Eagle

Not according to the Comanche FSM.

But were you certain that #1 was a TDC on the firing stroke, and not the exhaust stroke? The lifters have to be on the cam base circle, not on the lobe (lifted). The crankshaft goes around twice for each one revolution of the camshaft, so it's not enough to just align the timing mark -- you have to verify that you're on the compression stroke and not the exhaust stroke. The way you did it is the way the Jeep FSM says to do it -- but you do have to be certain which stroke you're on.

Please describe how you adjusted the valves. You probably do have oil burning off the exhaust manifolds. To adjust the valves, you had the valve covers off. I'm sure some oil dripped onto the manifolds.

I agree. But ... it's not my truck, and it's not my project.

He is. But the bed is an hour away from where the trailer is being built.

But the TBI system was still a Renix system, designed by the same engineers. I don't know, either, but it would not surprise me if it behaved just like it's big brother the 4.0L.

I found the shortbed frame blueprint. It shows the forward and rear spring eye locations, so just add the difference between the SWB and LWB to the dimensions ahead of the forward spring eye and you've got it. Image Not Found

I believe Hornbrod (if not him then someone else) has posted the dimensioned plan view of the longbed frame.

Remember that the center pins for the MJ springs are 3/8" and the XJ are 5/16". Be sure you have a few sharp 3/8" drill bits handy, and a powerful drill.

TURN IN YOUR MAN CARD! You violated the Prime Directive: You believed a guy in a parts store. His explanation is entirely wrong, and makes no sense. Yes, in the old days not all engines had fan clutches, but the fan has always mounted to a flange on the front of whatever supports it. (Traditionally the water pump, sometimes an idler remote from the water pump.) If you think you're going to get a fan with a drive shaft built into it -- guess again.

??? Huh? The fan is a separate part from the fan clutch/viscous drive. http://www.autozone.com/autozone/parts/1988-Jeep-Comanche-4WD/Fan-Clutch/_/N-iugb1Z9pd92 http://shop.advanceautoparts.com/p/flex-a-lite-fanclutch-5555/10318987-P?navigationPath=L1*14922|L2*15019

At the top of the firewall on the passenger side there's a plastic, lozenge-shaped bottle with a cap on it. That's the coolant reservoir. It is also pressurized when running, and serves as an expansion/surge tank. THERE IS NO OVERFLOW ON THE CLOSED SYSTEM. The reservoir should be filled halfway when cold. Look inside and you should see a post with a notch cut in it. Fill to the notch.

I've seen 2.5L XJs with conventional vee belts and with serpentine belts. I know the rotation of the water pump is reversed with the serpentine belt. I always assumed the fan rotation was also reversed, but maybe not. {Edit to add} From the 1986 MJ FSM:

A bad (or marginal) CPS will cause stalling whenever it doesn't send a strong enough signal to the ECU. It is NOT in any way connected to the clutch, so a bad CPS would not routinely cause stalling only when the clutch peddle is depressed, and at no other times.

There's a special bleeding procedure for the MJ with the rear height-sensing valve. Did you follow that, or just bleed each corner like a normal vehicle?

Nope, forward is forward, and the brakes don't know if it's being driven, towed, or pushed. If you can roll it forward without undue resistance, it's not a brake problem. Unfortunately, in that case I have to agree with dasbulliwagen, look at the tranny.

Could it be the CPS overheating? I began having a similar problem with my '88 MJ shortly after I replaced the CPS. It was okay at first, possibly because I replaced it in January. Once the weather warmed up, I would drive for 3 or 4 miles and it would just cut out. If I sat there for 30 to 45 minutes, it would start up and I could drive home. I still haven't repaired it, so I don't know for sure that's the problem. I just parked it until I have time to deal with it.

My first guess is that the rear brakes are seized. The nature of the drum brakes is that they hold better going forward than they do in reverse. If the shoes are rusted and/or the linings swelled, there may be just enough contact for the rear brakes to apply themselves when you try to go forward. Try jacking up the rear wheels and see if you can spin them in the forward direction with the wheels off the ground. If you can't -- then pull the wheels and remove the brake drums and try again.

That's the spec, although it should be GL-3 rather than GL-5, I believe. But I think that's more important in the AX-15. I used 85W-140 for keeping a whiny transmission quiet. I drove it for a couple of years, sold it, and the new owner had no problems for a t least a year. Then we lost contact.

