Eagle

I was always upset that my dealer didn't rtell me about the rack & pinion steering option when I ordered my '88 Cherokee ...

That's the problem, and unfortunately it's inherent to the design of an I-6 engine. With an I-6, the crank throws are spaced at 120 degrees and the power pulses are absolutely uniformly spaced. At higher RPMs, the exhaust is just a uniform flow, there are no real pulses -- and it's pulses that make an exhaust sound good. That's why I gave up on turbo mufflers for the I-6 decades ago and now I just use OEM replacement mufflers. IMHO, to get decent sound out of an I-6 you need to change the cam to a grind with higher lift, shorter duration, and less overlap, so the individual pulses are more "pulses" rather than "flow."

Remove #1 spark plug, stick finger in hole, crank until you feel pressure. Then stop cranking. Doesn't matter if using a timing light. The light is on #1 spark plug. Crank with the light installed, and watch the mark on the vibration damper to see what degree mark it aligns with when the light flashes. #1 plug doesn't fire when #1 is on the exhaust stroke -- at that point #6 is firing.

It didn't go yet. The ZJ isn't mine, it belongs to a good friend from NAXJA days whom I owe several favors. The keadlights in his ZJ are badly sandblasted, and the driver's side was damaged by the original owner and doesn't work. So I got him a pair of replacement lights, but I decided to let him do any breaking involved. He used to work as a tech in a Jeep dealership and he has owned ZJs before (for some inexplicable reason he prefers them to XJs -- go figure), so I took the coward's way out. I'll report back when I hear from him how it went.

Do you have a timing light? If so, hook it up, point it at the vibration damper, and see if the #1 plug is firing at or before TDC. It should actually be a few degrees before, but I don't recall how many. I know the distrubutor isn't adjustable for timing (in theory), but "back in the day" there was a factory tech bulletin on indexing the distributor to correct for incorrect timing.

Not nearly as bad as I envisioned from your description. That roof dent can be hammered out so nobody would ever know it was there. Takes time and patience, but nothing more than a light body hammer. Offer him $100, see what you can settle on. It's worth saving.

But is it TDC on the compression stroke?

Consider what a pair of taillights alone sells for. Of course it's worth getting, if you have a place to put it while you pick it apart. Unfortunately, as much as I'd like to see tham all saved, that one sounds like it might be too far gone, but ... they don't make MJ body parts any more. I'd offer $100 for starters.

You have spark, but do you have spark when and where you need it? Is it possible the previous owner got the distributor in 180 degrees out of phase? That would mean #1 is "firing" when it's at the top of the exhaust stroke rather than the compression stroke.

Anything you can download today will probably not be valid for an MJ, because Chrysler has recycled many of the option codes. To find the original, look inside the drivers door, and under the driver's side of the seat. Those are the two places the factory typically stashed 'em.

Piston hanging up in the caliper? Worn caliper guides?

Look at it another way -- why would we NOT use an MJ?

Be sure to keep the link secret so nobody else can try it out ...

Gibson. Everything else sounds like crap behind an inline 6. http://gibsonperformance.com/

What year vehicle did this cluster come out of? There's a reason for asking. At one time I had a 1984 Cherokee Wagoneer, with full gauges. The small gauges in the '84 did not (by design) return to zero when the ignition was switched off. They stayed at whatever position they were in when you killed the power. The next time you turned on the ignition, all the gauges would return to zero until you started the engine and they then had data to report. That had changed by 1988, but I don't know when the change occurred. I don't remember if the gauges in my '87 go to zero when the ignition is switched off, or not -- and it's not running at the moment, so I can't check it. It's possible that you just have an old-style cluster. Maybe your engine just has good oil pressure.

"... around 40 to 70" is a large range. With the engine at normal operating temperature, what does it read at idle? What does it read on the highway at 60 MPH in overdrive (around 2,000 RPM)? If you're sitting at idle, in neutral, and you blip the throttle -- does the oil pressure show a momentary jump, or does it sit still?

Try the super basic gauge test. Ignition on, but you don't need to start the engine. Remove the wire from the sender and isolate it. The needle should go to 80 (or peg to the right). Then ground the wire to the head or to a bare spot on the chassis. The needle should go to zero (or peg to the left). If it fails either or both of those tests, either you have a bad gauge or there's a problem with the wiring.

Correct.

You don't have to install the tach in the dashboard to test it. You know those two yellow connector blocks on the right side of the engine bay in the Renix years? One of those is a tachometer outlet -- and one is a ground. You can connect an idle tach to the engine, use jumpers to connect the tachometer you want to calibrate to the diagnostic port, and check it that way.

Thanks for the video. That basically confirms what I had read -- that there's a high probability of breaking something when installing the new units. Got my fingers crossed.

Yes, they do help.

Yes, that's correct. The Jeep wheels are "hub-centric." That means the center hole is sized to fit precisely around that raised center section of the hub, to help carry the weight of the vehicle. There are other vehicles using the 5x4.5 pattern wheels that aren't hub-centric. Ford Ranger/Explorer wheels, for example, use the same bolt pattern but don't have the same center hole diameter. Many aftermarket wheels have a larger center hole and aren't hub-centric. Back to your original post: What's your idea of "vintage"? Are you looking for something that, at one time, was OEM on a Comanche, or are you looking for something that looks like it came from the 1930s or 1950s?

But the Jeep 4.0L starts off with 6 quarts. When the parent engines were used in AMC cars, the capacity was only 5 quarts, and the engines routinely lasted 200,000 to 300,000 miles. On dinosaur oil.. Jeep uses a larger/deeper oil pan. How much additional oil do you need?

Has anyone replaced the headlights in a ZJ Grand Cherokee? Not the halogen bulb -- the entire lens/housing assembly. I need to replace both sides on a ZJ. I have the new units, but I've heard tales of breaking them while trying to install them. What's the inside story?

^^^ This. Step one is to verify which set of holes your cross member is mounted to. Step two is to confirm with Rusty whether or not you got the right length arms for that set of holes.