Coyote

I just checked flowkoolers website and they did change the design. Instead of sheet metal pop riveted to the impeller, it uses a new machined aluminum impeller that looks suspiciously like the Hesco one. The Hesco very well may be a rebranded flowkooler water pump at twice the price.

You're right, I do have an AW4 with the trans cooler built into the radiator. I'm sure that adds heat to the system and helps to contribute to the problem. The new radiator also has a trans cooler built in (supposed to be the same threads). Unfortunately the temp sensor hole for the electrical fan is threaded differently. It's difficult to get a temp sensor with the correct threads that will work with my existing system. The new radiator comes with 3 electric fans, 1 to replace the factory electric aux/a/c fan and 2 to replace the factory clutch fan. I was planning on just plugging that sensor hole in the radiator and using an inline temp housing (and correctly threaded sensor) to control all 3 electric fans (on separate relays). That seems weird that Hesco would sell a high flow water pump and then recommend using a restrictor plate to slow the flow. I've seen stranger things. Lol. My old flowkooler water pump was exactly like you described; sheet metal plate pop riveted to the impellers. It worked very well on my old 91 Cherokee for 12ish years before the Jeep finally died (unrelated to over heat/temp problems). I'm not sure if flow cooler still uses that design, will have to check and see.

Thanks for the tip. I've changed the unit hubs on my 91 Cherokee 4x4, but haven't had to do it on my 96 Cherokee 2x4 yet. I didn't realize that they take the same unit hub. Just crawled under the 96 and seen the plug you are talking about. Not sure how I feel about that, but at least it uses standardized parts so I should be able to get replacement hubs fairly easy. Just better make sure to get that plug when I get the axle/knuckles.

So they only did that dumb design from '87 to '90? Figures Jeep would do something like that. Lol. Finding an '84 to '86 Jeep Comanche or Cherokee is almost impossible around here, but '91 and up are pretty plentiful. Is the '91 + knuckles the same as the pre '87 ones? I've seen the WJ knuckle swapps, but they require larger rims (16" or bigger). I'm trying to stay with the original Eliminator 15" rims. I can get/do the whole '91+ axle swap, was just hoping I could get away with just swapping the knuckles. Coyote

That makes alot of sense. That pressurized plastic tank is a horrible design.

Researching options for a future front brake project. My 88 Comanche 2wd has led a good life, but it's getting time to replace the original front rotors, ball joints and wheel bearings. The 88 2wd uses a weird hub and rotor design instead of the standard '91+ or 4wd set up. If I have to replace all of the worn parts anyways I was look at swapping it over to the newer design with standard/readily available rotors. I put drilled and slotted rotors on my 91 Cherokee and 03 Wrangler and absolutely loved them, but they are not available for the older designed 2wd front end. I'm not debating the stopping power. The original design was perfectly adequate, I just prefer the newer design. With that being said, will 91+ 2wd knuckles fit on an 88 2wd or do I need to swap the entire axle? Coyote

The fan shroud seems to be in good condition, but the mechanical clutch fan is suspect. When the engine is hot the fan can be turned by hand alot easier than I think it should. That's really neither here nor there, I was planning on replacing the mechanical fan with electric fans anyways. Not a fan of clutch fans, I prefer flex fans or electric fans. They seem to flow more air/cool better at low/no speeds....i.e. getting stuck in Atlanta traffic in July. Lol I didn't realize the flowkooler and Hesco water pumps were the same thing.... that's quite a mark up!!!

As it's begining to heat up in Georgia my 1988 Comanche 4.0 is starting to show over heating issues. When I first bought the truck the heater never worked very well. I did a cooling system flush and blew out all sorts of chunky brown stuff. I was fully expecting to have to replace the radiator and heater core at some point. It looks like that day has come. Lol While I'm changing out parts I figured I may as well upgrade and do some preventive maintenance; converting to an open style, replacing mechanical fan with electric fans, changing heater hoses to the newer 97+ style and getting rid of the RENIX tank and heater valve assembly. I'm sure it still has the original water pump and is due for a replacement. Which water pump do you prefer; original ($40), flowkooler ($80) or Hesco ($170)? The original pump seems to do ok in moderate climates, but it's been kind of dicy on hot GA days in my Jeeps. I've used the flowkooler on my 91 Cherokee and was happy with it, but have no experience with the Hesco one. Is it worth the extra money? I'm in Georgia and it gets retarded hot and humid here during the summer. I don't mind paying the extra money to do this right the first time, but if the Hesco doesn't actually cool any better I'd rather put the money towards other upgrades. Coyote

You're reading my mind. Lol Rear breaks are crap; bad driver's side wheel cylinder, badly rusted drums and break hardware. I'd like to do a rear disc conversion, but for the price I may as well just get a whole new axle with discs already on it. Looking hard at an Explorer 8.8 or Liberty 8.25, don't think an XJ 8.25 is worth it after I add in the cost to convert to disc. Do you prefer the Explorer 8.8 or Liberty 8.25?

