Beating a dead horse (4.0 42RLE)

[schmidtke_c]

Well little update, pulled some of my old records for the jeep September of 22 it got new plugs, wires, a TPS, IAC but I noticed it still had a little miss so I got new plugs and wires today no real difference in top end performance but it did wake it up a little however they old plugs (autolite xp) looked fine. So to refresh its got new upper cats and lower cat and pipe all the way back to the tail, plus the parts listed above.

I understand its like running with plywood but I still think I'm underperformed here. There has to be a reason why I'm hitting 60mph and thats like a wall. Don't matter if its in o.d or not it will not go past this point. I did discharge the system (positive cable to ground) and it started shifting a lot harder on the way to work.. but no check engine lights nothing that really tells me anything valuable.

While doing wires i did notice a small hole on the exhaust next to the midhanger probably from when I had it installed and welded and there is a little bit of blow by on the upper exhaust by the cats I need to get under there and tighten that stuff up I just ran out of time before work.

 

[B00mb00m]

It worked- there is a thread somewhere but results are a little bit varied

It’s not a dynamic difference but enough I have enjoyed it-

Anything that helps you live with the ol’ 42 transmission is a good thing.

Remind us do you have the stand alone TCM like 04 or the single PCM 05-06?

 

[schmidtke_c]

Remind us do you have the stand alone TCM like 04 or the single PCM 05-06?

It's an 05 single unit and fwiw has 101k on it.

 

[txbemis69]

my 06 4.0, auto had 3.73 gears and was a dog with 4th/overdrive being useless. i regeared it to 5.13 and it was a vast improvement from before. it could still be geared lower but, with a 30/35 combo for axles 5.13 is the best one can get. super 30/35 upgrade with elockers & gears was not cheap but, well worth it coin spent.

 

[schmidtke_c]

my 06 4.0, auto had 3.73 gears and was a dog with 4th/overdrive being useless. i regeared it to 5.13 and it was a vast improvement from before. it could still be geared lower but, with a 30/35 combo for axles 5.13 is the best one can get. super 30/35 upgrade with elockers & gears was not cheap but, well worth it coin spent.

That's how I felt when I originally purchased the jeep because it came on 33's but with stock gearing and was just the biggest turd I've ever seen. When I had the 30/35 under it I geared to 4.56 and liked how that felt but when I put the 44 on I geared up to 4.88 with a no slip in the front and a trutrac in the rear but there's just so much to be had. It feels like the day I bought it and I'm super bummed especially because our place up north is a 2.5 hour highway drive and I can't do highway speeds.

 

[Artsifrtsi]

2.5 hour highway drive and I can't do highway speeds.

Maybe my '05 is some sort of special TJ? Yes, I need to regear, and is is more of a dog than it was on the stock tires... But I have a 4.0/NSG/3.07 running 33's... No problem with highway speeds, in fact I have to check speeds all the time... most of the time in 6th. I don't notice it off-road much, because I'm generally in 4lo...

Is the 42 that much of a power suck?

This is like trying to convince a friend that his 2016 JKR 2dr with NSG was slow because he was used to his ss Camaro... he drove my TJ (as it sits now) and was surprised at how much more power it has over his JK (seems a common issue on the 2dr/6 sp, they detuned the crap out of the throttle).

 

[schmidtke_c]

Attached is some photos from after my 10/15 mile ride home tonight, from the looks of it my o2's are reading and things look "normal" within reason... I just dont understand I'm really starting to get to the point where I want to cut my losses. Its so frustrating not knowing what the actual problem is.

I'm not sure what my next move is.

 

[AndyG]

Remind us do you have the stand alone TCM like 04 or the single PCM 05-06?

Both, my 05 has the Wranglerfix pcm

White is ‘04

 

[schmidtke_c]

5-12 update

I spent the weekend going through all the wires under the hood didn't see anything that was split or worn through. Pulled every plug on all the sensors and reconnected them, pulled both o2 sensors before the cats and pushed an endoscope in there they looked clear and the o2's looked good, not super carbon'ed up or anything like that. Still having issues.

Didn't check the fuel pressure but I did order a new fuel pump and a fuel filter so I am going to check them out Friday. Also got to thinking at work.. last summer (maybe even early fall when it was still warm) I had the radiator blow up when I got to work, I ended up replacing the unit while I was here and I don't recall if I ever topped off the trans fluid afterwards. I say this because I park the jeep in the winter. anyways, I'm almost curious if maybe that is contributing in some way to all this now that its getting warm outside...

