec-Trac (the NP242 transfer case) did not have a front axle disconnect. And, once gain, the rear flares from a 2-door Cherokee will NOT (repeat ... WILL NOT) fit a Comanche. The Comanche rear wheel arches are both longer and taller than the Cherokee. Engine specs for the 87-90 4.0L are incorrect. There are three (or four) “generations” of the 4.0L engine. The “first generation” was introduced in the 1987 model year. This version used a Renault/Bendix (“Renix”) designed, multi-port fuel injection system. The original 1987 model was rated at 173 horsepower at 4,750 RPM and 220 foot-pounds of torque at 2,000 RPM. The horsepower rating for this version was raised to 177 horsepower at 4,750 RPM and 224 foot-pounds of torque at 2,400 RPM for model years 1988 through 1990. The “second generation” of the 4.0-liter engine was introduced in the 1991 model year. Designated the “HO” version (for “High Output”), this version was equipped with a completely new multi-port injection system of Chrysler design and manufacture. This version eliminated both the knock sensor and the EGR valve from the Renix system. Sources disagree regarding camshaft design. Some sources suggest that the HO version used a new camshaft of “split” design (intake and exhaust lobes having different durations), while other sources indicate that the camshaft remained the same. The result of the various improvements was that this version of the engine was rated at 190 horsepower at 4,750 RPM and 225 foot-pounds of torque at 3,950 RPM. The “third generation” 4.0-liter engine: In 1996 DaimlerChrysler again revised the electronic engine controls, to comply with a Federal mandate to make all vehicles OBD-II compliant. The horsepower rating for the 4.0-liter engine remained unchanged at 190 horsepower at a slightly lower 4,600 RPM, but the torque peak RPM was lowered, to 225 foot-pounds at 3,000 RPM. An additional running change was introduced in the Grand Cherokee in model year 1999 and in the Cherokee for model year 2000: the single ignition coil was eliminated and ignition was handled by a coil rail system, in which each spark plug has a dedicated coil mounted to a rail directly at the spark plugs. This arrangement eliminates the high voltage spark plug wires of older (“conventional”) ignition systems. The author considers this to be a variant of the “third generation.” However, it can be argued that the change is sufficiently significant that the 2000 and 2001 (and 1999 Grand Cherokee) 4.0-liter engine should be considered to be the “fourth generation” of the design. This version produced incrementally more power than the preceding version: 193 horsepower at 4,600 RPM and 231 foot-pounds of torque at 3,000 RPM.

No, the bolt didn't break. The tab on the nut broke. I think Dr. Sawzall is the solution, but without any mangling of the brackets.

You mean cut out part of the axle bracket? That's not a consideration.

I've lost count of how many track bars I've replaced since I bought my first Cherokee new in 1988, but I finally encountered the problem I always expected but never ran into -- trying to remove the axle end bolt to install a new track bar, the tab stabilizing the weld nut inside the axle bracket was so rusty it snapped off. And the but itself is so rusted that it's almost round -- there's not chance of getting a wrench on it. Who has encountered this, and what did you do? Looks to me like a choice between a sawzall and a die grinder with a cutoff wheel, and I'm thinking I'd probably do less damage to the axle and bracket with the sawzall. But I don't know if I can get the blade in there to make the cut. Any suggestions?

Random thought (perhaps fitting for a random problem): This is a complete transplant. Did you move a complete 1999 wiring harness over to the MJ, or were portions (or all) of the wiring harness home-built? Either way, is everything routed EXACTLY the way it was in the donor vehicle? Is there a possibility that you routed some wire associated with the cam sensor or CPS in such a way that it's picking up random inductive interference?

No gas OR spark? That means either you have two unrelated problems at the same time, or possibly that the PCM has bought the farm (but I don't know if the '96 PCM has anything to do with controlling the fuel pump).

