Eagle

Because the platinum tip breaks off and grenades the piston. And they don't produce any better fuel mileage than standard NGKs, so why spend the extra money?

Why would you want to do that, and what makes you classify those plugs as an "upgrade"?

The heater control are operated by vacuum, and the default position when there's a vacuum leak is defrost. The usual place for the leak is the tube or tubes leading under the battery box to the vacuum canister mounted behind the front bumper on the passenger side (variously referred to as the "softball" if you have the round one or the "blimp" if you have the oblong one).

I'm sure you could take all the latch parts out and weld up the door, but I think it would be a lot easier to get a replacement door from a junkyard. A door from any 4-door Cherokee up to 1996 should fit. You might want to look at WHY to door cracked, though. I have never heard of that happening, and the only reason I can think of is that the hinges must be sagging so the latch is supporting the weight of the door as well as holding it closed.

Okay, that at least proves that the needle on your gauge is free to move, so the consistent low pressure isn't because of a stuck needle. That's useful to know, but it means the problem is more than likely worn bearings.

Why should he swap in a new axle, and why is a non-disco "the way to go for sure? He's doing a 2" budget boost, and the truck is riding on stock tires. Sure, the non-disconnect axle (if he gets one from a late model XJ) will have bigger u-joints, but the shafts themselves will be exactly the same ... not bigger, not "better" in any way. My '88 XJ has 287,000 miles on the original front axle, with disconnect. I've run 30" and 31" tires on it, and wheeled it all over the northeast fro Maine to Rhode Island to the Mohawk Trail (Old Florida Road) in MA when that was still open, and Arizona/New Mexico. No axle problems at all. The only thing I would suggest is to do the disconnect modification to lock it permanently in the connected position. My only 4x4 failure was on city streets in a heavy snow storm, when I couldn't get up a hill because the vacuum fittings on the disconnect had deteriorated and it wouldn't slide over into the connected position.

Yes, but before you start dropping the pan, be sure that's the problem. The oil pressure SHOULD be higher at road speed than at idle, by at least 10 psi or more. It should also read quite a bit higher immediately after a cold start than after it warms up. If yours is reading a constant 20 psi, there may be another explanation. Step one is to verify that the needle on the gauge goes through the full range. Quick, crude test: * Turn key to ON (don't start the engine). Not Accessory - ON. * Remove wire from oil pressure sensor and place it somewhere so it is NOT touching any metal. You now have an open circuit. The needle should go all the way to the right (80 psi) * Ground the sender wire directly to the block. The needle should now swing all the way to the left (zero psi)

'88 Comanches didn't have PCMs. Are you referring to the ECU (Engine Control Unit, a.k.a. computer)? How's the timing?

Little door? The doors, or flappers, control air flow. If the hoses feeding the heater core are not hot, there's no coolant flowing through the heater core and that has nothing to do with doors. The flow valve is vacuum controlled, if you have a vacuum leak perhaps that's not working. Have you checked it?

Why do you think this is a lie? There are some aftermarket rear sliders available that will (sort of) fit a Comanche if you replace the entire window, but the glass for the actual factory slider hasn't been available for years.

At what engine speed are you seeing 20 psi? The factory spec is 13 psi minimum at 650 RPM idle, and 37 to 75 psi above 1300 RPM. Most XJ and MJ engines seem to idle in the 20 to 30 psi range and run about 50 psi at highway speed. If you are seeing 20 psi at idle, you're good to go. If you're seeing 20 psi while moving, when the RPMs are above 1000, that's not normal.

It doesn't matter if he has a lift or not. Centering the steering wheel is done by turning the adjusting sleeve on the drag link. It is NOT done by disconnecting anything.

No, that's not correct. The XJ and MJ used exactly the same engines, and within any range of years and engine options an XJ will be exactly the same as an XJ. I think what you're saying is that you think the 4.0L engine uses a different setup than the 2.5L engine. That may be correct, but I'd be surprised. However, I have not parked a 2.5L next to a 4.0L to compare them that carefully.

