hgeranium

Very nice! I love that bed cover. How's the fitment on it?

For the entire time of driving my MJ, I've consistently gotten between 10-11MPG in the city and 13-14 highway. At the end of June, my fuel filter began to leak, so I replaced it, and my MPG for the next few tanks shot up to 13.5/17.5. I had that MPG for about a month before it came back down to my usual 10-11. I'm wondering if it is purely external factors/driving habits that have caused this I drive pretty conservatively, not a lead foot but not like a grandma. Always have the trans switch on Comfort. It's not running rich, spark plugs confirm that. No major vacuum leaks. I don't run AC or vent air at all. Air filter is new and in good condition. I haven't taken them off to confirm, but the current injectors are yellow so I think they're the Volvo 746's. I do live in a college town, so the timing of the MPG drop also coincided with the 'back-to-school crowd'; since August I've been in a lot more stop-and-go traffic. The heat also turned on for the summer around this time because of all that rain June-July. I am also in the process of replacing all of my steering components (outer tie rods done, still have track bar and inner ends to install), so the alignment is eyeballed good enough to drive, but not professionally set. My alignment has never been correct since I've bought it since the steering components were so worn, but I figure it plays a role regardless. I just wanted to see if I'm missing something. I've seen the long thread of the guy getting the best MPG possible, but I don't have the money or patience to fire off the parts cannon tuning up and optimizing. I know what it's capable of, but didn't want to assume external factors were to blame without some two cents from y'all.

Thank you!!! This worked flawlessly

This thread was very conveniently timed because my expansion tank just busted. Good to hear that the Dorman tank and cap do OK. Going to keep the original style cap as a spare just in case.

Hmmm. I wonder if the guy in the thread I linked mentioned it anecdotally.

Awesome. I'll definitely check out the ZJs next time I'm at the junkyard. Thank you!

"The cruise control in these vehicles will NOT work if you have changed your brake lights to LED." Found at least one of the causes.

https://naxja.org/threads/how-to-test-repair-renix-era-cruise-control.1160060/ Putting this here for myself and future viewers.

Awesome. Thank you so much! May be a dumb question but where would I find that inline fuse? I know of one for sure in the engine bay but making sure that's the right one. I think it's right next to the battery.

How are these taillights doing for you nowadays? I've been considering pulling the trigger but wanted some longer-term owner opinions.

Howdy again everybody! For a good few years, my cruise control hasn't worked. It worked fine when I first got the truck, and randomly stopped working at some point. I'm curious on where to start. The vacuum to the actual CC module is hooked up, although maybe the routing on the vacuum canister itself is messed up? I imagine it could be the turn signal switch, but I do have a brand new one in there. A mechanic installed it back in 2022 so he may have made an error, but I hadn't had CC since before I replaced that part. I at least know he hooked something up wrong because I don't have high beams so it may be worth my time to take the wheel off and check it out regardless.

I’d like to hear more about this HD clutch and 7 blade fan? Where may one procure that? Rockauto only has standard duty clutches sadly

I was doing some thinking and I bet the style of worm clamp pliers with the long flexible line would be perfect for reconnecting the ball end to the ball so space isn’t as much of an issue. Food for thought for any future viewers of this thread.

Very interesting. Another win for Renix

That’s great to know. I used your guidance to tighten up those bolts but didn’t know if there was enough clearance with that shield on there to remove the manifold itself. I was not looking forward to having to mess with the fuel rail. I figure when replacing the gasket itself it’s not too hard to get it set up from below as well?

Holy crap!!! That’s me! Hahaha I noticed you were taking pictures but didn’t know if you were getting the truck. It doesn’t get a ton of attention out here. That’s so cool to see you on the forum.

Darn, I’m glad I asked. It’s interesting that the newer 4.0s didn’t come with it. Thanks for your insight!

Do y'all keep the manifold heat shield on or does it function fine with the shield off? I notice that the HO and later 4.0's don't have the heat shield above the manifold. The only reason I'm asking is it looks like a PITA to take off and put on to get to things below it (especially because I need to replace my manifold gasket), but I'm also worried about stuff like vapor lock if I keep the shield off once I go through the work of removing it the first time.

I’ve only ever seen two or three Comanches other than mine, and one of them was in Montana. One of my friends says he’s seen a black Comanche in downtown Bryan. He said he thought it was mine at first but it didn’t have the Texas decal on the Jeep lettering. He didn’t take a picture of the plate so I couldn’t look the truck up on the registry. I thought I’d throw a Hail Mary old-school style and ask if the owner of that black Comanche in Bryan is on this forum. I hope eventually I’ll run into him, but knowing my luck I won’t be in my Comanche at the same time for any impromptu pictures

I now know for the future that I’m going to take the top end off next time I need to remove my throttle body. I never want to touch that bottom end again, I think it was a fluke that I made it work. I think I just needed someone to believe in me. Being stuck in a parking lot at 10pm last night was pretty disheartening lol.

I GOT IT ON!!! I had a small pair of needle nose vise grips that I got the perfect angle/grab on and it popped right on. I put duct tape around the teeth touching the plastic to protect it, so I’m glad you mentioned doing something similar with the paper towel I’m very grateful that you told me it needs pressure to get these joints on. I would’ve been in for a rude awakening if I ordered the new part and was still unable to get it on by hand, not knowing I needed more pressure/leverage.

