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Unitronic Stage 2+ (KO4) - How Unitronic Fixed My Ongoing Issues

allset

Go Kart Champion
Unitronic Stage 2+ (KO4) - How Unitronic Fixed My Ongoing Issues

++ The below narrative is based on my personal, firsthand experience with my current 2010 MK6 GTI. All statements on misfires and power loss were either logged personally and/or were done by a professional shop in my presence (with the methanol system disabled) ++

As many of you may or may not know, I have had ongoing issues with my mk6 since going stage 2 about two years ago. I have been fairly vocal about the problems by starting a few general threads and working with my prior tuner to get them addressed via logging and part swaps, so much of this is old news.

Originally, the main problem at my prior tuner’s Stage 2 was a loss of power and fault code P0088 (fuel rail pressure too high) being thrown weekly. I would clear the code and the power would instantly return only to slowly fall off over the next 2-4 days becoming boggy and slow. I would clear the code again and it would instantly be crisp and pull hard. The only thing I could attribute this instant power return to was the resetting of fuel trims to 1 upon code clearing even though my STFT & LTFT were never more the 5% in either direction from 1. That is the only part of this that is conjecture on my part. The difference in power was extreme upon doing this and I could find no other mk6 locally that would do this after resetting the fuel trims.

During this 2 year cycle of power loss and code clearing, my prior tuner did try to address this issue via logging with me back & forth. To try and identify possible hardware issues as the cause, I replaced the ECU once, the HPFP once, the in-tank fuel pump once, the G247 fuel pressure sensor twice, MAF sensor twice, fuel filter twice (6 bar & 6.4bar), all 4 coil packs 3 times, all 4 spark plugs 3 times, all 4 fuel injectors once, and the intake manifold once. The power loss continued unabated. I also had the car checked and logged by 3 different shops and my VW dealer during this time and none could find why it was acting this way.

I finally went KO4 with my prior tuner in July 2012 and started getting misfires in neutral. The P0088 code stopped throwing weekly but did continue to do so occasionally. I still had the power loss and still needed to reset the fuel trims by clearing codes (even if there is no code, hitting “clear code (DTC)” button will reset the trims to 1). So, as I would raise the RPM’s to 3500-4000, I would get 35-45 misfires in less than 60 seconds mainly in cylinders 2 & 4. I could feel and hear the misfires as I watched the counter record them; it was loud, fast and unmistakable. I also was getting random misfires under load, timing pull, over-boosting request and boost oscillation. In short, the car ran horrible most of the time. Again, I sent logs to my prior tuner to figure out what was wrong. I was mostly concerned with the misfires and power loss.

During this time, end of January 2013, I had a full teardown carbon cleaning done by KMD b/c I was at 58,000 miles and I was convinced the misfires had to be carbon/valve related. It kept misfiring even after the cleaning. (SEE LINK BELOW FOR BEFORE AND AFTER PICS OF THE CARBON CLEANING) I did find a hairline crack in my DP at the turbo flange so I sealed the crack with clay and high temp silicone just before I had the DP replaced to see if the misfires could be related to that as unlikely as it was. The crack was sealed very well but the neutral misfires continued. I also scoped the cat which was intact and fine.

Being at the end of my rope and done throwing parts at the problems, I approached several other tuning companies and presented my issue history. Unitronic (John) was the only one who took the time to seriously listen to me, review my logs and give me feedback on the numbers, not immediately blame hardware. I was very happy to hear the suggested solutions did not include more hardware changes.

UNI's suggestion to fix my issues was as follows:

1. Flash back to VW OEM software to rule out any underlying hardware issues/codes that any aftermarket tuners software may inherently suppress as a normal function of its operation.


I flashed back to VW OEM software and logged misfires in neutral and under load. I did not get any misfires in neutral or under load. I drove it for 5 days and even though it sucked being 200 peak HP again I got no hardware related codes and didn’t notice any power loss or subsequent gain after resetting fuel trims.

2. Flash to Unitronic Stage 2+ (KO4) software and see what happens.

I flashed to Unitronic’s software. The first time I got in the car after the Uni flash to check for neutral misfires I was really nervous. Because if it did still misfire, there was a serious problem and I would be pretty screwed as it would mean this is one of those “chasing a ghost” situations that never gets rectified.

I pulled the car around the corner from my shop and stopped. I raised the RPM’s to 3500-4000. I did not hear or feel any misfires. I jumped out of the car, falling over myself, grabbed my VagCom cable & netbook from the hatch and plugged it in. I again raised the RPM’s to 3500-4000 and watched the counter. I could not hear, feel or log any misfires in any cylinders. Whereas, previously would immediately and rapidly misfire upon raising the RPM’s. As people walking by stopped and stared at me screaming in joy, I ran to the hatch and threw the cable and netbook in the trunk.

Now I got on the road. As I floored it, the car lurched forward and the tires broke loose. The sudden torque and pull was insane. I was completely not expecting it and figured I should probably take it easy. The next thing I noticed was the boost peaks to 21-22psi and holds without falling back. The boost also builds smooth with no flutter and the concurrent power during pulls is strong in every gear.

