Eagle

The axles can be used -- the front directly, and the rear by relocating the spring perches (although the rear is provbably a Dana 35, there's a possibility it could be a Chrysler 8.25). The engine, tranny and transfer case can all go into an MJ. If you transplant the newer engine as-is, you would have to rewire at least your engine compartment for the newer HO computer, but you can also just adapt the intake manifold to accept the Renix throttle body, use the Renix distributor, and run the HO engine as a Renix.

Either it's getting bad data from some sensor, or it only runs "right" in open loop mode. If it only ran well for the first few miles after a cold start I'd say it was the latter. If it reverts to good every time you start, well JeepcoMJ is correct, the Renix system doesn't "learn" and store anything -- every start begins from the default ECU program. So, some way, somehow it sounds like there's a sensor that isn't sending the right data to the ECU. Don't be lulled into a false sense of security because various sensors have been replaced. There are defective sensors. I just changed out the CPS in my '88 MJ, and after replacing it the truck still won't start. It;s supposed to be putting out 0.5 to 0.8 volts a/c when cranking. It's producing 0.23 volts. I gave up, had it flat-bedded to the dealership, and a week leter they can't figure it out. Don't give up, but try to double-check everything. Have you found the link someone posted recently to an article on how to test ALL the sensors in the Renix system? In your situation, I'd say it is definitely recommended reading. Ah -- found it: http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm

Before you replace the voltmeter in the dash, check the voltage at the battery with a multimeter. The dash gauges are notoriously inaccurate. The one in my '88 XJ reads about 11 volts, but even when the dealership checked it with their scanner it was actually putting out (IIRC) 13.4 volts -- which is just about right.

The battery trick doesn't work on Renix models, either. (That's 86-90 for the 2.5L and 87-90 for the 4.0L). Every start is a "clean boot."

What about the oxygen sensor? I don't know too much about the Renix injection system (remember, folks, the early TBI was a Renix system, too). Is it possible that under normal cruise it isn't reading the exhaust correctly? I don't know if flooring the peddle overrides the O2 sensor to give a richer mix for maximum power, but it's possible. How does it respond when you FIRST fire it up on a cold day? On a cold start, instead of a choke the ECU operates in "open loop mode," ignores most sensor input, and provides a pre-mapped, extra-rich mixture for warm-up. In my '88 XJ 4.0L, the switch to "closed loop mode" takes place about 2 miles down the road after pulling out of my driveway. I have to back up and turn around before heading up the driveway, so figure about 5 minutes (approximately) in open loop mode. Try your MJ that way. Start it first thing in the morning, get on the road immediately, and see if it's running any different in the first couple of minutes. On cold days, I can literally feel the switch take place. The location happens to be a level stretch with a 35 MPH speed limit. I'll be cruising along in 4th gear, right at the speed limit, and I can feel the engine do a little stutter, bump, and then it smooths right out again.

But this is a 2.5L 4-speed, which means it has 3.45 gears rather than the 4.10 gearing used on 2.5s with a 5-speed. I own two of these. The 2.5L mated to 3.54 gears IS "fall on its face slow."

You do not have to buy a new valve cover.

I bought a new radiator for my 88 XJ this spring. I bought it from a professional radiator shop and they charged me (IIRC) $150. You can get about the same price from the chain places, but I prefer going local on a radiator because if it leaks, he can fix it. So this shop you went to wanted $320 for a radiator that probably costs them maybe $100 -- that's a rather steep markup.

Happy Thanksgiving, all you Comanche dudes and dudettes.

That quotation might make more sense if "morale" were spelled correctly. :cheers:

You have it backwards, Mate. Higher octane retards the burn. Knock is caused by premature (or too rapid) detonation, and that's what higher octane helps control. So you want to take a fuel that's already got a higher octane than any commercially available gasoline (more like aviation gas), and then add an octane booster? You'll end up with a fuel that won't burn unless you hit it with a nuke.

:???: Tax? You're in New York. Clayton is in Connecticut. RE is ... somewhere other than New York. WHAT tax is "included"? There's no tax unless the vendor has a physical presence (meaning a store, office or warehouse) in your state.

I guess I have heard that, but I never remember it because I know the newer ones have a 6-lug pattern. IF the old ones have a 5x4-1/2" circle, and IF the exle is a usable width, then you would need to check the spline count and shaft diameter. Remember, the XJ 8.25 axles were 27-spline with the same shaft diameter as a Dana 35 up through 1996. I believe the beefier 29-spline version showed up in the 1997 XJs. The older ones are hardly worth the effort of welding on new spring perches. The housing and tubes are stronger than a Dana 35 but the shafts aren't, plus they are c-clip axles and the D35 through 1988-1/2 was not a c-clip.

