135Boom

the fuel filter just got replaced a couple months ago, less than 1k miles with a NAPA gold. I havent messed with the fuel regulator. How do I do the pressure test? Right off that pressure bleeder on the rail? What do I use and what am I looking for? Its weird, cause the pump hasnt made those awful sounds sense....but it also hasnt been that hot sense either. I do get that stumble after the engine is hot though (about 200) when punching it. And it shouldnt be ANY sensor, cause they are all brand new, and the tps is tuned .8/5.0. Runs perfect cold and warming up!

awesome! Well, not awesome....but thanks guys. Yeah, this is still plenty scary...feels like the wheel is coming off on the left side after hitting a bump. I'll check all that stuff. Thanks again guys! :cheers:

......SO, at about 55-65mph I hit a bump or a rutt in the road and it starts the "death wobble" and gets worst and worst unless I let up on the gas and let it calm down at about 50? Is that really "death wobble".....its pretty damn bad, haha. What would be causing that if it gets started after hitting a bump or rutt? Smooth pavement I can 80 85mph no prob....and most the time it doesnt do this horrible wobble ever...just now an then. tires/wheels just got balanced....I have one rear tire that I know is not round and I get a little vibration from... Thank you! ....I'm new to a lot of this stuff, and have been searching my butt off about things...learning a lot now...but it seemed like the "death wobble" was all the time after 45mph and with both tires. Mine is just the front right and its a greater speeds, and I just have to let off a little to get it to go away???

while searching, its becoming apparent that I mihgt have a problem finding a complete setup (sending unit/pump). But I CAN get just the pump? Its working right now and everything, but getting the feeling it won't be much longer if it keeps that up!

Yeah, I really do think it has something to do with your IAC one way or another. Just FYI, I have now replaced every single renix sensor in the MJ. The MAP, MAT, CTS, O2, CPS, Knock, EGR, IAC and TPS ...pretty much everything from that site the guy posted with all the sensors and what their function is. I know you picked up a CTS recently and just wanted to let you know if you have not had the pleasure of putting it in yet..DO IT FROM THE TOP of the motor...not beneath. Just yank your airbox out and you can get to it much easier and actually see the darn thing!.....and you won't get a nice douche of coolant when you get it out, like you would if you were doing it from the ground :)

Hey there. Was out Turkey hunting this weekend and my fuel pump was getting really loud, like it was straining. Truck still ran fine, thank god....but I am wondering what the first indications are that a fuel pump is about to go bad. Take the normal pump noise and easily double it. Sounds deeper, and that is why I say it sounded like it was straining. Truck was hot, cause a lot of 4x4....I noticed once it had cooled down overnight it didnt do it anymore? Trying to keep this thing reliable though, and wasnt sure about this and what others had experienced with fuel pumps going out. My only other recent development is a stumble at acceleration at 3/4 to full throttle. I read that this could also be due to fuel pump problems. Its not ANY sensor in the truck, cause they are all brand new. Just got done replacing every single one in the sucker, haha! and tuned the TPS. Putting in the ford 4-hole injectors this week.............might be putting a fuel pump in now too?

Hey, don't worry about it. I thought the same exact thing. I was like, what diff does it make? haha. Installing mine this week.

don't mean to hijack....but its kind a the same topic. Who makes nerf bars for the MJ?

just bought the injectors. Lookin forward to seeing how they perform, and just how bad my stock ones that are 18 years old and have 187k on them are!!!

cool, yeah, I tried a set from a 91 cherokee and they didnt fit....different floor I guess. Same damn seat it seems like though? If you have some for an MJ that are gray I'll buy them off you. Ive been lookin around for a while now. MJ's are hard to come by in the junk yard around here.

I think the MAP plugs in on the firewall, just like that site shows, but I think the sensor itself is in the top of the manifold, just like the mat sensor. I thought I saw both of them the other day toward the back on top of the intake manifold

Are there suppose to be plastic kick panels/covers covering the bottom parts of the bucket seats...like the metal brackets and such? I am missing those I think....??

yeah, you'll have to be Johnny on the spot with the new one, which is going to be really hard to do with the way that sensor is tucked up in there. I'd just expect to have some coolant loss, and be ready with the new one asap! Let me know cause I am picking up the MAP, MAT and CTS after work....that will complete every vital sensor there is in the truck for me! The MAP and MAT are right next to eachother on top of the motor, right? I swear that sticking at high idle like you describe, and like what I had is your IAC sticking, cause its only once a week, just like mine was. If there was a vacuum leak, it wouldnt be intermittent it would always leak. I also, just FYI tuned my TPS last night and that helped with drivability and smoothness. Shouldnt have anything to do with the problem, just thought I would let you know that too as we both seem to be on the quest of replacing sensors! haha....and the TPS is sensitive. Gotta be 5 volt supply w ignition on, and .8 at idle. Mine read, AFTER tuning 4.99 and .80

