drothgeb

I wanted to share with everyone my 82mm TB lean condition issue experience. I have a 30 mile drive to work in rolling hills and would consistently get it twice a day, to and from work.

I'd gone down the rabbit whole to try to find a fix for this and had zero luck. Things that I tried:
Smoke leak checks
Different TB
Different intake
Altering the crankcase vents to increase engine vacume
Introducing various sizes intake leaks to decrease engine vaccine
Switched EC to RIQ tunes and back
Build various size filter circuits onto the map censor with capacitors zlsized from 1pf to 1uf.

In preparation for potentially going to a blocked off bpv I purchased a DTK tune (he's the only remote tuner that told me he can tune for it and has experience with them).

Put on DTK tune, no other changes, hiccup gone.

I don't want to say this will work for everyone, but there has been some threads over the years where folks had said they believed it to be 100% tune related and German tuners didn't have this issue. I believe that to be the case as well.

lost27

How long have you been running the DTK tune?
Were you getting the P0106 code on your drives?
What is your throttle position % at idle/park?

I'd be curious to hear what is different in the DTK tune. In the older threads it seemed like BIP tune would fix it. Anthony Lawshee used to tune at BIP and now tunes at RaceIQ so I'm bummed to hear that the RaceIQ tune didn't help.

hachiroku

that is quite a lot of money spent on tunes.

Pieter Schepers

How does the tune feel power wise? Can you PM me the contact info of DTK?

SICAMG

DTK told me the same thing months back that they could fix it. Interesting.

lost27

I'd be curious what they are doing differently than everyone else.

drothgeb

I've been running it for a little over a week now. Also switched back to RIQ one day to check, lean condition both to/from work. I was getting P0106 yes. Don't know what the throttle percent is at the moment I haven't checked in a bit but if you're refering to the TB open percent check in star to determine if there is unmetered air I've always been in spec (like 1.5%? I can't remember)

It's been over the course of a few years haha. My first tune was EC, then when I wanted to try a fixed pulley EC told me they didn't tune for it so I bought a RIQ tune because he did. Then when I started thinking about playing with blocking off the BPV EC & RIQ can't tune for it but DTK said he could so I went ahead and grabbed his tune when I saw a sale come across haha.

It's fine, all the box tunes are what ever. Maybe get lucky with one over the other but to get the best out of any of them you'll need to log and adjust. DTK has been good about adjustments, usually within a day. I've already had two adjustments to get my AFR where I want it and he's been good to respond. Getting the initial tune was a little slow though. I think he only does business through FB: https://www.facebook.com/demetre.taktakishvili

Yeah, wasn't even thinking about it at the point I got the tune! I was busy building various smoothing/low pass filter circuits to put on the MAP sensor to see if it had anything to due with signal noise or turbulance from the TB maybe I could clean the signal from the MAP a little. Anyways I put the tune on just to get a base line as to where it was sitting with timing and fuel, and no ****ing hiccup lol. Ripped all the crap I had been playing with out, and still no hiccup. Several hundred miles, no hiccup. And like I said I have about a 40 mile drive to work 70mph rolling hills and would get it every drive, never fail.

SICAMG

Im really happy for you man. You just solved one of the biggest mysteries with this problem for many many years.
Still would like to know what the ECU did not like seeing to trip up and respond like it did.

cnterline

Are you running a clutch or fixed ? ,that’s pretty kool if this has finally been fixed for both, I never experienced it but have been reading about it for years ,

C32owner

Happy to hear you got your issue sorted with just a tune. I'm interested in your exact "hiccup" condition that you getting. I'm currently running a Raceiq tune as well, car feels really good and strong, however I also get a hiccup/stall/hesitation, I'm on stock TB however, and my condition occurs at low rpm let's say around 2000rpm and then go to overtake or want to speed up without mashing the loud pedal, so maybe go to slight boost but going from that low throttle cruising input to opening up ever so slightly, not engaging kickdown at all, the is this horrible dip, almost like the old days where people complained of the torque converter locking up at about 1500rpm.. Is yours similar as I'm prepared to switch to dtk to see if this sorts it out too. I also been with EC tune as well.

lost27

@drothgeb What do you get for you LTFT1 and LTFT2? With the 82mm throttle body I noticed that I'm getting -9.2 on bank 1 and -10.2 on bank 2. Have you been able to ask DTK what they did with the tune to handle that hiccup? I thought that most tuners tuned for open loop conditions on these cars not closed loop so I'd be curious how they are able to tune out the hiccup since that seems to occur during closed loop operation.

drothgeb

Thanks! I kind of stumbled on it by accident, but yeah the DTK tune did it for me, hopefully there is something in there that has actually resolved it and will for every one else as well and it's not just a lucky chance that soemthing worked out for my car.

Clutched right now. I never had the issue when I ran fixed myself, but I feel like I read about others that did.

Mine is not the hiccup I believe you're referring too. I think your has to do with the bypass valve and clutch operation. I have pretty much always experienced that as well. I pretty much chalk it up to spinning the super charger fast so it makes the transition from SC clutch disengaged and/or bypass open to clutch engaged/bypass closed a little more violent. The 82mm TB hiccup actually seems to switch the car to some backup tune/map and for modified cars is super dangerous. I hit like 16 AFR WOT lol. Just have to stop and turn the car off then back on, if you want to go WOT. I always have STFT up because they will start bouncing to like 25% when it happens, but usually you can feel it, just a random small hiccup at freeway speeds usually when cruising steady and hit a slight up-hill.

