thedave360

whats the problem that it causes? Does the temp being too high cause a lean or rich condition or something?

Assuming I don't have such a sweet CAI on mine at the moment, I should be able to do the same thing on the stock intake box...right? Like on the neck where the box transitions to the tube is what I'm thinking.

Nice. I'll try that too. I wanted to do that anyway, thanks for pointing me in the direction of a good writeup.

Interesting. Mine's a 92 so it isn't renix but I'll give it a shot.

Depends on your trucks setup. Motor/trans? More than likely an axle from an XJ will be 3.55 gears Mine is a 92 4.0HO with the Auto. The donor axle I'm looking at is out of an 01 XJ 4.0 2wd auto

I'm considering doing the same thing, swapping the D35 for a C8.25. Is the ratio the same as the stock front axle?

I need some help from the MJ gurus. So far this problem had only plagued me on the trails but it happened to me the other day in traffic. Maybe heat related? I'm not sure. Anyway here's what it does.... After riding around a while, I get on the trails or in traffic (low speed or mostly stopped while idling) everything is fine unless I stop the engine for a couple minutes. When it cranks back up it doesn't want to idle smooth and will hesitate if I give it gas then it'll start suttering. The idle surges sometimes and it'll kill if I don't hit the gas to keep it alive. It will continue to do this unless I either 1) Turn it off and let it cool for 15-20mins or 2) Get up to highway speeds for a few minutes. Other notes on this... -The temp gauge says the engine isn't getting too hot when this happens. The aux fan doesn't even come on so I know its not getting too hot. -The voltage gauge reads low (right around 12) constantly when lights and AC and Aux fan are on. I've measured with a multimeter at the battery cables and its getting high 13's with all of the accessories on. -All sensors, fuel pump, fuel tank, fuel filter, fuel pressure regulator and fuel injectors are less than a year old -All aluminum 3 core radiator, and higher rpm fan clutch -This problems happened before I replaced everything too. Its gotten a little better, but its still a problem. Any advice would be much appreciated!

I replaced the fan clutch with one from a ZJ because its supposed to move more air. I do have a shroud but its missing a section at the bottom. Probably should get a new one.

Ok, I can live with that. So as long as the temp doesn't keep going up when the fan kicks on, I'm good right?

Excellent. That makes me feel much better about replacing it. With the new one, coming home yesterday in the rain, it didn't seem to affect the temp very much. Any thoughts on getting hot enough to trip the Aux fan while idling after a long drive?

Hi! Been a while since I've been on the forums. I've been busy putting my rebuilt motor back in the MJ and putting some break-in miles on it. I have some questions about cooling though. What is considered a "normal" temp range?? 210-220? Lower? Higher? Here's why I'm asking... I had a local shop who sells remanufactured engines re build my 4.0 (long block). I finally got it back in and its been running a bit warm. I'll go drive it for a while (15-20miles) and when I sit and idle for a while, the temp would jump up to about 225-230 and the aux fan would come on. It would take a while to cool down back to about 210 then it would creep back up and just keep cycling like that until I started driving again. When driving at highway speed it would stay well above 210 unless it was raining...then it would drop well below 210. I've got a little less than 1000 miles on it at this point so I've been trying to fix the cooling issues. I started with the easy stuff, doing a chemical flush on the system. This seemed to help but it was still having issues. The coolant that originally came out looked like chocolate milk. I flushed it enough to get to a nice clear green when I drain it now. After doing that, I went to replace the thermostat. Only to find out that I hadn't installed one when I put the front of the motor together :doh: . I got a stock 195degree. That didn't help at all. It now warms up quicker...which is the job of the thermostat. But after it warms up, it doesn't start to cool down until the aux fan comes on. So I started reading forums..... Thats when I decided, it would probably be a good idea to get a new radiator since the original one had that chocolate milk running through it for so long and is probably corroded past the point of no return. And, I might as well get a new fan clutch, since the one I have is as old as the truck (92). So I bought an all aluminum 3 core radiator (and boy is it shiny! :brows: ) along with a brand new zj fan clutch. After an afternoon of squeezing and praying it would all fit, I filled it up and cranked it up. Seemed to work ok. At a cold start, temps get up quick, then I can see when the thermostat opens and the temp gauge drops about 10 degrees really quickly. I go for a drive, it gets to 210 and sticks there while I'm driving. If I stop though, the temp starts to slowly creep up. It takes a while, but eventually, the aux fan comes on to cool it down. When that happens it goes down quickly, then the fan goes off and it slowly creeps back up again. With the new radiator, it holds temp MUCH better while driving, and takes a while to heat up when idling and cools quickly once the fan comes on. Am I missing something? Or is this normal and I'm just being paranoid? Any advice would be helpful. --Additional Info 92 4.0 HO. stock, rebuilt recently. All new sensors including temp. Running "break-in" oil with zinc additive. (to be changed out soon for normal)

Thats sort of what I thought. I just never heard of a pulse air feeder. Aw well, I won't be visiting that particular junk yard again.

so, I went to the junk yard this weekend to pick up a few things among them was a spare ECM. Normally this place charges $25 for computers. They called the ECM for cherokees and comanches a "Pulse Air Feeder" and charged me an extra $10 for it. I asked for an explanation and they pointed to the heatsink fins on the ECM and said its a Pulse air feeder off a Chrysler and its an extra $10. It was cold and I was tired so I gave up arguing and just ate the $10 and went home but its been bothering me ever since. Am I crazy or do these people not know what they're talking about??

