Eagle

What year is your 2.5L? If it's a Chrysler ECU, it does "learn" from driving, but it uses the vehicle battery to store what it learns. Some people plug a 9-volt transistor battery into the cigar lighter to hold that data when the vehicle battery is disconnected. The Renix ECU does not "learn." Every start is a cold boot from the default settings.

What year is your 2.5L? If it's a Chrysler ECU, it does "learn" from driving, but it uses the vehicle battery to store what it learns. Some people plug a 9-volt transistor battery into the cigar lighter to hold that data when the vehicle battery is disconnected. The Renix ECU does not "learn." Every start is a cold boot from the default settings.

I don't know what the problem is, but you definitely have a problem. Half a quart in 40 miles extrapolates to using 31.25 quarts in a 2500 mile oil change interval. Even by Ford standards, that's a mite excessive. Compression check? Leak-down check? What did they use for rings? Is it possible the new rings haven't seated yet? Maybe they didn't hone the cylinder walls correctly?

I don't know what the problem is, but you definitely have a problem. Half a quart in 40 miles extrapolates to using 31.25 quarts in a 2500 mile oil change interval. Even by Ford standards, that's a mite excessive. Compression check? Leak-down check? What did they use for rings? Is it possible the new rings haven't seated yet? Maybe they didn't hone the cylinder walls correctly?

Even with a 401, 10.xx in a Comanche would be tough. I used to race with a guy who had an original 1969 AMX 390 4-speed. It took trick shocks, slicks, headers, and distributor work to break 14 seconds with that car. A Comanche is too light in the rear to ever hook up for a 10-second quarter mile. I'm inclined to agree it must be an eighth mile track.

Even with a 401, 10.xx in a Comanche would be tough. I used to race with a guy who had an original 1969 AMX 390 4-speed. It took trick shocks, slicks, headers, and distributor work to break 14 seconds with that car. A Comanche is too light in the rear to ever hook up for a 10-second quarter mile. I'm inclined to agree it must be an eighth mile track.

It feels like that, if you don't know what's happening. It happened in my '88 XJ about ten years ago. Naturally, it was the coldest part of the winter. I'd be motoring along with the heat on high and the fan on to keep my feet nice and toasty, get to a long upgrade -- and all of a sudden my feet were freezing. Of course, it feels much worse than it is when you've been in a nice warm breeze and all of a sudden -- no more warm air. It's still blowing, but it's pushing the air up to the windshield, and you don't really notice or feel it there when your feet suddenly start icing up. First thing to check is the vacuum tubes in the vicinity of where they run past the battery tray.

It feels like that, if you don't know what's happening. It happened in my '88 XJ about ten years ago. Naturally, it was the coldest part of the winter. I'd be motoring along with the heat on high and the fan on to keep my feet nice and toasty, get to a long upgrade -- and all of a sudden my feet were freezing. Of course, it feels much worse than it is when you've been in a nice warm breeze and all of a sudden -- no more warm air. It's still blowing, but it's pushing the air up to the windshield, and you don't really notice or feel it there when your feet suddenly start icing up. First thing to check is the vacuum tubes in the vicinity of where they run past the battery tray.

usually with a new filter this is normal. one should clean a filter before it is put in with an airbrush or airfilter cleaner. if you can find a K&N setup for an XJ (Cherokee) it will work. maybe try some tuner brands or go onto summitracing maybe jegs No, the problem is that the K&N filter element they sell for the XJ/MJ airbox is 1/4" too short, leaving a gap that allows dust and dirt to bypass the filter. There actually is a K&N element that fits the XJ/MJ 4.0L correctly -- problem is, it's listed for some Dodge vehicle and not for the Jeeps. If you're talking about the air tube/cone filter system that replaces the stock air box, you also have to remember that the K&N system relies on oil to attract dirt to the filter. The filter itself, dry, is not very effective. Having grown up when oil bath air filters were the norm, I think they are a colossal PITA and I want no part of them. The stock air intake system works just fine. We are not running NASCAR race engines that spend all day at 7,500 RPM. You just don't need a freer-flowing intake to loaf down the highway at 2,000 RPM, or crawl rocks at just over idle speed. Save your money for something worthwhile.

usually with a new filter this is normal. one should clean a filter before it is put in with an airbrush or airfilter cleaner. if you can find a K&N setup for an XJ (Cherokee) it will work. maybe try some tuner brands or go onto summitracing maybe jegs No, the problem is that the K&N filter element they sell for the XJ/MJ airbox is 1/4" too short, leaving a gap that allows dust and dirt to bypass the filter. There actually is a K&N element that fits the XJ/MJ 4.0L correctly -- problem is, it's listed for some Dodge vehicle and not for the Jeeps. If you're talking about the air tube/cone filter system that replaces the stock air box, you also have to remember that the K&N system relies on oil to attract dirt to the filter. The filter itself, dry, is not very effective. Having grown up when oil bath air filters were the norm, I think they are a colossal PITA and I want no part of them. The stock air intake system works just fine. We are not running NASCAR race engines that spend all day at 7,500 RPM. You just don't need a freer-flowing intake to loaf down the highway at 2,000 RPM, or crawl rocks at just over idle speed. Save your money for something worthwhile.

^^^ Agreed. The heater isn't "cutting out." It's "redirecting." The flappers that control air flow are operated by vacuum. One of the functions of the vacuum canister (the "football" or the "blimp") behind the right corner of the front bumper is to maintain vacuum when the engine is under load, such as going uphill, so the ventilation controls operate normally. The default position for the vants in the dashboard is the top-of-dash defrost outlets, so when you lose vacuum the air flow switches to those. When the vacuum comes back, the airflow reverts to wherever you had it set for. Either your vacuum reservoir is cracked (or missing), or you have a vacuum leak.

