Jeep tuning master thread

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Originally Posted by hyperbolecubed

You could also zero out the entirety of power enrichment and be more focused on the base fuel map.

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I was actually really wondering about this. The "PE" map doesn't make any sense to me, why not just add those values to the base map? I was thinking about zeroing it out and adding to the base map instead.

Regarding the trims, I don't have a wideband yet so my normal method is to reset the ECU trims then drive around for 30-40 min and go off the LTFTs. Won't disabling closed loop eliminate this as a tuning option?

EDIT:

I guess it makes sense in the context of emissions compliance. There's a PE and PT enrichment delay, so if you were to simply add the fuel in the base table you would get better drivability and more power but you'd have worse emissions. Still, I'm half inclined to zero out the PE and PT enrichment tables and add that fuel to the base table. Then you could more easily predict what will happen and smooth out the graph in a way that makes sense.

IDK, that just seems easier to me and would allow more consistency.

Disabling closed loop would enable open loop causing the ECU to use the base fuel map (O2 sensors will essentially be disabled and your scanner will say 0 in every cell when you data log). Whether there's still input from compensation tables I'm unsure. I zeroed out a few tables so I'll see what my wide band says.

When running closed loop, the ECU will use the O2 sensors to keep itself at stoich 14.7 to 1. Closed loop I'm sure is where the compensation tables shine as these adders richen the ratio based on rpm.

Thats what Im playing with is becoming dependent on the base fuel map for open loop.

When zeroing the compensation tables/adders be prepared for your initial readings (if you have a wideband) to run a little leaner. Otherwise everything seems to be fine so far. Will be working on timing advance next

I have a Magnum supercharger on a 2005 4.0L TJ Wrangler Manual. bigger injectors, 2 bar map sensor, altitude is 4400ft. The tuning detail supplied is very vague and I need assistance. the vehicle cranks and doesn't start. When it eventually does, it doesn't idle too bad but isnt happy either. I need help setting everything up to a point where the vehicle can be driven for log files to do some fine adjustments.

Attached in excel format is the file info that I transferred so HP tuners (tj stock file - Copy (1st tune).hpt
no Barometer or MAP info was supplied for the 2 bar map sensor that was supplied.

Please can someone assist me on this

Thank you

Attachment 151359
Attachment 151360
Attachment 151361

Great thread here, I'm working on a 2000 Cherokee 4.0l that I installed a 99 exahust manifold on with new o2 bungs to compensate for the Cali emissions, cats were clogged and I had a new manifold on hand. As I found out quickly it was going to need a tune, I have not hooked up a wideband yet but I got it running pretty decent using the left vs stft error graph. My question is what's the reason for the 2 base map tables (egr on\Egr off)? I made both table the same (egr off table) and took a few logs and it seemed to run ok. I then put the tables back to stock and got a few logs and didn't notice much of a difference aside from some more lean spots here and there that were not present before but it seemed to run the same. Just wondering if anyone has any input. I have been tuning ls stuff for a few years now but this jeep stuff is odd and a bit crude lol. Thanks in advance.

These jeeps dont have an EGR and unsure about when they do have them. However, most people just copy the one table like EGR on to the EGR off table so theyre the same.

Tuning the fuel table with the stock o2 sensors and going by LTFT and STFT will only bring you closer to stoich and wont give you more fuel. You have to be in Open loop to run off purely the fuel map. You'll need a wideband to properly tune

Here's my tune for my 2004 Jeep TJ Rubicon auto trans Pacesetter long tube header and I think Air Raid intake and bigger throttle body. Picked up a lot of power on the dyno. And the elevation aspect Chrysler puts in their tuning is atrocious. And it's not like there's a ton of jeeps at high elevation areas, like the moutiains.... LoL.
Oh and the trans tuning did absolutely nothing. It didn't matter what I changed in the trans tables, there was no difference in it. So I'm guessing there's something not working properly in the trans options. And I have raped some of the table so the trans and converter would do something different, but nothing. It also took me about a year before I could actually tune my jeep. I had one of the first MPVI2 modules. And HP tuners swore the problem was with my jeep and not the interface. I got the MPVI3 so I could do the c8 tuning and the newer vehicles etc... and suddenly, my jeep's pcm stopped giving the " aborted " write message with the MPVI3.Attachment 155326

Hi everyone, I'm a TJ owner from Australia and looking at getting the MPVI3 to try and resolve an issue with O2 sensors but thought I'd ask some questions here before spending the money on something that may not work.. The previous owner of my TJ damaged the PCM back in 2011 and got a rebuilt unit from a company called Solo PCMS in Florida. The TJ is a 2004 Australian delivered RHD 4.0L with 2 O2 sensors fitted - we didn't get the pre-cats so there is just one upstream and one downstream sensor. The problem is the rebuilt PCM appears to have been programmed for a US-spec model and keeps giving me errors for 4 different O2 sensors (P0135, P0141, P0155, P0161). I have a basic OBD scanner that clears the error codes but after a few cold starts they usually come back and I'm concerned that it may be causing excess fuel consumption.

