Does anyone run a tune on their TJ?

That is too bad Chris. I wonder if you could get your fuel mileage to improve if you could get this to work.

This is my ONE fear with doing email tunes. I had issues with the tuner on my Harley when Id bought 2 extra credits to tune my ex's wife & a friends bike. Locked my tuner up for some reason and had to send it into Dynojet. But they did fix it quickly.

The tuner I had in my Ram I never had any issues with. The SCT tuner I have is a used unit and I'm hoping it'll work on this new engine. The PO said he'd unlocked it so we'll see.
 
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The MPVI2
Interesting, the baud rate error was a known issue with the earlier version of the interface.

Same error hard wired vs Bluetooth?

In regards to tuning the 4.0L I’ll concede that you are not going to turn it into an Ecoboost. That said though on my 2005 4.0/auto I have been able to dramatically change the on road driving experience with a few degrees of timing where it counts and a ton of trans adjustments. Still running 87 octane (TX low grade) and never a ping or rattle. Zero “performance” mods beyond the software adjustments. 120k miles and running strong with an average 15mpg on 33’s with 4.56’s.
 
Interesting, the baud rate error was a known issue with the earlier version of the interface.

Same error hard wired vs Bluetooth?

In regards to tuning the 4.0L I’ll concede that you are not going to turn it into an Ecoboost. That said though on my 2005 4.0/auto I have been able to dramatically change the on road driving experience with a few degrees of timing where it counts and a ton of trans adjustments. Still running 87 octane (TX low grade) and never a ping or rattle. Zero “performance” mods beyond the software adjustments. 120k miles and running strong with an average 15mpg on 33’s with 4.56’s.

When I had a tune before it made a substantial difference. However, now that I have a new ECM and I’m back to no tune I definitely notice how it negatively affects driving.

I’m not sure how knew my HP tuners dongle is but I’m going to attach a picture of it, maybe you can tell me.

In regards to Bluetooth versus no Bluetooth, I’ve only tried it hardwired without Bluetooth and it doesn’t work. Still gives me the same error.


257C402E-10C2-4515-B601-83DA7E28AA2E.jpeg
 
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When I had a tune before it made a substantial difference. However, now that I have a new ECM and I’m back to no tune I definitely notice how it negatively affects driving.

I’m not sure how knew my HP tuners dongle is but I’m going to attach a picture of it, maybe you can tell me.

In regards to Bluetooth versus no Bluetooth, I’ve only tried it hardwired without Bluetooth and it doesn’t work. Still gives me the same error.


View attachment 251450View attachment 251451
Try a different USB cable. You shouldn’t have an issue with that dongle.

If that doesn’t get it I wouldn’t hesitate to email support@hpt… William is super responsive with device issues.

edit - delete that pic with your serial number
 
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Try a different USB cable. You shouldn’t have an issue with that dongle.

If that doesn’t get it I wouldn’t hesitate to email support@hpt… William is super responsive with device issues.

edit - delete that pic with your serial number

Okay, I'll try that.

I'll also email him and see what he says.
 
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After my head gasket leaked I had the head ported and polished with bigger valves. I was told that I wouldn't see much gains with just the P&P so I also did a mini stroker. Saw a pretty large gain in fuel mileage but that has gone down after the first tune as I guess I was way to lean even with upgraded injectors and I unfortunately asked to be tuned on 87 octane. Waiting on Ryan's second file with a higher octane tune. The tune does help the stroker at idle and it's nice to disable the 2nd 02 sensor :) I just wish I could see some numbers of before and after because it honestly doesn't feel that much different. Might need to dyno it or race another jeep with the same setup as mine just to feel better about the time that has gone into the rebuild.
 
I am expecting to Fuck off the stupid pre cats and o2 sensors on my 06 eventually! having a 6 cylinder gas guzzling "Brick" with emission controls that are just "The Emperors New Cloths" Plus we dont Smog or MOT in Australia ( for our UK brethren) :) But I do want to ask about exhaust smell for those that have deleted their cats.

Thank you for clarifying the obvious. Don't know why people who don't understand the subject have to comment more than people who do. Reading forums is more wading through bullshit than anything else
 
Changing the timing tables makes a pretty good difference. I never turn off my OD unless I am using it for engine braking. I found that timing is reduced when load on the engine is increased. As vacuum goes down in the intake, the timing is reduced way more than needed. I have seen timing pulled all the way to 17 btdc. Timing at wide open throttle should be around double that. When you start up a hill at highway speeds the ECU reduces power by retarding the ignition timing. Tuning the timing tables definitely helps. I don't think stockish tires and small lift has a problem because it requires less power vs bigger tires and lift.
 