I was getting bored while recuperating from surgery, so to have something to occupy my time I turned to a small project I've been ignoring for a long time. Along the way, I managed to come up with two pairs of MJ rear springs. Both sets are 3+1, so I guess they're standard springs. 2WD or 4WD? Your guess is as good as mine. The only problem was that three out the four springs had broken leaves. But .. not all the same leaf, so I set out to pull individual leaves from the three springs to make up one good spring to make a pair. I got together one overload leaf, one third leaf, one second leaf, and a main leaf. Spent a bunch of time wire brushing and chipping flaked rust off them, then put on two or three coats on Rustoleum semi-gloss black and reassembled. The first thing I discovered when I laid out my finished creation next to the original spring is that the overload leafs are not symmetrical. Y'all may have been aware of that, but I wasn't. So I loosed the center pin nut, spun the overlad leaf around 180 degrees, and tightened it up again. Just stiing out of a vehicle, the free arch of the two spring packs looks pretty close, so I believe if they were put in a vehicle they would probably ride evely. Then I looked closer, and I discovered that the rebound clips (which are riveted to the third leaves in MJ springs) aren't the same height. On the spring I rebuilt, I replaced the bolts through the rebound clips with new 3/8" bolts in new 1/2" steel sleeves. Even with the new sleeve, the cross bolts leave a gap of a quarter inch or more (easily enough to add a leaf) to the top of the mean leaf. The original spring has zero gap. I have one more third leaf, which has the taller rebound clips, so I now plan to disassemble the original spring and swap the third leaf. The question is -- why the difference? The two springs, side-by-side Detail of one end The difference between the rebound clips

Looks very similar to the cap sitting on my '88 MJ right now. Not exactly the same -- mine tapers down more gradually in the front, and the twin vertical windows at the rear are slanted on mine rather than straight vertical. I have no idea who made mine. I bought it used several years ago.

What weight gear oil did you use? I've kept noisy transmissions happy for periods of several years by changing to a heavier weight than specified. It makes shifting a bit difficult on cold mornings but, other than that, there's no penaalty and it keeps the gears and bearings happier.

Definitely NOT a Pioneer if it had idiot lights. Only the base model had idiot lights. Pioneers had all gauges except the tachometer standard, and the tachometer was optional. I would start by finding what part number water pump you installed, and verify that it's the correct water pump for a 4.0L with a serpentine belt. The serpentine belt routing causes the pump to rotate in the opposite direction from a conventional vee belt setup. Because the 4.0L block is basically identical to the older 4.2L, and the 4.2L had vee belts, a 4.2L water pump will bolt on but the blades on the impeller are oriented wrong for the "reverse" rotation with a serpentine belt. Also, be sure the lower radiator hose isn't collapsing. Tat spring is in there for a reason.

It won't hold because that's the design. Try it heading forward down the hill. The drum brakes on the MJ are what used to be called "servo assisted" brakes. The reason for the unequal length shoes and for some of the other hardware inside is to allow the brakes, once applied so the shoes contact the drums, to use the friction to rotate the shoes and jam them tighter against the drums for more stopping power. But ... it only works going forward. That's just the nature of the beast. Part number 12 in yjxj's exploded diagram is NOT the parking brake adjuster. It's the primary brake adjuster, and should be adjusted with the parking brake cables backed off and slack. Adjust the shoes just to the point of slight drag, then back off two clicks on the star wheel. The factory manual says to perform a final adjustment by doing five hard stops when going in reverse. THEN you adjust the parking brake cable. The FSM calls for using a special tool to check the tension in the forward cable, ahead of the splitter. For the rest of us, the brake should be adjusted so that it will hold the vehicle when headed forward on a moderate downgrade (say 5 percent to 7 percent). Don't even try to make it hold when parking headed uphill ... you'll just break (not brake) something.

I can tell you the values for the resistors, but I don't trust my math for figuring out what the voltage should be. Lo = 2.39 Ohms M1 = 0.89 Ohms M2 = 0.34 Ohms Hi = 0 Ohms You should definitely not be getting the same voltage for all the switch positions. The resistors drop the voltage, and it's the voltage getting to the fan that controls speed. You also should not be getting zero volts with the switch in the OFF position, because the fan speed control doesn't have an OFF. The lowest speed is still a speed -- the fan only turns off when the mode selector (Heat/Vent/Hi-Lo) is turned to OFF. I just did a bit of refresher training on basic electrical theory. Amperage figures into the equation, and what I just read suggests that resistors DON'T drop the voltage in a circuit unless there is something else in the circuit that's using power. If I understood that correctly, with just the multi-tester connected but no fan in the circuit, the voltage would always be equal to the battery voltage. Which is consistent with your results. I'm baffled. Your tests appear to suggest that you have power to the fan motor, ground from the fan motor, the fan motor runs when hot-wired -- but it won't run when plugged into the chassis wiring harness. We're obviously missing something here. Do another test for ground. Unplug the motor. Connect your tester to the negative terminal of the body side of the fan connector, and connect the other lead from the tester directly to the negative terminal of the battery. See what the resistance reading is.