Thanks guys! Hopefully I'll finally be able to get the engine back in the truck this weekend. The rest of the truck doesn't look very great as of now. My avatar is how it looked when I bought it. As of now, this is what it looks like Below is the custom back bumper. I had a local shop fab me some heavy duty brackets. Eventually, I'm going to paint it flat black, add a receiver hitch to the back bumper, powder coat the bumpers and rims CAT yellow to match the engine, and a headache rack/rollbar in the bed behind the cab to store the spare tire, gas cans, and jack. I plan to get a winch mounted to a plate so I can plug it in to either one of the front or back hitches. I also plan on doing a snorkel and a dual battery setup.

So, I've been working on rebuilding my 92 4.0. I have a bunch of other pictures, mostly lame ones of the tear down for my reference. I figured I'd post this one as it sits now....ready to get put back in the engine bay. My neighbor has a powder coating shop, so I went a little crazy with Caterpillar Yellow. More to come as the project progresses!

Its a 1992 4.0 Man that would be sweet if you could send me the set!

Been a while since I been on the forums, but I'm in the midst of assembling my engine after having it rebuilt. Unfortunately I've lost most of the bolts for my oil pan and valve cover. I was wondering if anyone knows of a place where I can get a kit of replacements instead of having to find the sizes and then figure out what hardware stores have these things. ARP doesn't have any kits and neither does Jegs or Summit as far as I could find. The dealership wanted $150 for a kit, and since money doesn't grow on trees, I'd like to find something cheaper. Any ideas would be appreciated. Thanks in advance.

No sir, I only use Mobil1 oil filters. I connected a manual gage to it and it reads the same as the electric one in the dash. I haven't checked the compression...but I imagine it isn't good. I drove an identical truck to mine in much better shape with less than half the miles and I could not believe the difference!

it has about 200000 miles and it has crappy oil pressure. I'm running 2qts Lucas and 4qts 40w, and i'm getting less than 20psi at highway speed. I want to rebuild it before it throws a rod or something and cause more damage that i'd have to fix.

Well, its tax refund season and I've managed to convince the wife to let me use some of the funds to rebuild my 4.0 HO in my Comanche. I have a few questions and am looking for advice from people who've done this before. I plan doing everything possible- main cam and rod bearings, oil pump, all the gaskets, refurbished injectors, rings, turn the crank, hone the cylinders. maybe new pistons and rods? Any advice or words of wisdom for getting the engine out of and back in the truck? Any things I should do or should not do? Any good places to get a complete rebuild kit? Is there anything that you wish you would have done while you had the engine out.

I've done exactly what you are talking about. If you're going to bare metal, definitely use the etching primer. I primed my hood with it and painted it. I have had zero rust come through.

-Sending unit is brand new. Where would these "Engine Ground Straps" be?? -I haven't driven it at all since the ride home. I will check out the fuel filter though. I went damn near vertical on the trail a few times...that could have stirred up the tank a bit. -Fuel economy is... nonexistent lol. I get 13ish just driving around. I don't recall off hand what the clearance is on the bearings. I replaced with stock bearings. Man, I'd really hate to have to change those bearings again :headpop:

I WISH I would have done this when I changed my fuel pump. I changed it without dropping the tank and it SUCKED. I would definately recommend removing the tank. Next time my fuel pump goes out I'm going to convert to an external fuel pump. Thats something you might want to look into. But get a real external fuel pump, don't just rig up an internal fuel pump outside the tank.

Ok guys, I would like some advice on what to do. My 92 4.0 HO is having some problems. I have no idea how many miles it has on it, all I know is it is A LOT. Its always had low oil pressure (20psi at hwy speed, 55-60 and 1800ish RPMs), and its always ran a little rough since I bought it in march of 09. About a year ago, I changed the main bearings and the rod bearings. Along with the timing chain, water pump, and oil pump. All that did little to nothing for the oil pressure and performance. (not that I would expect the water pump to inprove oil pressure though) Last week I went on a trail run with some buddies and it did fine, until the ride home. Any time I was accelerating and got near 2500rpm it would start sputtering and hesitating and generally sounding like crap. A guy I know has a 91HO and I drove it the other day, it was SOO much more powerful than mine. Right now I'm running 2quarts of Lucas Oil Treatment and 4 quarts of 40w oil, and I'm still only getting 20psi above 1000rpm when its at operating temp. When its cold, its close to 60psi. From what I've seen on the forums, 20psi isn't considered "optimal". I'm running out of Ideas here. I'd rather not spend gobs of money on a new crate motor. I just don't know what to do anymore with this thing. Please help me out with some leads on what I can do to fix this thing.

Wow, it looks like it spent 24 years in the showroom. Thats crazy!