If what you’re saying is true, then maybe I can get this end back on with enough force. When taking the throttle body off, this side just kind of came off, so it could still indeed be too loose to reuse. I definitely can’t get the top end out without some sort of leverage. It’s being a real big PITA since I don’t have any good prying tools at the moment. No Jeep=no harbor freight

And yet I wouldn't trade it for anything else. Stockholm syndrome?

I feel like I've been posting way too much. One problem fixed creates two more problems. When removing my TB to replace the gasket, I took off this throttle link (pic isn't mine) from the bottom end (I couldn't get the top to come off and was worried about breaking it). When putting everything back together, that bottom ball end would no longer seat securely on the ball. There was already a ton of play in the link when it was connected so it was already very worn out. I ended up having to tape the link to the lever to get home. My question is: What is the right way to remove the link and install the new one? The bottom end is no problem, but I didn't have any luck with the top, unless there's a specific method that I'm not aware of. I am fine with breaking the plastic end but still don't know for sure how to install the new one. Will the metal ball just pop into the joint with enough pressure? I like knowing exactly what to do/expect when possible so the job goes smooth.

Alright guys, I made a thread previously about this issue, thought snugging up the manifold bolts fixed the problem, but it has returned in full force. I am going to go into much more detail because, at this point, I am at a total loss for what could be causing this high rev issue. I apologize for the length, I figured the more detail the better. The issue plays out like this: I start the truck, the revs shoot up immediately to 2000-2300 and stay there. Putting the truck in a gear drops the idle (like usual) to a cool 1500-1700RPM when completely still. The truck always wants to lurch forward when it is in this state, it is especially scary when in traffic because the revs are fighting the brakes and they're barely enough to keep the truck stopped. It feels like I have my feet on the gas and the brake at the same time. When I turn the truck off in this state, it shuts off hard and shakes the entire thing having to abruptly stop the motor, which can't be healthy for it. For this reason, one of my suspicions is that the throttle plate is getting partially stuck open. This makes sense logically as to explain my symptoms but I am more at a loss of what could be causing it. The most difficult part is it's intermittent. I find that, rather than it differing from startup to startup, the problem can persist for a full day or two and go back to normal for however long. Turning it off and back on does not fix the issue in most cases. I have had instances where the increased idle occurs for 10 seconds, 30 seconds, 1 minute, 5 minutes, and the entire length of every trip I've taken throughout a day (20-30 minutes driving total). The added inconsistency to the already intermittent nature is making it very frustrating. In the cases where the problem resolves itself, I see the revs crawl back down to a normal state and it drives perfectly fine afterwards. Even in cases where the revs don't get up to the 2000s, I've seen my idle in park hang out around 1200-1400 and my idle in a gear is right at 1000. This is much easier to deal with when trying to drive because I'm not fighting the truck to stop/slow down nearly as much, but I know it is the same issue occurring at a lower intensity. This also makes me think it could be some vacuum issue in the manifold gasket itself? If there's not a full seal, it makes sense that extra air would get sucked in and raise the idle, with the problem fixing itself in the rare cases that the leak gets a good enough seal to vacuum it off. All my other vacuum lines are good (tested with brake cleaner, no change in idle), but I haven't gotten around to checking the manifold gasket with brake cleaner/water since I'm writing this not long after it happened. It's on my to-do list when I have a morning off. Relating to this ^ are there any tips/how to for removing the manifold heat shield? I don't want to have to mess with the injectors/fuel rail to get it off, but I don't see another way nor do I see any guides online. I'm going to list related or adjacent fixes or checks that I have done pertaining to the idle so y'all know what has been done and not worked: New TPS (voltage tested), new IACV, cleaned throttle body (not taken off and fully deep cleaned; I have the gasket and is on my to-do list) and sea foam treatment, manifold bolts all snugged down (top of gasket vacuum tested w/ BC but not the bottom yet). It may not be related but all my sensor grounds are good, no resistance anywhere (cruiser tip 5). I remember since I've owned the truck from 2022, this problem was a once-a-month (if that) occurrence, but in the past few months, seemingly out of nowhere, the issue has become exponentially more common and severe (multiple days a week, multiple times a day). This few week period between my original post and this post is the longest I've gone without the throttle sticking once in a good few months. I have a satellite "issue" where, even if it idles normal on startup, it'll still rev up to the 2000s and come right back down. I am willing to bet that the cause for the high idle is also causing this issue. The amount it goes up is inconsistent and sounds different every time, so it seems more of an issue rather than a quirk. When neither of these issues occur, then at cold start, the RPMs will go up a normal amount and come down fast enough to kill the motor if I don't blip the throttle. This happens in all seasons, doesn't matter if it's cold outside, just the engine being cold. That's all I have right now. I am going to start recording every startup to capture some evidence and add onto this thread with those along with any attempts at repairs. I will be happy to share any more details if needed. TL;DR: Throttle stuck open on startup intermittently, I'm thinking either there is an intermittent vacuum leak in the manifold gasket or the throttle plate itself is getting stuck open.