Changing the timing tables makes a pretty good difference. I never turn off my OD unless I am using it for engine braking. I found that timing is reduced when load on the engine is increased. As vacuum goes down in the intake, the timing is reduced way more than needed. I have seen timing pulled all the way to 17 btdc. Timing at wide open throttle should be around double that. When you start up a hill at highway speeds the ECU reduces power by retarding the ignition timing. Tuning the timing tables definitely helps. I don't think stockish tires and small lift has a problem because it requires less power vs bigger tires and lift.

I have seen you mention in this more than one thread. I wonder why the factory tune is the way it is. Perhaps for reduced emissions? The engineers doing this at the factory would have considered multiple options before finalizing all this so I am curious as to what the real reason is.
 
I'm pretty sure emissions played a part, but I don't really think it is much of an issue in stock form. Another thing is that with the lack of knock sensors the engineers were probably super conservative with the tune.
 
I have seen you mention in this more than one thread. I wonder why the factory tune is the way it is. Perhaps for reduced emissions? The engineers doing this at the factory would have considered multiple options before finalizing all this so I am curious as to what the real reason is.

I have a hypothesis on this timing observation: the in line 6 (pushrod design)generates a lot of heat under the intake, throw in a catalytic converter and you got a lot more heat. Now throw some of that 85 octane that’s out there into the mix and a driver that is not familiar with term “lugging a motor“- the safe thing to do is pull that timing back in that quadrant to avoid detonation. I think it is a compromise on reliability/warranty costs. Anyways like I said- just a hypothesis.
I would totally be game on to advance those table.
 
Does make me wonder if I need to retard the timing as much as I do or at all even with my supercharger. I've got some bigger injectors and a 2bar map sensor to go in this summer, maybe I should get a knock detector too and see what I can get out of it.
 
20 odd plus years ago when information, like above was only available in magazines, the same questions were asked and answered the same way. It's like driving a brick through the wind, it is what it is. I remember someone saying that Chrysler got all the HP out of the 4.0 engine that it could, and went over the the v6. for a power boost.
 
20 odd plus years ago when information, like above was only available in magazines, the same questions were asked and answered the same way. It's like driving a brick through the wind, it is what it is. I remember someone saying that Chrysler got all the HP out of the 4.0 engine that it could, and went over the the v6. for a power boost.

The big difference is that 20 years ago, we were not able to tune the TJ PCM. It has only been about the last 5 years that we have and that doing so has become accessible.
 
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I have seen you mention in this more than one thread. I wonder why the factory tune is the way it is. Perhaps for reduced emissions? The engineers doing this at the factory would have considered multiple options before finalizing all this so I am curious as to what the real reason is.

Reduced NOx emissions, also lack of a knock feedback system. The factory has to tune the engine for all scenarios. Low octane fuel, hot climates, high elevations are all considerations. The cast iron cylinder head is also a big limiting factor. Modern aluminum heads dissipate more heat in the combustion chamber allowing for more aggressive timing and higher compression. Chrysler could have modernized the 4.0 with a crossflow aluminum head and maybe overhead cams, but the choice to go with a different already designed v6 was probably more appealing.
 
I firmly believe that a stock 4.0 with an intake kit, header, free flowing exhaust and a good tune on 91+ could realistically add 15-20%. Most of the power would be gained above 3500 rpm and not particularly useful to most folks.
 
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20 odd plus years ago when information, like above was only available in magazines, the same questions were asked and answered the same way. It's like driving a brick through the wind, it is what it is. I remember someone saying that Chrysler got all the HP out of the 4.0 engine that it could, and went over the the v6. for a power boost.
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Contrary to one persons assertion, our resident tuning guru says otherwise...

(posted in January '21)
"We specialize in Dodge/Jeep/Chrysler engine and transmission calibration, from 96 model year to present day. We have been doing so since 2011.
As it pertains to this forum, I cover the 97 (96.5 if you really want to split hairs) thru 06 TJ. YES this includes the 2.4 and 2.5.

We have been tuning these engines for the last 10 years. We have held the pump gas 4.0-based HP and 1/4 mile record, while still running a factory controller. We have held such records for 5 years running."



IMO, this is the best thread to find out what can be done with the tuning for these TJs.

https://wranglertjforum.com/threads/frp-tuning-for-97-06-tjs.45983/post-784058
 
I firmly believe that a stock 4.0 with an intake kit, header, free flowing exhaust and a good tune on 91+ could realistically add 15-20%. Most of the power would be gained above 3500 rpm and not particularly useful to most folks.

The static compression ratio is 8.7 and dynamic compression ratio is 7.47. Would a 4.0 tuned and modified like posted above benefit much from octane higher than 87?