PCM questions.

[Powerman04]

Alright. After looking at mods and sort of learning my way through engine workings, I narrowed my trans shifting woes to the PCM. Now, I have no issues spending the money in the right places, but when messing with the PCM I have to be careful. In my reading, I found the method of getting a replacement PCM and sending it into B&G for their flash. Are these the only people who do this kind of thing, or is there anyone else someone has had good experiences with? Also, living in VA, emission inspections are inevitable, so does anyone have bad experiences with doing this and then all of a sudden you can't pass emissions? Finally, in looking at all this info, I'm still finding things I don't quite understand yet, like torque management, torque converters, stall points, ect. Any info on these things would be great, simply for my understanding. Sorry for the long post and questions all over. I'll summarize it here.

1. Buying a replacement PCM and getting the B&G flash seems to be the best bet in my reading. What PCM am I looking for specifically? (PN would be nice.)
2. Is B&G the only company to do this kind of work, or are there other (maybe local and also reputable) places?
3. After such a mod, is there known issues with emissions tests?
4. Some explanations on what torque management, torque converters, stall points, ect. in reference to our KJ's would be great.

 

[flair1111]

bump

 

[KYLiberty]

Alright. After looking at mods and sort of learning my way through engine workings, I narrowed my trans shifting woes to the PCM. Now, I have no issues spending the money in the right places, but when messing with the PCM I have to be careful. In my reading, I found the method of getting a replacement PCM and sending it into B&G for their flash. Are these the only people who do this kind of thing, or is there anyone else someone has had good experiences with? Also, living in VA, emission inspections are inevitable, so does anyone have bad experiences with doing this and then all of a sudden you can't pass emissions? Finally, in looking at all this info, I'm still finding things I don't quite understand yet, like torque management, torque converters, stall points, ect. Any info on these things would be great, simply for my understanding. Sorry for the long post and questions all over. I'll summarize it here.

1. Buying a replacement PCM and getting the B&G flash seems to be the best bet in my reading. What PCM am I looking for specifically? (PN would be nice.)
2. Is B&G the only company to do this kind of work, or are there other (maybe local and also reputable) places?
3. After such a mod, is there known issues with emissions tests?
4. Some explanations on what torque management, torque converters, stall points, ect. in reference to our KJ's would be great.

1. Different part numbers for different years. Try to find one from a similar KJ of the same year as yours.

2. B&G is the way to go. Chrysler is very secretive in their programming. B&G really knows what they are doing.

3. May not pass emissions. That is one of the reasons you keep the original so you can swap it back in for tests.

4. Talk to Wayne at APS Precision. He is very good on torque converters and they can build what you need.

 

[Powerman04]

What advantage would paying so much to have the PCM work done have over simply having it on a dyno and tweaking it from there? This would be after I finished adding the exhaust and such, of course. (If I'm just way off here then do let me know, first time I've done things like this to any vehicle eek2.gif)

 

[tjkj2002]

What advantage would paying so much to have the PCM work done have over simply having it on a dyno and tweaking it from there? This would be after I finished adding the exhaust and such, of course. (If I'm just way off here then do let me know, first time I've done things like this to any vehicle eek2.gif)

$$$$$ is the difference.Your looking at a couple of thousands of dollars to have the PCM tuned on via dyno.

You will have to have the VIN programmed in the PCM before it will work in your KJ,dealership time there.

 

[Powerman04]

My biggest points on doing this is the shift points and apparently the torque management or converter (dunno the difference yet.) I rode in my friend's CRD and was completely jealous of the torque. I know I'll never reach that amount, but the amount I do get when passing someone on the highway or going up a hill is embarrassing and downright annoying. As far as I know the PCM is the problem here, since if you try to correct it otherwise, the computer compensates, or so I've read.

 

[bmrrwolfe]

My biggest points on doing this is the shift points and apparently the torque management or converter (dunno the difference yet.) I rode in my friend's CRD and was completely jealous of the torque. I know I'll never reach that amount, but the amount I do get when passing someone on the highway or going up a hill is embarrassing and downright annoying. As far as I know the PCM is the problem here, since if you try to correct it otherwise, the computer compensates, or so I've read.

Kinda a question for you on this, when passing on the highway its embarrassing for you, how so, are you lifted bigger tires etc? Unless I have the A/C I have no problem accelerating even from 60-80/90/100?
The only "performance" if you can even call it that is a cherry bomb glasspack put in about 2 FT from where the cats meet.. no pipe after it and I know its killing me not having any back pressure. (oh and it was done by the PO and still debating on what I really want to do..)
But back to the subject, the KJ isn't meant to be fast since it is a Jeep and all but mine and my sisters have plenty of power, even with the added weight I run on mine.
Although it doesn't hurt to add HP, its going to cost and cost a lot to do it right with minimal gains.

I checked out B&Gs site and its $350 for a reflash which actually less then I thought and it includes shipping etc.
Anyone have any numbers on the improvement from running a flashed PCM, LTT or similar intake, catback system and maybe a fastman TB?

http://www.bgperformancepcm.com/#jeep

 

[Powerman04]

Kinda a question for you on this, when passing on the highway its embarrassing for you, how so, are you lifted bigger tires etc? Unless I have the A/C I have no problem accelerating even from 60-80/90/100?
The only "performance" if you can even call it that is a cherry bomb glasspack put in about 2 FT from where the cats meet.. no pipe after it and I know its killing me not having any back pressure. (oh and it was done by the PO and still debating on what I really want to do..)
But back to the subject, the KJ isn't meant to be fast since it is a Jeep and all but mine and my sisters have plenty of power, even with the added weight I run on mine.
Although it doesn't hurt to add HP, its going to cost and cost a lot to do it right with minimal gains.

