AnotherOldJeepGuy

I cleaned that plug up pretty good. Took out the next one and it looked exactly the same. My plan was to take all of them out one at a time, note if any looked different, clean each one up as good as I could and put them back it, and see if anything changes. Unfortunately the 3rd one I removed the ceramic top broke, so that plan doesn't really work anymore so I'll be getting some new plugs. I am expecting 1 of 2 things to happen, assuming they all look the same: 1. The black plugs were blacken by the driving since the time of "the incident", and just maybe all the things fixed at this point will result in running well once all the black plugs are replaced with clean ones. This will be the lucky outcome. 2. Nothing will change and the problem remains as it was before this exercise and I'll still be down.

It's starting to rain but I pulled the easiest to get to plug before getting wet. I am thinking the experts can maybe make something out of just this one to start with and I'll go further after the rain. I looked in my records and I put in new plugs, rotor, dist and wires back in Jan and at that time Jeep was very happy. I'll note in case it is useful that this plug was not very tight. It wasn't finger only removal loose, but it took almost no effort to "break" it loose.

I have not tried to track down a pressure tester yet but I did the quickest one, pulled the dipstick. I don't particularly smell anything from it. It is slippery but could it be "a little thinner?", I can't really judge that. If I hold the dipstick up horizontally with the wide side vertical the fluid slowly begins to accumulate more on the bottom, nothing drips off, that's about as much as I can say about it.

This is NOT TRUE! It is more complicated but perhaps what I noted this morning is helpful. It IS TRUE that pulling throttle just off resting position doesn't cause a stall, IF THE EGR PLUNGER DOES NOT MOVE. BUT, if the EGR Plunger does move, it still stalls. So back to the issue that the EGR moves sometimes, and sometimes it doesn't, when I rev up RPMs. This perhaps means something to folks that know stuff!!

Crap, another tool I don't have! I'll check to see if any of the local auto parts places loan or rent something to measure vacuum with with a fitting that works at the Schrader. I do still have the ballast resistor, but have been considering replacing it because the ceramic outside is cracked. I expect the resistor is still connected just it's house is cracked. But since I am going to disconnect it maybe I'll go ahead and replace it at that time. The journey continues.... thanks @Gojira94 for all you time yesterday!

So since I witnessed no change when I plugged this line, and that suggested a clue, what does that clue suggest?

Sounds like you have made good progress!

OK, I did the TPS adjustment. It was off by what seems to be only a little, but I don't really know what a little really is. The ref voltage measured at 4.74V so the target output was 3.934V (83%). It initially measured 4.04 (85%) but I got it adjusted to 3.93 bumping to 3.94 occasionally. I don't know how much damage 2% can do. Also, Before I did this I went around again and wiggled hoses, and noted a change when I wiggled the hose to the MAF. When I noticed that I looked and found a crack. It is entirely possible and I think likely that my wiggle is what caused this crack since I have wiggled and looked at this line multiple times and did not see a crack. Either way, I cut out the crack and patched it. So with these 2 things along with everything else done so far the idle is pretty good although still a bit louder than I remember. It might be almost normal but it I feel like it is still shaking a bit. But it's close. And also the stalling I was able to do repeatedly earlier by just slightly moving the throttle at the TB off the resting position, is no longer happening. So improvements are being done. BUT, it still doesn't accelerate smoothly and my guess is the power assist is still not there at low RPM. With the improvements so far I repeated the water test because I know for a fact I found leaks this way and fixed them in the past, I could not induce any change in RPM at all spraying from the top or the bottom. There may still be an exhaust manifold leak but if there is it's out of sight and not something I can hit with water and cause anything to happen. And I can't get it out of my mind that yeah, a bunch of little things have been fixed, but I can't imagine how any of these things fixed so far could have in any way been caused by the acceleration/brake/turn maneuver that I did, it makes no sense to me. Well, the fact that I was able to tighten the manifold bolts slightly (1/4 max but probably not that much) could maybe have been them getting loosened by a jolt, but the rest I just don't see as a result of that, and especially not all of the things at the same time! Which is still a good argument for an issue with the exhaust manifold or gasket that I just can't find. !!

Thanks, I'll look at that and try it out. I replace the TPS about 6 months ago so it's pretty new, but new things fail also.... Will report back after I do this, probable tomorrow morning.

Oh BTW I got a small mirror and was able to confirm the hose is connected at the underside of the EGR transducer. Also noting that the EGR plunger seems to either move when I start it and continue to do so until I shut down and start again, and on the next start it is no longer moving with I bump the throttle at TB. So whether it moves or not seems to be a roll of the dice on any given start up.

OK. Pulled off the hose not running first and nothing wet there. Put it back on and started. Then pulled it off again. I could immediately hear it sucking in air at the hose but didn't hear any change in the engine. Then when I block the hose with my finger I can feel a noticeable vacuum pull on my finger but I still don't hear any difference in the engine. I also noted, unrelated to this FPR test but just before it, if I pull the throttle at the TB very slowly I can pretty much stall the engine as soon as it is away from rest position. But if I pull it a little more quickly so that I pull quickly it past that "just off rest" position quickly I might notice a very small hesitation but it doesn't stall.