I'm just running the stock Dana 35 with 3.55 gears. What are you running? It's all about the low end torque. The 0 to 60 and 60 to 0 times are way more important to me than top speed. I'm never going to road race a Porsche, but I'd love to smoke one off the line. 😂

Swapped out my 1988 ECU for a 1990 ECU per a youtube video/Cruiser54. Getting the top bolt out is a bear, but after that it's a piece of cake. The throttle response is MUCH better. Just got around to doing some 0 to 60 times. I have no way of measuring the horse power, but it improved my time by a half second. Now I'm down to 7.77 seconds. Definitely worth the $135. 😁

The Comanches were considered fast back in the day, but a lot has changed in the last 30 years. I picked up a REM unit and have been having alot of fun with it. Recently I started playing with the 0 to 60 timer function. As I've fixed and modified the Comanche I've been checking my progress with the timer. It may not be the best, but since I don't have a dyno or 1/4 mile track it's the only real consistent way I have of measuring improvements. When I first got my Eliminator it was doing a leasurly 10 sec 0 to 60 (pretty much factory spec). Now after some improvements I'm down to a blistering fast 8.27 seconds. Lol I have no illusions of ever beating a sports car, but what is a realistic expectation of 0 to 60 times without doing any major engine work? Does anyone else care to share their times so I can get an idea of how I'm doing? Coyote

Thanks. I'm slow by today's standards, but back in the late '80s these trucks were pretty sporty. They even set a speed record with one. Lol

Success!!! Got the oil adapter put back in and took it for a ride. 1-2 and 3 work as they should. D shifts like it's supposed to and the REM is reading all the gears/locked torque converter. It wasn't the cause of the problem, but the new solenoids make the shifts silky smooth. I even got my best 0-60 time; a blistering fast 8.27 seconds. Lol Thanks for all of the help I really appreciate it and so does the Comanche. Terry

Not sure what's up with the TCU plug. Maybe I didn't get it cleaned or reseated good the first time and the second cleaning/reseating did the trick? At any rate it's working so I'll go with it. Lol The NSS causing issues makes sense to me. I've adjusted/replaced NSSs in Jeeps before, but this one seems to be real touchy. Very little adjustment between starting in park, starting in neutral and reverse lights working. If it wasn't locked down tight I could see it getting bumped out of adjustment while moving the shifter. I'll definitely keep an eye on it and check that first if any more shifting issues come up. BTW it was a cheap ($20) NSS off of Amazon, I have no idea what brand it is. Do you have a preferred brand/more reliable NSS that you like? Just keeping it in mind in case I need to swap it out. Terry

Pulled the knee panel, disconnected the TCU plug and started checking wires according to the diagram. Every checked good, multiple hots at the plug and good ground. Plugged it back into the TCU and noticed my REM was now displayed 1st gear. I already cleaned and reseated that plug earlier, but I guess it just needed to be done again. Giggled all the connections to make sure there wasn't a short some where. Put everything back together and double checked the REM, everything is still good. 😁 BTW if you pull the 7.5 trans fuse in the fuse block it doesn't seem to do anything, but if you pull the 10 inline trans fuse it kicks it to 2nd locked torque converter. Still haven't put the oil adapter back in so I can't drive it yet, but the REM gear display makes me feel a whole lot better about it. Thank you for all of the help. BTW I attempted to remove the ECU to reseat the plugs. The bottom 2 bolts are easy, but that top one is a bear for sure. That project will have to wait for another day. Lol Terry

Ohm, the wiring diagrams are great. Just got done reading all of it. Under the transmission part is has a note: " For diagnostic procedures refer to MS 1700 and TRANSMISSION MANUAL". Do you happen to have either or those or know where I can get them? Thank you, Terry

