Eagle

Keep in mind that AMC/Jeep/Eagle for a time used the Pontiac Iron Duke 2.5L 4-banger in the Eagle. That has caused a LOT of people to believe absolutely that all Jeep 2.5L engines are the Iron Duke.

Now THAT's a Gladiator! Sounds like you have a great wife and a great friend. Be good to both of them.

2.5L damper ==> J324 2886 4.0L damper ==> 3300 2920 These are from the 1987-1990 Jeep parts manual

I have always read that the Renix 4.0L injectors are 19.x lb/hour. The 746 injectors, at 20.2 lbs, should be close enough that the difference wouldn't show up in practical application. All of which begs the question of whether the flow rates are measured at the same pressure ...

I've considered converting my '88 2.5L to a carburetor. That single injector is pricey, and it's a bit of a kludge of a system. I'm old enough that I had almost 30 years of wrenching under my belt before I encountered my first fuel injected engine, so carburetors are easy peasey for me to tinker with. Much MUCH less work than converting a Renix TBI 2.5L to the Chrysler multi-port system (which is a far superior system). I think the ignition could remain untouched, but it would also be easy to swap in a distributor from an '84 or '85 Cherokee. But I don't think those used points. I think they were transistorized.

I've seen it in action. When the original exhaust in my '88 Cherokee 4.0L went bad, my brother was managing a Speedy Muffler shop. For my birthday he brought it into his shop and installed a 2-1/2" turbo muffler and a 2-1/2" custom-bent exhaust pipe. It sounded ... bleh. It was louder than factory and had an annoying harmonic at highway speed, but aside from that it still sounded like a very old Maine lobster boat. As for performance, I could instantly feel the loss of power in my operating range (which doesn't exceed 2,500 RPM). It's a five speed, so differences are easy to detect by the seat-of-the-pants dyno. And the gas mileage dropped by anywhere from 2 to 4 MPG, depending on whether a tank was mostly highway or mostly local roads. I'm 75 years old and I've been driving since I was 12 (legally since I was 16). This was the only time in my entire life when I couldn't wait for an exhaust system to rust out so I would have a reason to replace it. When the time finally came, I went with an AutoZone OEM replacement, 2-1/4" tailpipe and a Walker OEM replacement muffler. One of the better choices I've made in life.

To whom was this addressed?

Wow! Three tiny little fans, and they claim that it will maximize cooling and increase air flow by 30 percent. Which is ridiculous, since it's the same radiator. It looks to me like that setup will reduce the airflow by at least 30 percent compared to a factory double fan setup.

Your priorities seem to be different from mine. I prefer to tune for the RPM range where my engines "live" most of the time, which is typically at my normal highway cruising RPM. That gives the best fuel economy, and that's where I'm most interested in maximizing performance.

Really? How much time do you spend at 6,000+ RPM?

I wouldn't design different layouts. Make them as a blank panel and let the buyers make their own holes.

The least labor intensive option available (which is pretty redneck) would be to drop the pan and pull the head, remove the pistons, re-hone the bores, put new rings on the pistons and new rod and main bearings, and slap the head back on it. A friend of mine has a Wrangler 2.5L that blew a piston last year (he plows snow with it, and may have worked it a bit too hard). He bought a set of pistons, put rings on them with new rod bearings, didn't touch the main bearings, and buttoned it up. Runs better than it ever did.

Default mode for the Renix ECU in open loop mode is rich, not lean.

The only aftermarket exhaust I have ever heard that sounded good behind an in-line 6-cylinder engine is a Banks. The problem is, Banks is hyper-focused on maximizing flow, so they use a 2-1/2" system and that reduces low-end torque in favor of more flow in an RPM range that 99.9% of Jeeps will never, EVER see. I'm happy with the OEM exhaust but, if I were to go looking for aftermarket, I think I'd start (and end) with Gibson. https://gibsonperformance.com/p-27232-jeep-exhaust-systems.html

The Peugeot BA 10/5 transmission was introduced in the 1987 model year, behind the 4.0L engine. It was not offered in the 1986 model year. Tranny is almost certainly an AX-5. If not that, it would be a T5, but I don't think AMC/Jeep was still using the T5 as an alternate OEM tranny in 1986.

That shop's price for doing a 4.0L swap seems incredibly excessive even if their price includes completely rebuilding the 4.0L engine. But that wasn't your question. The Comanche came out in 1986, with throttle body injection. But AMC Jeep used the exact same engine in the Cherokee in the 1984 and 1985 model years with a carburetor. It was a crappy carburetor, to be sure, but it was a carburetor so you should be able to source an intake manifold from a junkyard. The question is, what carburetor would you use? Some years ago, a lot of Cherokee 2.5L owners seemed to like a Weber carburetor, but I don't recall the exact model.

That truck looks too good to part out. What does the other side look like?

Lowe's or Home Depot. https://www.lowes.com/search?searchTerm=truck+box

Interesting, and I suppose better than nothing ... but basically a lie. There is no 1984-1993 Cherokee factory service manual. That's a scan of the Motor Manual, which is (or was) an independent, aftermarket publisher of service manuals, similar to Chilton's. I used to buy a new Motor Manual every other year back in my AMC days, but they became increasingly expensive while becoming increasingly less accurate in their information, so I finally had to give up. The 1997 FSM does, however, appear to be a scan of an actual factory manual. For the benefit of Comanchejeepgal, go to that link and download the 1988-1990 parts catalog. There are few differences between a 1987 and a 1988 Comanche, and looking through some of the parts listings it appears that this catalog covers 1987, despite the title.

37,009 KB uncompressed, 29,014 KB compressed. Ah, but that would require having a Google account. Google is part of the evil empire, and I choose not to participate. I don't need them keeping track of everything I do online.

I didn't try compressed, I was too tired to think of that. I'll see if I can remember how to use 7-Zip. As to Google Drive -- first, I don't even know what that is so I obviously don't know how to use it. Second, the publication is, I believe, copyrighted, and I don't think I care to tempt fate by putting a copyrighted publication out there for the world to see. [Edit] No joy. The compressed file is still to large to send as an e-mail attachment.

I don't understand the question. If you're looking to reduce the spacer from one inch to a half inch, why would you need longer studs?

Cooling requires air movement through the radiator. The condition you describe (heating up when stopped, colling down when moving) usually indicates that the viscous fan clutch isn't doing its job and turning the fan fast enough to move the amount of air needed for cooling when the vehicle isn't moving. Since you have triple electric fans, I assume you don't have a mechanical fan with (or without) a viscous clutch. But ... The MJ radiator is only wide enough for two fans of the stock size, so if you have three they must be smaller. How many normally run at the same time? Have you verified that they're working? The symptoms suggest that your fans aren't moving the air through the radiator.

Can't send parts manual. File is too big -- I tried two different e-mail services.

I think I can send you a PDF of the parts manual. There's a link on this site -- somewhere -- to the 1988 electrical manual. There are very few changes from '87 to '88, so that should take care of 95% of your electrical needs. I'm afraid I can't help with the service manual, though.