Eagle

The 2.5L and the 4.0L used the same temperature sensor, so that's not the problem. First question: What does your gauge actually read once the engine is fully warmed up, and what do you think it should read?

Clogged catalytic converter? Dirty/clogged fuel filter?

It's a tough job, but somebody's gotta do it. The thing is, we're all busy and we all have too many things going on, and it takes three or four times longer to try to decipher a post that's written in poor English with little or no punctuation as it does to read something that's in "standard" English. I realize I'm an olde pharte and a curmudgeon but, after awhile, I just stop trying and I won't read such posts any more. If one of them happens to be one to which I know the answer -- who loses? Not me.

Then why bother swapping clusters? IMHO, a light that pops on is a better (more visible) backup than a duplicate gauge. Post a photo so we can see what you're talking about. Because I like my junk to look semi-original at first glance. I'll post a pic ASAP. What's more "semi-original" than an original factory instrument cluster? If you like your vehicles to look "semi-original," why install aftermarket gauges instead of factory equipment? Respectfully, you're not making any sense.

Search for discussions of "death wobble"

I'm sorry, but after this post I just have to say something. Is your keyboard defective? Doesn't it have a 'G' key? The following words ALL end in the letter 'g'. Is it so difficult to just type the last letter? relyin adjustin timin gettin fillin causin bein gettin

If you were getting good mileage before rebuilding the carb and poor mileage after rebuilding the carb, I'd guess that something in the carburetor got messed up during the rebuild.

Geyser? I don't think I've ever looked into an uncovered master cylinder while someone else stepped on the brakes, but that doesn't sound right. The fluid is supposed to go through the line to the wheels, not geyser up in the reservoir.

Remove the speedometers from both clusters. Install speedometer 'A' in cluster 'B,', install speedometer 'B' in cluster 'A.' The speedometers in the clusters with gauges have a trip odemeter. The speedo in the idiot light cluster doesn't have a trip odometer. So you would lose the opportunity to gain a trip odometer, but you'll keep your original speedometer so no need to change the cable.

Then why bother swapping clusters? IMHO, a light that pops on is a better (more visible) backup than a duplicate gauge. Post a photo so we can see what you're talking about.

I assume you mean 4.10 ratio. The 2.8L V6 was rated at 115 horsepower, not 120, and the rating was probably optimistic. My personal feeling is that you simply shouldn't even consider tires as big as 33" or 35" with the 2.8L, but it depends a bit on how you plan to use it. For trail only, it might be tolerable. For regular street driving, you'll regret it. I'll assume the factory tire size for your vehicle was probably 215/75-15. With 4.10 gears and the 5-speed, at 65 MPH in top gear the engine would be turning at 2512 RPM. 65 MPH in fourth gear would be 3349 RPM. You can't get gears any deeper than 4.88 for the Dana 30, so let's look at 4.88 gears with 35" tires. 65 MPH in top gear would turn the engine at 2375 RPM, and 65 MPH in fourth gear would be 3167 RPM. In other words, your final drive ratio would be higher (lower RPM) than stock gearing. 33" tires would be marginally better. At 65 MPH with 4.88 gears top gear with 33" tires would be 2526 RPM, and fourth gear would be turning 3368 RPM. Basically equal to your factory gearing and tire size. If you leave the stock 4.10 gearing, with 33" tires 65 MPH would be 2122 RPM and fourth gear would be 2829 RPM.

No. And your stock cluster has three idiot lights -- one for temperature, one for oil pressure, and one for voltage/alternator. Which one did you want to keep, and WHY would you want an idiot light instead of knowing what your vehicle is doing?