^^^ Agreed. The heater isn't "cutting out." It's "redirecting." The flappers that control air flow are operated by vacuum. One of the functions of the vacuum canister (the "football" or the "blimp") behind the right corner of the front bumper is to maintain vacuum when the engine is under load, such as going uphill, so the ventilation controls operate normally. The default position for the vants in the dashboard is the top-of-dash defrost outlets, so when you lose vacuum the air flow switches to those. When the vacuum comes back, the airflow reverts to wherever you had it set for. Either your vacuum reservoir is cracked (or missing), or you have a vacuum leak.

Dunno how I missed this thread on Monday, but at least I was able to come in when it appears there may be hope on the horizon. Your knowledge of the brand and your dedication are much like that of the parts guru at my local dealership. I really hope this interview goes well for you. Good luck.

My '87 has the roll bar lights. Switch is in the bezel to the left of the steering column and uses the same icon as the fog lights. Mine does not have fogs, so I don't know what they did if you got both.

But he asked about long block. The 2.5L got the TBI starting in 1986, a year before the 4.0L came along, and like the 4.0L went to the Chrysler injection system starting in 1991. So the direct swaps for an '87 would be 1986 thru 1990.

You may indeed have multiple things going on. By all means, start with the thermostat, since the evidence of the hoses is what they call a "clue." The other thing to look for is if it heats up quickly when you're stopped, and then cools back down toward normal as soon as you get rolling again. That indicates that the viscous fan coupling on the mechanical fan isn't doing the job, and at rest the fan isn't pulling enough air through the radiator to cool the system. Once you're rolling, vehicle motion forces air through the radiator, so the temp drops back down.

First, how much sag is there, and how are you measuring it? Best approach if you really have sag is to get another set of XJ springs, cut the eyes off the main leaves, and use them as add-a-leaves. I did that on an '88 XJ I was refurbishing for an ex-GF. The rear had sagged a half inch (measured from axle centerline to flares). The addition of a pair of cut-off main leaves gave me a gross lift of 1-1/4". Because I had started out a half inch low, the net gain was a 3/4" lift over stock height -- which is less than the factory Up Country option. The ride was very good. Short AALs that try for a lot of lift are very choppy and harsh, but I've met several people who have used cut-off main leaves as an AAL and all agreed that the resulting ride was very comfortable.

I can't imagine why anyone would prefer digital instruments over analog. Especially for the speedo and important gauges like temperature and oil pressure. With a digital readout, you actually have to take the time to read it to know if you're in the safe or normal zone. With analog instruments, once you have driven the vehicle for awhile you brain knows where the needle is supposed to be. All you have to do is glance at it. If the needle is in the normal position ... that's all the input that's necessary and the brain just says, "Okay, look att he road, Dummy." If the needle is NOT in the normal position, the brain then says. "Hey, we might have a problem here. Better check it out." Digital instruments, in automobiles or in aircraft, are a non-solution to a non-existent problem. They don't accomplish anything an analog dial doesn't accomplish, and they create a more dangerous operating environment.

Oh yes I do.

10-4. That's why I don't have ABS even on the newer Cherokees, when it was available at the time I bought them. If I had known I was going to remarry and turn the 2000 XJ Classic over to my wife, I would have ordered it with ABS. But ... it's configured the way I wanted it for me (except it has automatic, since the 5-speed wasn't offered in the Classic).

More than likely, you'll open it up and find that when your son tried to force it, one of the forks jumped over a slot and got stuck. I doubt anything is broken -- you'll just need to realign everything correctly for neatral and button it up again.

Um ... your signature says you have an 87 and an 89, but your post is asking about an open cooling system. Have you converted, or do you have the terminology mixed up?

Personally I hate ABS, but I wish I had it for my wife. However, especially in a pickup, the rear is what's probably going to lock up first. IF I were going to put ABS on only one end of a pickup, I'd put it on the rear rather than the front.

Correction - it includes some of our 4.0L engines. The Renix system has a knock sensor. Chrysler deleted the knock sensor when they changed over to a Mopar injection/ignition system in model year 1991. No XJ or MJ 1991 or newer has a knock sensor.

As a few of you already know, while I am a life/charter member of NAXJA, I have had my differences with them and I much prefer to hang around on this site. However, I feel I have to respond to this comment. NAXJA was never EVER conceived of as or intended to be a totally freebie web site. NAXJA from its very inception was a "club," with dues and "memberships." And membership expired if you didn't pay your dues. The web site and forum were not the sum total of NAXJA, they were only an adjunct. I was on the board of directors at a time when there was considerable discussion over whether everything on the site should be equally available to everyone. The opinions were far from unanimous, but the consensus was that it was not at all fair for a relatively small percentage of the people using the site to carry the entire cost of operating the site. That was when someone came up with the idea of putting some of the more in-depth technical stuff in a members-only area. I don't remember if the board vote on that was unanimous, but the proposal passed and was implemented. I think that's what you're complaining about. IMHO, the complaint is invalid. Sure, it's nice to have FREE access to the most extensive technical information available, but somebody has to pay for hosting and administering the site. I don't know how they do it now, but when I was on the board NAXJA not only paid a hosting fee, they also paid someone to do the administration. On this site, Pete pays the hosting fee and Pete handles the admin work out of the kindness of his heart. That's great, and I hope it doesn't change ... but we have no right to expect that someone will always make this great site available to us for free. NAXJA's decision to limit access to some of the technical archives to dues-paying members only was not undertaken to make a "profit." NAXJA is a non-profit organization, and unless things have changed since I was on the board nobody draws a salary (except maybe the web admin). The decision was a conscientious attempt to balance access against cost, and to find a balance that was fair to both the dues-paying members and to the hangers-on.