Depends on what you want to do. Marvel Mystery Oil is primarily a cleaning agent. It'll help keep the inside of your engine cleaner, but it doesn't make the oil any thicker, stickier, or "oilier." Lucas is a viscosity index improver. It does the same thing as STP -- it makes the oil thicker, stickier, and "oilier." Personally, if I want a thicker oil I buy a heavier weight of oil. I saw what running STP did to a friend's expensive racing engine once. It wasn't pretty.

i learned the speedin issue from my dad when he had a cop gun him before, could my MJ bein stock hight with 235/75/R15s cause it to do 5 over or is that the speedo off from 27 years of never bein touched? Vehicle height has nothing to do with it. Your speedometer is driven by a gear that's turned by the output shaft of the transfer case (or transmission, if you have 2WD). The number of teeth on the speedometer drive gear has to be matched to the tire size and rear axle gear ratio to calibrate the speedometer. It doesn't really have any idea how fast you're going -- it's only reading driveshaft revolutions. So ... put on larger tires, and the vehicle travels farther for each revolution. That means you're going faster than the speedometer thinks you're going. The difference between 225/75-15s and 235/75-15s isn't much. It's about 1 percent. Call it 2 percent to be safe, and that translates to traveling 2 MPH faster than you think at 100 MPH, and 1 MPH faster at 50 MPH. now i'm confused, i know that larger tires "adds" a little bit more of speed by 1MPH or so but how can i figure this whole speedo thing out, i don't know my gears, all i know bout my MJ is it's an 86, it has a 2.8 v6 out of a 93 GMC sonoma (only cause the old motor had a crack in the block), it has a 5 speed tranny, it's 2wd and i have a 7'8" bed (i messured it :D), and i'm rollin on 225/75/R15s and apparently i speed 5MPH when my speedo reads 25 i do 30, Redwolf First off, you NEED to know what your axle ratio is. It's probably 3.73 with the 2.8L V6, but it might be 4.10. But you need to find out. Once you have that, there are charts on the Internet that tell you which speedo drive gear to use for each combination of tire size and axle ratio. The second thing is that you should understand that the wrong speedo gear doesn't make the speedometer read high (or low) by the same amount at all speeds. It's a proportion. The same applies to tires. The difference gets larger as the speed increases. The way I calculate the difference due to tires is the most accurate way there is. Most tire manufacturers publish the number of revolutions per mile for each tire model and size. Comparing those numbers tells you what percentage of difference there is. I don't have access to 1986 specifications, but I'll take a guess that the original tires on your truck were probably 215/75-15s. According to the tire charts I used when I compiled my tire/gear/speed spreadsheet many years ago (I think I used Cooper Discovere tires, but I don't remember), a 215/75-15 turns 754 revolutions per mile. That's all you need at this point. If you know the axle and transmission gear ratios you can calculate (accurately) the engine RPM for any road speed in any gear, but for just comparing the effect of different tire sizes, all you need is the (tire) revolutions per mile. From the same data, I get 730 revolutions per mile for 225/75-15 tires, and 722 revolutions per mile for 235/75-15s. To calculate the percentage of any change, you take the difference between two values, divide the difference by the original value, and multiply by 100. So, to go from 215s to 235s we get: (754 - 722)/754 x 100 = 4.24 percent. So whatever your speedometer should be reading with 215/75 tires, your actual speed will be 4.24 percent faster. At 10 MPH, that's 10.4 MPH. At 30 MPH, it's 31.3 MPH. At 50 MPH, it's 52.1 MPH. The number I threw at you a few posts above was based on starting with 225/75-15 tires. For those, the numbers are: (730 - 722)/730 x 100 = 1.10 percent.