I checked out B&Gs site and its $350 for a reflash which actually less then I thought and it includes shipping etc.
Anyone have any numbers on the improvement from running a flashed PCM, LTT or similar intake, catback system and maybe a fastman TB?

http://www.bgperformancepcm.com/#jeep

I do realize that the KJ is a brick on wheels and I'm not going to get a race car from it. Embarrassing might of been the wrong word to use. It's more frustrating then anything, and I honestly think it's a bigger strain on the parts if it's constantly swapping gears. Could be wrong but my opinion. My specs are in my sig, but yes I'm lifted. The tires aren't huge compared to stock but I do realize it may make a difference. Accelerating at that high a speed is no issue. There is little chance of needing to downshift by that point since you're already at a higher rpm. My issues lie normally around the 40-55 mark. Here the trans likes to hunt for gears, shift into OD, and nearly choke your motor to death when managing torque. Higher rpm shift points may help as well but that's getting into hope and dreams.
I've looked at the B&G as an option, and am slowly realizing it's possibly the only option besides being cheaper and chipping it (which may or may not work) and leaving OD off while in town (which I do) but that still doesn't solve the torque issue. I'm more in this for the information out there then simply saying the KJ feels like a brick on wheels but I want it to feel like a race car. I'm just certain that these issues have fixes and I'm curious how these fixes actually fix the issue, lol.

 

[bmrrwolfe]

I do realize that the KJ is a brick on wheels and I'm not going to get a race car from it. Embarrassing might of been the wrong word to use. It's more frustrating then anything, and I honestly think it's a bigger strain on the parts if it's constantly swapping gears. Could be wrong but my opinion. My specs are in my sig, but yes I'm lifted. The tires aren't huge compared to stock but I do realize it may make a difference. Accelerating at that high a speed is no issue. There is little chance of needing to downshift by that point since you're already at a higher rpm. My issues lie normally around the 40-55 mark. Here the trans likes to hunt for gears, shift into OD, and nearly choke your motor to death when managing torque. Higher rpm shift points may help as well but that's getting into hope and dreams.
I've looked at the B&G as an option, and am slowly realizing it's possibly the only option besides being cheaper and chipping it (which may or may not work) and leaving OD off while in town (which I do) but that still doesn't solve the torque issue. I'm more in this for the information out there then simply saying the KJ feels like a brick on wheels but I want it to feel like a race car. I'm just certain that these issues have fixes and I'm curious how these fixes actually fix the issue, lol.

To be honest I thought that a flash was more of a $1000 job, but even with a Ebay PCM (to save the stocky) for $150-200 and the $350 to B&G thats still only $500-550, not cheap but after adding a true intake can be done for $100 fastman TB another $100-150 I think, and get a custom exhaust made up, a true dual with Flowmasters or Magnaflows for around $300-400, so i total of $1000-$1100 which isn't that bad for true power, as long as it all actually works together.

 

[Powerman04]

I've been talking to someone on LOST about how he took his KJ to the dealer and they ended up flashing his PCM and installing a new (improved so he says) torque converter.

On his paperwork he told me what they all did.
1 torque converter Part# 5093944-AE
1 seal Part# 4412475
ATF+4 transmission fluid
pulled trans and replaced torque converter
flashed and updated PCM

Anyone else have any insight? It seems the right direction for my issues since he described that the shifting and power was much better afterwards. I'm also trying to figure out what this flash actually did.

 

[Powerman04]

Bump.

 

[rockymountain]

To be honest I thought that a flash was more of a $1000 job, but even with a Ebay PCM (to save the stocky) for $150-200 and the $350 to B&G thats still only $500-550, not cheap but after adding a true intake can be done for $100 fastman TB another $100-150 I think, and get a custom exhaust made up, a true dual with Flowmasters or Magnaflows for around $300-400, so i total of $1000-$1100 which isn't that bad for true power, as long as it all actually works together.

To do it right I think you would have to do your mods bmrrwolfe and the flash. You can add aftermarket crap on it all you want, but mostly the stock pcm is going to compensate and set you right back where you started. Then the gains wouldn't be worth it in my opinion. The 3.7 is a hefty engine and is not made to blow your socks off. Its made to last and be reliable. That is what I hear time and time again.

 

[Powerman04]

Interesting.

http://www.wkjeeps.com/misc/LX/TSB/TSB_2100207b.pdf

 

[Warren.fischbeck]

Looks like it's limited to '07, is that your jeeps year?

 

[Powerman04]

I thought that too but then read the note under the years. and it's 04

 

[Warren.fischbeck]

Print it out and see if you can get it flashed at the dealer... I don't think it could hurt any.

 

[Powerman04]

Already printed and saved the site. Someone from LOST referenced this and had the work done, both flash and torque converter. Said after it was beyond night/day. He had it under warranty though, and I'm currently broke, so, can't try yet.

 

[Warren.fischbeck]

Sounds like a trip to the stealership to ask some harmless questions are in order... They may just flash it to be nice, especially if they think they can get a torque converter out of you down the road.

 

[Powerman04]

Sounds like a trip to the stealership to ask some harmless questions are in order... They may just flash it to be nice, especially if they think they can get a torque converter out of you down the road.

If I found a dealer like that, I'd never buy from anyone else. Knowing them they would insist they must be done together anyway.

 

[Warren.fischbeck]

You can see what can be bought on trade... I was amazed on what a stealership would do for free or no labor when they found out that I work on computers for a living.