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!