No, they didn't.

i learned the speedin issue from my dad when he had a cop gun him before, could my MJ bein stock hight with 235/75/R15s cause it to do 5 over or is that the speedo off from 27 years of never bein touched? Vehicle height has nothing to do with it. Your speedometer is driven by a gear that's turned by the output shaft of the transfer case (or transmission, if you have 2WD). The number of teeth on the speedometer drive gear has to be matched to the tire size and rear axle gear ratio to calibrate the speedometer. It doesn't really have any idea how fast you're going -- it's only reading driveshaft revolutions. So ... put on larger tires, and the vehicle travels farther for each revolution. That means you're going faster than the speedometer thinks you're going. The difference between 225/75-15s and 235/75-15s isn't much. It's about 1 percent. Call it 2 percent to be safe, and that translates to traveling 2 MPH faster than you think at 100 MPH, and 1 MPH faster at 50 MPH.

Shifting at 2200 RPM is lugging it? Not hardly. With the automatic and stock tires, 2200 RPM is about 68 MPH in overdrive. I don't think comes anywhere near ANY definition of "lugging it."

Correct. The change to the AX-15 was a mid-year change in the 1989 model run. Around the same time was when the C101 firewall wiring harness connector went away.

I beg to differ with you. There is NO American production in-line six cylinder that's more bulletproof than the AMC six that eventually morphed into the 4.0L Jeep engine. Never has been one more bulletproof, and in all probability never will be simply because today everything is "optimized," to the point that there's virtually no reserve strength to provide that "bulletproof-ness" we used to take for granted when I was young and thought I was immortal. Back "in the day" (and I lived in the day when the slant six had its reputation), when everyone else was running Offenhauser engines at Indy, there was one racer who came year after year with a modified I-6 street engine. His name was Barney Navarro, and the engine was NOT a Dodge slant six. It was the AMC (the 232 version, I believe). When I was in the Army I spent a year stationed at Edgewood Arsenal in Maryland. At the time I was driving a Rambler American with the smallest available version of the engine -- 199 cubic inches. One of my good buddies had a Dodge Dart with the famous slant six, and he made the mistake of challenging me to a drag race. So, late one night, we snuck off to a back road in a remote corner of the post where we hoped the MPs didn't patrol regularly, put out a couple of friends as starter and finish line judge, and we duked it out. Turns out we didn't need the finish line judge, because the race wasn't even close. I stomped him. And this wasn't even with the "hot" version of the AMC engine. My little 199 only had a single-barrel carburetor. The more famous 232 had a 2-barrel, and was a LOT faster. I can't imagine putting a slant six in an XJ or MJ. Sacrilege. (Not to mention a horrible waste of time, energy and money.)

No he's not. It's a Renix, not an HO. I have always shifted at 2200 RPM. My '88 XJ (287,000 miles) still gets 20 MPG, and the '88 MJ (125,000 miles) gets 18 to 19 MPG.

A bad or failing oxygen sensor results in poor fuel mileage because the engine is always running rich. Same thing can happen if you run a cold (or no) thermostat, or if the coolant sensor (the one on the side of the block, that sends data to the ECU) is bad.

I was in an Advanced Auto a couple of hours ago and I saw a set of body-side tailgate hinges in the "HELP!" aisle that looked like they could be adapted to work. They were for a Chevy. There are probably others listed in the catalog.

"Turning over" and "cranking" are the same thing -- they refer to the starter motor making the engine rotate. If you mean it started, then you would say it "started." If you mean it coughed and tried to start, but wouldn't, you would say something like it "fired but wouldn't catch and run." It's really difficult to diagnose by remote control when standard terminology isn't used. If you now have a running MJ, good.

Stock 15x7 rims have 5-1/4" backspacing, and are the optimum setup (on stock axles). An 8" rim is 1 inch wider (duh!), so to sit in the same place the wheels would need to have 6-1/4" backspacing. Now take an axle that's 3 inches wider, and that adds 1-1/2" on each side. So to pull the tires back to the stock location, the wheels would now need 6-1/4 + 1/1-2 = 7-3/4" backspacing. If such a critter existed (which I'm sure it doesn't), it would have so much offset that it would eat up wheel bearings due to eccentric loading, and I suspect steering would be rather ... unusual.

We need to see the back face of the circuit board, the part that's against your hand. That's where the potentiometer is located.