My buddies 90 4.0 does the same thing. Starts and goes immediately to 2k for maybe a split second, and settles right down to a nice smooth 750 rpm idle. Is it normal, I don't know? I guess if its not, and both of our rigs do it, we have the same problem..haha. I don't think its out of the ordinary myself. Truck idles and runs great the way it is. Doesnt do that high idle crap anymore when it would rev to 3k and get stuck there!

how was getting to the CTS for ya. seems like a pain to get up in there! My truck is still going strong. Took it turkey hunting this weekend and have started the thing a TON of times. It hasnt acted up once. Once again, I think the new NAPA IAC did the the trick for me with the spontaneous high idle. That was the last thing I did to the truck before fixing the problem. Otherwise I have replaced the EGR, TPS, IAC, CPS, and O2 sensor....and fixed the backward vaccuum lines going to the egr silenoid on the side of the engine compartment. I also have gone from 12-14 mpg to 17.5 mostly highway but with a lot of woods hours in 4x4!! Probably will still replace the MAT, MAP, and CTS for good measure..but the truck is running AWESOME!! The truck does start and go to 2k rpm right on initial start up, but doesnt stay there for more than a 1/4 second, and right down to a steady smooth 750 rpm.

I'm not a big off roader or anything, this is just my hunting truck and I hate the open diff in the rear. Seems like I have to put it in 4x4 for the dumbest things. What is a good way about going to limited in the rear?

I get my parts at napa or autozone. When you can get an IAC for $40 from schucks/checkers, and at autozone and napa they are about $75-$85...you know you are getting what you pay for thats for sure. Napa had several different IAC's and none were half off like at my local schucks...haha

let me know how you get in there to the CTS!!!! I think you are going to have to get at it from the bottom, and there just happens to be a big @$$ brace in the way, you can't see it, just feel....and its close quarters too! Not impossible or anything, just a pain in the butt! Keep us updated!

ok, good luck! I know how frustrating this crap can get. I just decided to start replacing sensors till I solved the problem. Win/Win to me....all these sensors are 18 years old and have 187k on them....they are going to need replacing....plus, I don't want to be up in the woods and have old sensors be the cause of me getting stranded in the middle of no where. I thought for sure it was going to be replacing your IAC, cause what you describe is EXACTLY what happened to me.....unless in a week from now it starts doing it again, haha.

.........SO, I would replace your IAC for sure. I cleaned the piss out of my old one and it wasnt enough. ALSO, make sure you have your EGR silenoid lines correctly routed. Mine were crossed. They are the tiny little vacuum lines underneath your airtube. To find out, go to the drivers side of the engine compartment and there is a little white deal with two orange wires going to it. Behind that there is a vacuum line coming into an electrical egr silenoid...there should be vacuum on the incoming line (electric connector side/ front of vehicle) and no vaccum on the two port exit. Mine was backwards....which will cause improper EGR action from the sounds of it. The high idle deal is the IAC most likely though. REPLACE IT. :)

my bad....what was broken on my truck was the little knock sensor right above the oil pan, but on the block drivers side. The CTS is above that and behind a bracket (pain in the @$$ to get to). SO, I just havent had a knock sensor. MY TRUCK IS FIXED THOUGH!!!!!!! :) I bought a new IAC and it fixed the problem for me. My old one didnt move freely, infact it didnt move at all, haha. Any idea what the sensor is on the PAX side of the tranny, 2 wire. If you take it out it has a little ball bearing on the end?

I am in the exact same boat at you are. I have cleaned the IAC, replaced the EGR cause it wasnt doing so well, replaced the TPS, replaced the oxygen sensor, cleaned the TB....... It is intermittent (doesnt do it all the time) and in fact didnt do it for about a week, and now its back. SO, its not a vacuum leak. What I did find last night was a broken Coolant Temperature Sensor, so I am replacing that. Otherwise, I don't know what to do. I am purchasing a new IAC to see if that will do the trick too. Besides the MAT and MAP, I don't know if I have any sensors to replace, haha.

can't find any vacuum leak. I did however take out and clean it and messed with the TPS...got the idle to settle down for a little bit, then my egr started makin noise and is messed up now....its like its sticking, and when it does, the idle goes way up, or way down. If its not one sensor its another!!!! I'm just going to replace all of them! 18 years old now.

what about on a 4.0? Still the IAC sensor deal? Mine does the exact same thing all the sudden!

wow....thanks for the reply....that would have sucked! Any other people out there doing a nice bore job on the stock TB incase I go that route later? Whats a MAP modifier? Does that relocate the MAP sensor from the intake manifold to somewhere else? Ever find someone else that had something without having to replace the whole intake?