Bad guess. :redX: The AW4 is an overdrive tranny, and one of the selector positions covers overdrive. (On the floor shifts it's the 'D' selection with a circle around it -- I don't know what it's marked on the column shifts.) The power-comfort switch basically just changes the shift points. The power setting is easier on the tranny and is the way they came hard-wired after 1990, when Jeep eliminated the switch. To lock out overdrive, move the selector lever to the '3' position.

I have seen some home-made long arms. I won't go on the same trail with them. BAAAAAD ju-ju. I also live right down the road from Clayton's Off-Road, one of the originators of XJ/MJ long arm kits. I have been in his shop and seen how the kits are fabricated. Keep in mind that Clayton himself is, by profession, an industrial engineer. The kits are NOT easy to make, and doing them right requires engineering skills as well as fabrication skills -- I don't know if you are a professional engineer or not, but if not I suggest that for the sake of your wife and kids you leave the engineering to the engineers and not try to booty fab your own.

1) You will probably need a 4WD rear driveshaft. I don't think the 2WD tailshaft is as long as the transfer case in a 4WD truck. Measure before buying. 2) You don't need the control arms with the new axle, because the 2WD uses the exact same control arms as the 4WD vehicles. 3) As to lift, a SOA is going to lift your truck 5 inches higher than it is regardless of what springs are in it. If it's an inch lower than a 4WD now, it'll be an inch lower than a converted 4WD but it'll still be 5 inches higher than where you started. 4) You can run 31s on a stock MJ with no lift. If you only want to run 31x10.50s, I would either keep it at stock height or maybe just do a 2" budget boost using an AAL in the rear and coil spacers in the front. Keep it simple.

How big are the pistons in the 8.8 calipers? It's possible that the stock MJ master cylinder just can't push enough fluid to the rears to move large pistons.

An 89 MJ doesn't have a 4.2, unless a previous owner bastadized it. It should have a 4.0L, but with the earlier AMC/Bendix/Renault (RENIX) injection/ignition system. Physically, the 4.0L block from a 2003 Wrangler is the same. The computer and injection system is all different, so to do the swap you should have all that stuff from the donor vehicle. The transmission from the 89 should mate up with the newer engine okay, but there might be a difference in the pilot bearing (which wouldn't be an issue if you're using an automatic transmission).

Change of plan. Rather than replace the clutch in the '88 4-cyl 4-speed 2WD MJ with a new clutch and then convert it to a 4WD, I've pretty much decide it's not worth the effort considering that the engine has 219,000 miles on it. I have an '87 XJ 4.0L 4WD auto with a little over 100,000 on the engine, so that seems like a more logical swap. Except -- I would sort of like the truck to be a 5-speed. I have three 4.0L 5-speeds (a Peugeot and two AX-15s) that are all 2WD, and all fubar. I do NOT have a functional 4WD 5-speed for a 4.0L ... but I do have a functional AX-5. 1) Does anyone know for sure how weak/strong the AX-5 is compared to a Peugeot? This little truck will be just used on the street, and I am not a high-speed low-drag kind of driver any more. If the AX-5 is even close to as strong as a BA 10/5 I think it would hold up to my driving. 2) Has anyone put an AX-5 next to an AX-15 for comparison? I have plenty of 4.0L bell housings, if the AX-5 will bolt up to them. Does anyone know if this would work?

I think I'll ask the wife for one of those left handed metric screwdrivers for Christmas. A man can't have too many screwdrivers. I didn't notice -- do they also have metric crescent wrenches?

I'm not sure, but I believe the LWB and SWB are the same, but reversed as to which side they go on because one mounts the shocks forward of the axle and the other mounts them to the rear of the axle. They are different from side to side, though (mirror image), so be sure you get the one that matches yours (unless you buy both sides off one vehicle).

It's a bad ground, and the dash indicator lights coming on is the clue. When the parking lights can't get a ground at the socket, they look for a ground anywhere they can find one, and back-feeding through the turn signal circuit is often the available path. Could be a corroded ground connection, or it could be bad sockets themselves.

Another "Aha!" That's a symptom of a bad fan clutch. When you're not moving, the only air through the radiator is pulled through by the fan. If the fan clucth is slipping, it doesn't pull enough air. Once you start moving, vehicle motion pushes air through the radiator. If it heats up at lights and cools back down when you start moving, the first suspect is the fan clutch.

I'm thinking it may have some drawbacks. I assume they are (or will be) functional? A friend of mine recently finished up a total makeover of his old high school coupe. The car is a 1950 Hudson Hornet coupe, to be exact. He thought it would be nice to have the hood louvered, so he sent it off and paid about $500 to have it done. It came out looking great. Except ... it's a show car, and he said any time it gets any rain on it, the rain comes through the louvers and then he has to detal the engine again ... and again ... and again. Plus he needs to waterproof the distributor. Are you seeing where I'm going with this? The TPS on a Jeep injection system doesn't like to get wet ...

Yes, that is what I am saying.