That's awesome!!! I'm downloading and saving this forever. Looks like I'll be checking wires for the next week. Lol

Thanks for the tips. I've cleaned and reseated the connectors for the NSS, Trans connector and TCU, but no luck. It just occurred to me that I checked the trans power at the fuse block and inline fuse (under the passenger knee panel), but not at the TCU itself. Do you have a pin out diagram of the TCU, NSS or trans connector so I can check electrical connections? I'm guessing there's a break or short in the wiring somewhere, just trying to track down where it's at. Terry aka Coyote

I only put the shifter in park, netrual, reverse and drive. Haven't tried it in 1-2 or3 yet. I have the oil adapter out right now, but when I get it back in I'll give that a try. I've cleaned, reseated and adjusted the netrual safety switch (replaced within the last month). It appears to be working correctly and passes the function checks. How do you test the electrical connection (like adjusting the TPS)? Do you know how to test the connector that goes to the tranny/solenoids (don't know the name, but it's the gray one in the pic) or the TCU itself? Since it went from working to not working literally overnight I'd assume it was an electrical issue, but I've been wrong before. 😂

I've only had my 1988 Comanche Eliminator (4.0 RENIX, AW4, 2 wd) for a couple of months. I've done most of Cruser's tips and it was running great. Recently replaced and adjusted the neutral safety switch, changed all fluids (including trans filter and diff fluid), did the C101 cleaning, added/upgraded battery/block/fuel pump grounds. Also installed a RENIX Engine Monitor, that thing is aweaome. The truck was running like a champ. Took it to the car wash and hosed out the engine bay in prep for fixing old adapter leak. Got the fuel pump relay wet and caused a no start until I could get a new/dry relay. As soon as the relay was replaced it fired right up, drive to the house and the rest of the day was uneventful. The next morning when I hopped in it to go to work it fired right up, but the REM showed ??? for gear (was previously working) and I had to rev it to get it to move, kind of like the transmission was slipping. I drove it less than a block and parked it back in the garage. Since then I've checked the power at the 7.5 amp trans fuse in fuse block, 10 amp fuse going to the TCU (under the passenger knee panel), cleaned and reseated the TCU connection, cleaned/reseated/double checked all engine bay connections, replaced all engine bay relays and added the dash/knee panel ground. My last attempt was replacing the transmission solenoids (all 3). None of that has helped, the REM still shows ??? for gear and the trans still acts like it's slipping. Any suggestions on what might be causing the problem? Terry aka Coyote

I've never seen an intact rear sliding window. That picture was perfect now I know what the latch is supposed to look like. Looks like I'll be scrounging up a Ford window latch. Thanks for the help. 😁

When I bought my '88 Comanche the factory rear sliding glass was intact, but the latch was missing. I'm trying to find a replacement. There's nothing keeping the rear window shut, nada. I've never seen one, so I'm not even sure exactly what they are supposed to look like. Does anyone have a latch for sale or a source to get one? Terry aka Coyote

Finally got the REM mounted in the center console last night. Thanks for all of the ideas. The tips about rotating the diagnostic port 180 degrees, using a wire loom and feeding it through the plug by the vacuum boost were money. Dzimm's center console mount made it look really clean. Great quality product, fits like a glove and he's a real pleasure to work with. If anyone else wants one of his mounts you can order them here: BTW you can mount the REM with the face plate off so you can remove the REM (like his picture above) or with the face place on (like my picture below). Either way works great, just depends on what look/functionality you are going for.

1988 Jeep Comanche Eliminator Build date (and all other info) is blank on the door sticker. 4.0, AW4, 2 wd Bought Jan 2021 in Monticello FL. It ran and still had the factory Eliminator rims (in bad shape). Currently resides in Kathleen Georgia with me. Used as my daily driver. 😁 REM installed in Dzimm center console EGR valve, factory air box and convoluted vacuum lines replaced with after market open air intake. Injectors upgraded to Bosh 4 hole Braided stainless steel brake lines Headlights and exterior lights converted to LED Interior lights converted to LED (instrument panels and cab lights (they still work)) All fluids replaced with synthetic All sensors replaced (NSS was a PITA) Speedometer cable replaced Bluetooth stereo and speakers It's still a work in progress, but it's reliable enough I use it as my daily driver. It's my fifth Jeep and I love them all. Except for the 1999 Grand Cherokee, you can keep that POS. 😂