I have taken it to a local tuning shop that has HP Tuners and they were able to switch off two of the O2 sensors but within a few weeks the errors started coming back. I don't have a way of checking what the PCM is doing and I'm not sure if the PCM is faulty or if it's just not communicating with the O2 sensors.

The main question is, are these error codes going to cause excess fuel consumption or any other performance issues? If there is no impact then I can probably just live with resetting the codes when they appear but if there is an impact on fuel economy I'd like to find a solution.

Thanks in advance!

IS the attached file the tune?

Hey All,
Been over a year, since I have posted on this particular thread. i’m shocked, and thrilled, that it’s still going !

To recap, I build a 4.6 stroker for my 2004 Wrangler TJ 4.0. Had a lot of issues getting it up and running, what a nightmare. That’s what happens when have old-school experience and mentality, and Assume you can just figure out the technology.

Long story short, The mule runs great.

JayOh— I would highly recommend purchasing the correct pcm for your particular vehicle. Especially, if you’re planning on getting the HP tuner. I have discovered it always better to work with a known good foundation. This removes any questions about your base, and the inconceivable amount of troubleshooting variables, it can encompass.. It is vital to start with a known good, and go from there.

Any luck, I should have my HP tuner for Christmas! Wish me luck!

I found a tuner locally who will re-tune my vehicle for me and leave it unlocked, So I can reverse engineer and learn.

Let’s keep thread this going!!

I will post what I learn as I go! My disclaimer… This is not something I’m going to be posting on daily or weekly. Monthly, maybe.

The Geek

I remember back a couple years when I was originally looking at tuning my jeep. HP tuners used to have a manual they sold, a tuning guide (course) I believe, covering the 97-04 jeep wrangler. For the mpvi 2+ I think.

Anyone else ever see that?

I’ve been looking all over to see if I can find an old copy, but no luck.

We developed a good boosted tune for those as we now offer turbo kits for 4.0 engine. If someone need a base file pls hit me up. Easy 250hp on low boost on 93

https://fb.watch/w_oXrnP6Vi/

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Originally Posted by veeefour

We developed a good boosted tune for those as we now offer turbo kits for 4.0 engine. If someone need a base file pls hit me up. Easy 250hp on low boost on 93

https://fb.watch/w_oXrnP6Vi/

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How much do you guys charge for tuning 4.0 with HPTuner and how much your turbo kits? I?m currently supercharged my 2006 4.0 and would like to dial it a bit to get best power/fuel etc as it?s on just genetic tune.

That said, is 91/93 octane a must or is there room to tune it down to 87? I only got one gas station with 93 and 91, like one pump and usually for some reason it?s out. 1 hour drive to fill up at another isn?t smart lol so if there?s a way to get performance out of 87 without hurt to the 4.0 I?d be interested.

Thanks in advance.

Email me directly or whatsapp

Hello Everyone, i have a 2002 jeep TJ with 4.0L, i have the BBK 62 MM throttle body and i notice that in the Viewer that the throttle position starts at 14.1% and maxes out at 76.1 %, the mechanical pedal action does go to zero and is wide open when pedal is depressed to floor. i dont see a way to calibrate the TPS in the JTEC+. Anyone else have this condition with BBK throttle body.

What are all y'all using for a wide band? Is the AEM X-Series OBDII Wideband AFR Controller Gauge that is on the HPT website a workable option for these vehicles?

I'm thinking one from PLX would work well as the processor will give a wideband signal for the prolink cable and narrow for the ECM.

Using MPVI3 to read/write 2001 Jeep Cherokee 4.0. After countless tries i have achieved to read the ECM. But I am having an issue writing a tune to my Jeep ECM, it gets past the radio warning, ign off, ign on, then when it gets to the point of erasing it says that it aborted, and write failed or something like that. Anyone having same issue on March 2025 ? Former threads who use MPVI2+ suggest using Beta version of VCM Suite to write? Do you agree or have any other suggestions for MPVI3 ?

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Originally Posted by SerdarD

Using MPVI3 to read/write 2001 Jeep Cherokee 4.0. After countless tries i have achieved to read the ECM. But I am having an issue writing a tune to my Jeep ECM, it gets past the radio warning, ign off, ign on, then when it gets to the point of erasing it says that it aborted, and write failed or something like that. Anyone having same issue on March 2025 ? Former threads who use MPVI2+ suggest using Beta version of VCM Suite to write? Do you agree or have any other suggestions for MPVI3 ?

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I use the beta for everything and had no issues.

Hey guys, I?m new to tuning and have never done anything like this. I?m looking for some starter tips and things to look out for so I don?t blow it up because it is my daily driver. I bought the MVPI3 and based on the last response I need to download the beta version to be able to get into the computer module. Anything helps and I?m willing to listen to what anyone has to say. Thanks.