 

[schmidtke_c]

5-15. update

Used a scanner to run through the transmission codes, nothing there, still not throwing any codes for anything system wide other than the battery disconnected stored code. was able to clear that with this scanner. Ordered a Bosch fuel pump and a fuel filter and a back pressure tester. going to throw the fuel pump on that tomorrow morning as well as do that pressure test and see where we stand. will keep updated. also for the record bank 1 sensor 1 looks like the previous owner clipped a wire and reran it to the pcm, don't believe this is the cause of the issues though.

new in 22'
- IAC (walker)
- TPS (walker)
- all o2's (NTK)
- Catback from manifold to rear (flowmaster)

new in 25'
- Coil (ngk)
- Plugs (champion)
- Wires
- Air temp sensor (ntk)
- Fuel pump (Bosch)
- Fuel filter (FVP)

 

[Strizzo]

I also felt like mine feels particularly sluggish with the auto, much more so than the manual i've driven before, but it does seem to start to move if you really put your foot in it and get the revs up above 3,000. The auto just seems to always want to shift as soon as possible so it doesn't get into the power band unless you're really on it.

 

[jjvw]

I also felt like mine feels particularly sluggish with the auto, much more so than the manual i've driven before, but it does seem to start to move if you really put your foot in it and get the revs up above 3,000. The auto just seems to always want to shift as soon as possible so it doesn't get into the power band unless you're really on it.

Regearing helps that behavior a good amount. 32" tires should have 5.13. Turning OD off around town raises the shift points as well.

 

[Strizzo]

Regearing helps that behavior a good amount. 32" tires should have 5.13. Turning OD off around town raises the shift points as well.

Im running 5.13s and 33s. the trans sees the lower load and shifts instead of holding gears unless I keep my foot in it. Probably why the shift point adjustments made available by HPTuners seems to wake them up so much.

 

[jjvw]

Im running 5.13s and 33s. the trans sees the lower load and shifts instead of holding gears unless I keep my foot in it. Probably why the shift point adjustments made available by HPTuners seems to wake them up so much.

538 would be even nicer.

2003-4 has a standalone transmission controller that cannot be reprogrammed other than one unreviewed example.

 

[Mike_H]

5-15. update

Used a scanner to run through the transmission codes, nothing there, still not throwing any codes for anything system wide other than the battery disconnected stored code. was able to clear that with this scanner. Ordered a Bosch fuel pump and a fuel filter and a back pressure tester. going to throw the fuel pump on that tomorrow morning as well as do that pressure test and see where we stand. will keep updated. also for the record bank 1 sensor 1 looks like the previous owner clipped a wire and reran it to the pcm, don't believe this is the cause of the issues though.

new in 22'
- IAC (walker)
- TPS (walker)
- all o2's (NTK)
- Catback from manifold to rear (flowmaster)

new in 25'
- Coil (ngk)
- Plugs (champion)
- Wires
- Air temp sensor (ntk)
- Fuel pump (Bosch)
- Fuel filter (FVP)

I have 35’s and 4.88’s with the 42rle. No problems cruising on the highway. I’ll slow down on big hills, and I know 5.38’s would be “better,” but I haven’t needed to make that change yet.

I’d do a compression test on your engine. I’m tickling 160,000 miles, and 80 mph is still pretty easy to get to.

 

[Harold&Cat]

We ran 32 inch tires on ours for years with the factory 3.73 gears and the 42rle. I had no problem running highway speeds untill the Cats stopped up . Ran fine again after new Cats . Don't believe I ever tried to go over 85 mph , but running 75 to 80 was not a problem . Yes it was under-geared and when traveling under 60 I turned off the overdrive .

 

[schmidtke_c]

I have 35’s and 4.88’s with the 42rle. No problems cruising on the highway. I’ll slow down on big hills, and I know 5.38’s would be “better,” but I haven’t needed to make that change yet.

I’d do a compression test on your engine. I’m tickling 160,000 miles, and 80 mph is still pretty easy to get to.

That's kind of where I was heading honestly. I mean it hasn't been until recently that it was this bad. I knew it would be a little rough but doable, coming from 4.56's and 33s. It wasn't perfect but it was OK. Now its down right disrespectful how bad its gotten.

We ran 32 inch tires on ours for years with the factory 3.73 gears and the 42rle. I had no problem running highway speeds untill the Cats stopped up . Ran fine again after new Cats . Don't believe I ever tried to go over 85 mph , but running 75 to 80 was not a problem . Yes it was under-geared and when traveling under 60 I turned off the overdrive .

If the cat was backed up wouldn't it be glowing red hot or something obvious that would at least case a code? Even if it was a o2 code I mean something at all?

 

[schmidtke_c]

Can anyone Interpret what im seeing here? I think it all looks normal and in line. Nothing is standing out that great?

 

[Harold&Cat]

Didn't have any codes and don't remember seeing glowing Cats .

 

[schmidtke_c]

Update 5-19:

Did the fuel pump, no sauce didn't bother to do the back pressure test just went and bought new cats. Gonna install them sometime this week. I figure at this point there's not a whole lot more to replace... damn jeeps. Will update when I get to that point any insight is appropriated anyways.