If the gauge is good and the printed circuit has continuity, then the problem HAS to be in the wiring between the sender and the printed circuit, or in the power feed TO the gauge cluster. But the other gauges (temperature and fuel) work the same way, so if they're giving you readings you have 12 volts to the cluster. Did you check the printed circuit for continuity of the power feed from the wiring connector to the gauge? If you have a multimeter, you can run another check on the sender. The ohm rating is 0 to 88 ohms. According to the FSM, 0 psi should return a reading of 1 ohm, 40 psi should return 46 ohms, and 80 psi should return 87 ohms. So if you put the multimeter on the sender connector and the other probe to ground, you should be reading 0 or 1 ohm with the engine off. Idle is about 25 psi (typically) so by interpolation if you start the engine and let it idle, you should read something like 20 to 25 ohms, and if you rev it to around 2000 RPM (cruising speed) you should get 46 ohms or better.

You could try hot-wiring it. Take a 12-volt wire from any circuit that's switched by the ignition and run that to the positive terminal on the gauge. Run a second wire direct from the negative terminal on the gauge to the sender.

There is also a possibility that the printed circuit on the back of the cluster has been damaged. Shouldn't happen unless you've been working under the dash and maybe slipped with a tool, but it's a possibility.

It could be the wiring between the sender and the cluster, or it could be a bad gauge in the cluster.

I use DOT-5 silicone brake fluid.

Check your wiring. Ignition ON (engine can be running, but does not need to be). 1. Remove wire from sender. Leave it hanging in air and observe gauge. Should be pegged at 80 psi. 2. Ground wire to a known good ground. Observe gauge. Should be pegged at zero psi. If this test fails, you have a broken circuit between the sender and the gauge.

The '88 and newer XJs and MJs have a ballast resistor in the fuel pump circuit. It should be a whte ceramic block about 3 inches long on the innder fender of the driver's side, near the air filter box. The ballast resistor reduces voltage to the fuel pump when running to reduce noise. The starter circuit has a by-pass so the fuel pump gets full voltage when starting. If you get power with the key in START but not in RUN, the ballast resistor may be blown. It can be easily replaced, but it can also be by-passed, either for testing or permanently. (The 87s didn't have it.)

Clogged catalytic converter?

3.73 gears with 31x10.50 tires is exactly the same as stock tires with 3.55 gears. I think 3.73s are the optimum ratio for 325/75 and 30x9.50 tires, but even for 31s IMHO 4.10s are a much better choice. With a 5-speed, the engine will NOT be "buzzing."

They are the same. The reason you see references to both is that the 4WD trucks had both. In the same truck. Remember, the front Dana 30 has a smaller ring gear and a smaller pinion gear than either a D35 or an AMC 20 (since you have an '86, the AMC 20 was the optional, heavy-duty rear axle). Because of the size difference, it isn't possible to make both with exactly the same number of teeth on both gears. So we get "mismatches" to the second decimal: 3.54 / 3.55, 4.10 / 4.11, etc. They came that way from the factory. That slight difference doesn't matter.

Personally I do think it's probably a bad ground at the horn, but that's only because that was the problem with the horn on my '88 MJ. The relay clicks, so you're good to that point. Next test -- get a helper and a test light, unplug the power lead from the horn and probe with a test light, have your helper push the horn button and verify that you have power to the horn. If you get power at the horn, the problem is the horn, or the ground. Run a supplemental ground. If that doesn't fix it, you may need a horn.

IMHO the ONLY single component that can cause both no spark AND no crank is the ignition switch. However ... on an old vehicle, sometimes multiple problems hit at the same time. Have you tried jumping directly from the battery to the starter solenoid to verify that the starter and solenoid are good?

Okay, so you wanted to splice rather than just use a factory plug. Your call -- I didn't see the original. When you spliced, are you certain you matched all the wire colors correctly? Did you solder the splices, or just twist the wires together and wrap with electrical tape? Since you have a plug in the rear harness, pull the plug, identify which wire feeds the rear taillights, and check that wire on the forward (body) connector of the plug to verify whether or not you're getting power that far. If so, you then focus on wiring from the connector back. If not, the problem is forward of the connector.