In short, my car is insanely fast and pulls hard in all gears with no boost fluctuations and most importantly no misfires or loss of power! It’s never been this powerful and smooth and I am still on snow tires; I can’t wait to get the summers on this weekend. What blows me away is that all of those issues disappeared with just the change to Unitronic’s tune. All of the hardware was exactly the same post pre and post software swap. I’ve never had hard torque or pull in 5th gear at 80 MPH. I do now.

Now after all this being said, I could not possibly care any less about the tuner wars and the BS that surrounds it. I don’t yet fully understand how Unitronic’s software fixed my issues, although I did learn quite a bit from John and I also expect that to continue. What I do know is that so far…. it has fixed the issues. Their customer service has been phenomenal and personal. They kept the diagnosis focused on the data & facts and didn’t jump to any conclusions on the cause. John was very adamant that I be 110% truthful in my review, whatever the outcome, and refused to have any input in how or what I posted here. They could have easily planted seeds to nudge my review they way they wanted and I was on the look out for that. Even when I asked a few questions regarding this John kept saying “I want this to be all from you”. It was refreshing and unexpected as ive dealt with a lot of vendors for all different products and many times they will try to influence a review. Not so this time.

So to wrap this up, I’m only as loyal to a vendor as they are to me and as the product works as it should. This is not my first time around the block as the saying goes so I have a fairly good handle on how things should perform. And if this current blissful situation should change, ill post that as well. Anyone who knows me or reads my threads and posts can probably tell that I only put out things based on facts and my first hand experiences and impressions based on those facts. I do not post hear-say and I try and help anyone who asks me for help to the best of my ability. I feel that posting this summary of what I have experienced modding this particular car will do just that.

NEUTRAL MISFIRE TEST LOGS
++ Engine load shows its in neutral (15%-20%) ++
++ misfires under load with subsequent timing pull have also stopped ++​

APR Neutral Misfire Test on March 13 2013:
https://docs.google.com/file/d/0B-RLbVJA2gfocFV2UkVsN3I0Zjg/edit?usp=sharing

VW OEM TUNE Neutral Misfire Test on April 8 2013:
https://docs.google.com/file/d/0B-RLbVJA2gfoMEdSdXg1dzd6OGs/edit?usp=sharing

UNITRONIC Stage 2+ (K04) Neutral Misfire Test on April 13 2013:
https://docs.google.com/file/d/0B-RLbVJA2gfoWWdyczRCaVM0VDg/edit?usp=sharing

See my carbon cleaning before and after pics: http://www.golfmk6.com/forums/showthread.php?t=53613

mdhollis's UNITRONIC Stage 2+ (KO4) Impressions:http://www.golfmk6.com/forums/showthread.php?t=57805&highlight=unitronic+stage

HYDE16's UNITRONIC Stage 2+ (KO4) Review: http://www.golfmk6.com/forums/showthread.php?p=1171828
 
Last edited:

Jeff43

Ready to race!
Great review, Paul and I'm glad this seems to finally be sorted. I've been along with you on most of this journey so I'm happy to see that all the time/money/sweat & tears you've put into your modding are finally paying off....look forward to a ride in it next week! :thumbsup:
 

grambles423

Automotive Engineer
sub'd
 

allset

Go Kart Champion
Sub'd. Amazing contribution to all K04 owners Paul.

thx, Ry.

Great review, Paul and I'm glad this seems to finally be sorted. I've been along with you on most of this journey so I'm happy to see that all the time/money/sweat & tears you've put into your modding are finally paying off....look forward to a ride in it next week! :thumbsup:

yeah, its been brutal man. you can take it out next week

Can I drive it, cant wait to see how she is ruuning with everything fixed.

no u cant drive it b/c its a go-cart compared to your car :D

just kidding, of course
 

Djunited1

Go Kart Champion
Good to hear that everything is sorted. Hopefully mine gets sorted as well.
 

allset

Go Kart Champion
Good to hear that everything is sorted. Hopefully mine gets sorted as well.

thx, i hope you get it sorted too. go bigger on the IC and piping like u said
 

Thunderfunk

Ready to race!
Sub'd also. Glad to see you got this sorted. Ryan had mentioned to me you were going to try this as a last resort. Might be going the Uni route also when they come out with program switching.

Sent from my Nexus 4 using Tapatalk 2
 

dbizzle22

Go Kart Champion
Good to hear! I wonder if reflashing back to stock and then reflashing APR software would have done the same trick. Basically your first APR K04 flash just didn't fully take for some reason?
 

allset

Go Kart Champion
Good to hear! I wonder if reflashing back to stock and then reflashing APR software would have done the same trick. Basically your first APR K04 flash just didn't fully take for some reason?

I thought about that last summer. Ive been reflashed once or twice since July 2012.
 

U-20T

Go Kart Champion
Good to hear! I wonder if reflashing back to stock and then reflashing APR software would have done the same trick. Basically your first APR K04 flash just didn't fully take for some reason?

I thought about that last summer. Ive been reflashed twice since July 2012.

EDIT: I spoke to soon, looks like he tried that and also had a brand new ECU in the middle so that route has already been taken more than once
 
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