I can't 100% rule out a crack, but I have hunted extensively trying to find one and can't. And the shop that did the diag didn't find one either, so it is just difficult at this point to justify the major disassembly that might be beyond my expertise yet. I replaced all of these about 3 months ago, and long before this incident occurred. Was running perfectly after replacing these until the "maneuver" that broke something. Just making sure this is where you want me to pull off the hose (from a pic from a year ago when I was replacing injector seals). I can pull this off while running without spewing gas? The shop "bypassed the EGR" while I looked for a new solenoid. I thought they just disconnect and capped off one hose but it might be that they also disconnected the hose under the transducer, but so far I can't see down there good enough to be sure.

Ah, well then it would appear that this is at least a clue since when I manually pull the throttle and watch, and I am not getting anywhere near WOT when I do this, I should be seeing the plunger move, and the last time I looked it was not moving. I have seen it move, but not always.

If anyone is willing to loan me an REM, drop me a DM....

Got the NOS EGR Vacuum SOLENOID and installed. Some improvement, still not running right. A bit rough, shaky accel rather that smooth. So if there's anyone out there that hasn't had enough of this journey, I have more questions. 1. Should I see the EGR "plunger/shaft" move in and out every time I rev up the engine or just sometimes? It moves sometimes. 2. While I was revving to watch for question 1, I noticed that if I rev it up enough, as soon as I let go I hear a noise [pop]. I don't know for sure what it is, but you if you can listen to this 4s video I captured, and listen just as I let go of the throttle, you can hear it. It this a small backfire? If it is, doesn't this suggest anything in particular. If it isn't, can anyone say what it is? It's a single knock of somekind that seems to be coming from the exhaust manifold as best I can tell. Since my exhaustive searching have not found any vacuum leaks, and I have tightened everything, what else might have been caused by my initial maneuver (does anyone remember all the way back to my OP ) that started all this? Could I have somehow thrown off the timing just enough to let it run, but run choppy?

I assume you looked here? https://comancheclub.com/forum/5-classifieds/ Also hard to find parts sometimes show up on ebay.

I'm with Pete, I'll believe it when I see it [for sale at the dealers]. But I'd love to see a new 2-door pickup. I note that the article says 2-door, but the picture still shows 4-doors, not sure how to interpret that

Ah OK. Hopefully someone with vent windows may share the ultimate solution they have already done . You might post a picture of the vent and show where it is leaking for the rest of us non-vent-window folks to ponder on ... Maybe in that new post .

I don't have vent windows, but would a variant of what I posted with the window stripping work for this?

I'll be watching cause I have this problem on my car with new door seals that are about 1 year old at this point. This doesn't answer your question, but for cabin noise I cleaned out the window frame/guide and put in basic self-stick weather stripping, approx 3/8" thick and 1/4" wide, and it made a huge difference in the cabin noise at speeds over 50 or so. I did this probably 5 years ago and so far it's still in good condition.

The shop that did the diagnostic did repair these two hoses (Cabin Air Control and Heater Control). These were in bad shape but still connected. I really can't believe either of these caused the major problem, cause they have come loose before and I lost control of cabin airflow control, but nothing else happened and the engine ran fine when they were loose. They also replaced the two small hoses that connect at the back of the Air Box. These were also very bad, but again, they have been bad for a while and the engine was running great. The question I have is about what they also did after diagnosing the EGR Solenoid was bad. They didn't have a new Solenoid, so to bandaid this problem they "bypassed" the EGR by pulling the hose indicated below off the EGR Valve and capping off the hose. It does idle now albeit not as smooth as it used to, and I do have cab airflow control, so obviously I did get improved things. My question to the experts is, with the hose to the EGR Valve disconnected and capped off, what should I expect to happen?

Understood. I found a NOS 3300 2298 on eBay and grabbed it. If it doesn't fix anything I'll have a spare.

So the reason I am asking about the EGR delete is that the shop I took it too for diagnosis said the problem is the EGR Vacuum SOLENOID. For my 4.0 MJ it looks like the part is 3300 2298. Given the circumstances that seemed to cause the failure, I can't say I am all the convinced, but, I'm willing to gamble a little. But I don't find this part number at the places around me (AutoZone, Napa, O'Reilly) or at Rock Auto or Summit. So I am assuming if I can't find one and this really is the problem, the other choice is to delete the EGR, but I am wanting to know if I can remove the EGR valve and block it off without having to also remove the intake and exhaust and remove that interconnect to try and fix my problem. One job is way less work than the other and if I CAN fix it with the smaller job, I'll take that option. Alternatively, is there an aftermarket that will replace 3300 2298?

Gotcha. But I'd still like to know if the delete is functional without removing the pipe between is OK or is it a requirement to do both.

Can you install the EGR Delete Kit without removing the small pipe from the exhaust back to the intake, or is it a requirement to do both?