You could also be 180 degrees out of time. Remember, the crankshaft goes around twice for every one revolution of the distributor, with each cylinder coming up twice -- once for compression (which is when it fires) and again for exhaust. Let's just say that I know how easy it is to forget that, and set the distributor so it's firing on the exhaust stroke.

That small tube IS the CCV. There is no physical valve, like with a conventional PCV on many other vehicles.

Not exactly. The CCV tube connects directly to the intake manifold. That small tube coming off the rear of the valve cover is the suction tube. The larger tube at the front of the valve cover is the fresh air inlet, which is supposed to bring filtered air into the crankcase to replace what the smaller tube sucks out. What happens is that excessive blowby puts more air (fumes) into the crankcase than the small line can suck out, so the crankcase goes from being a low-pressure, suction chamber to being a pressurized chamber. In addition to oily fumes being sucked through the small tube (until it clogs), they are also forced back through the larger tube, from which they drip oil onto the air filter element. Then the airstream going to the throttle body picks up oil from the filer and that's how it gets to the throttle body. If the blowby isn't too bad, replacing the two lines and cleaning out the baffles in the valve cover may restore normal operation. NAPA has the complete set of CCV tubes for the Renix 4.0L engine -- I don't know if they have them for the 2.5L but they look similar enough that you could probably use 4.0L parts with minor modifications if they don't.

That's a stock Jeep air box, with an Amsoil sticker on it. Nothing to convert. I guess I misread your post in my first response. I thought you wanted to go back from Amsoil oil to conventional. Now I gather you were referring to the air filter. Just go to pep Boys or Advance Auto and buy a Purolator. The filter element in your air box is a stock filter element. It also doesn't look bad at all.

The "Power - Comfort" switch smooths out the shift points in the "Comfort" mode, and results in worse gas mileage because smooth shifting = slipping transmission. After the Renix era, Chrysler dropped the switch and hard-wired the TCU in the "Power" configuration for improved economy and transmission life.

Blowby. You can probably find multiple discussions of fixes using the search. Step one is to check your compression. If you have bad rings and are getting a lot of blowby, you can't fix it short of rebuilding the engine. If the rings aren't too bad, replacing the CCV tubing may alleviate most of it.

Cutting the front coils worked great for my AMC Javelin autocross/hillclimb car.

Amsoil is just a brand of synthetic oil. If you want to "convert" back ... just do an oil change. Just be aware that it it burns synthetic, it's probably going to burn conventional oil worse.

This would be for the 4-cyl (2.5L) ECU?

^^^ This. The factory sold an aftermarket kit that had all the hook brackets, minus the actual bumper bracket. Take 'em apart and you'll have the same thing. In fact, look at the photo of the tow hook kit for the XJ on the Custom 4x4 web site -- their kit is pretty much a clone of the factory add-on kit. Here's what the bumper bracket itself (no tow hook bracketry) should look like:

Just to be contrarian, I disagree completely with previous posts saying the usual cause of death wobble is loose track bar, loose tie rod ends, loose ___. It doesn't work that way. I drove my '88 XJ for an entire winter with a track bar that was so worn out I had over a quarter of a turn of free play at the steering wheel before it actually began to turn the vehicle. Those things being loose can allow death wobble to escalate, but they cannot cause it. The usual cause is wheel balance. Next most usual cause is wheel alignment, typically insufficient caster angle. You have already been advised to have the wheels rebalanced, and I second that. It's ironic that as the balancing equipment gets better, the people doing the work get worse. The result isn't even a wash -- I've gotten better balance jobs in my own garage using a 30-year old J. C. Whitney bubble balancer than some of the expensive and high tech "professional" balance jobs I've had recently from shops with the latest and greatest equipment. Also have the alignment checked, paying particular attention to the caster angle.

Premature rear wheel lockup is a possibility if you just bypass the rear proportioning valve and keep the MJ front distribution block. I can deal with that -- I'm old enough to have grown up decades before they started using proportioning valves, and I'd rather deal with too much rear braking than none. For those who remove the rear proportioning valve and then have problems with rear wheel lockup, THAT's when you look at the Mopar/Wilwood adjustable proportioning valve.