They tune for closed as well. I assume they are trying to correctly estimate and tune for new volumetric efficiency as well as scale injector size correctly just like any ordinary tuner would do, which would keep LTFTs closer to zero. My first tune from DTK was at about -15 both banks, I let him know on one of the retunes and down to -9ish now. I don't really care that much about it but mroe importantly he has responded well to the open loop requests I've made very quickly and gotten me settled in at an 11.5ish AFR. I haven't asked him what he may have done to resolve the lean condition, just mentioned that it did and told him thanks. I don't care to pry as I would imagine if he's the only remote tuner currently resolving it he'd probably want to keep the solution to himself for business purposes anyways.

lost27

What are you using to log your AFRs? I've only got logging via the Torque Pro app but might invest in something better to keep an eye my AFRs.

drothgeb

AEM wideband. Just keeping an eye on it most of the time but have a serial output hooked up for when I want to connect to to my laptop and get a proper log (changing up to DET3 soon with proper analog input from the wideband). Also, as for the fuel trims being a bit off, I have a high compression motor, and run in an area with an average DA ranging from 5000 to 8000ft, so it's a pretty fat chance for any of these tuners to have everything good for my build on the first try.

Sam.P

I fought that damn hiccup / lean condition for over a year, I was running a 82mm throttle with a 168mm crank. Took the supercharger apart 5 times looking for any signs of vacuum leaks and what not, nada. This summer I upgraded to a 180mm crank and 550cc injectors with a remote tune from Tony @ RIQ.

Following the upgrades, the hiccup / lean condition went completely away. Prior to that I was able to trigger the hiccup on demand as I knew exactly the condition that would cause it while driving.

FunkTron

For those that might come across this in the future, how would you replicate the problem?

Sam.P

I was able to constantly replicate the hiccup when slowly accelerating while going uphill at ~60mph. That was the easiest way to trigger that lean condition.
I was so used to it that I could give the exact throttle% to trigger it within seconds. The only way to return to normal “fuel mapping” was to pull over and turn off the car. It wouldn’t always set a check engine.

It would basically trigger when given a certain load% at a certain RPM range, mostly when going 55mph+. Never happens when going WOT or while feathering the throttle.

I’m so glad I was able to get rid of this mysterious issue...

lost27

Could you post up what you see for your LTFT and STFTs with your RaceIQ tune?

drothgeb

Interesting. I haven't come across any other reports of switching to RIQ and/or EC that had their lean issue fixed by the tune. Hopefully mine isn't just a one-off, got lucky with DTK kind of thing and it actually does resolve it for more folks. I know personally my RIQ tunes still hiccup/lean MAP without fail.

What are you so stuck on fuel trims for haha. STFT is useless to look at unless you are making sure you haven't gone into this lean condition, and LTFT is going to be different for every one based on tune, mods, altitude/conditions, etc. Look at YOUR LTFT and if they are off notify your tuner and ask for a new tune if thats what what tickles your fancy. Or pay attention to the important things like AFR and timing and work to get the most out of your tune with who ever you are using.

Sam.P

There are definitely a lot of variables here though. While I’ve kept my 82mm throttle, I changed the crank pulley, s/c pulley plus the injectors. Running much more boost, could be a combination of all the changes that made it work somehow...

Issue is definitely gone as my daily commute is the same and it hasn’t happened ever since. I’ve tried my best to try to replicate the issue but the car just seems happy the way it is.


I wish I could! I will post them when I get back my rebuilt transmission

lost27

I'm stuck on LTFT since I'm trying to get a better understanding of what ballpark normal is after going to an 82mm TB, not so much related to the hiccup. For example, some folks have had their LTFTs in the -5 to +5 where I'm usually down around -8 to -9 on both banks.

With regards to the STFTs, I've seen my car regularly hit highs in the +19-20s without hiccup. My car has gone through three throttle bodies and spent a little over five months in the shop trying to get rid of the hiccup/P0106 issue. I got it back in May and since that time and almost 1000 miles, I've only had a hiccup twice with the most recent one throwing the P0106 code. I've also seen my STFTs hit +25 on a couple of occasions but when I come to a stop or idle, it doesn't have the lumpy struggling idle associated to the hiccup. I'm running a custom Eurocharged tune and it has been much better since the third throttle body but I don't feel it is quite perfect yet. It was great for a few months but I suspect that the car eventually adapts and the hiccup might return.

I've also been having a difficult time replicating the issue in a consistent manner. All the spots where I used to trip the hiccup no longer work, it seems like it is almost random when it happens.

Would you mind posting a pic of your AEM wideband setup? I'm leaning towards going down adding a wideband guage.

MSG 55G

I’ve ran DTK with my fixed 68 pulley and 82 TB and it ran just fine. I’ve recently swapped to 92TB and blocked the bypass valve and started with RaceIQ tune and felt hesitation so I swapped to V-Tech and it still felt boggy with hesitation. I did meth as well so I’m looking into possibly fuel, fuses, relay, and possibly injector o rings. I’m not getting any code, however If I Cold start, it’ll idle rough and run like crap, don’t even want to run, feels like the engine wants to stall. But if I turn it to position 2 and wait 5-10 seconds it’s good.

C32owner

What boost are you seeing now with your upgraded crank and sc pulley combo? I'm am suffering this lean/fail over map issue at the moment, and I was convinced it was after doing a WOT pull and peaking over 17psi threshold which throws the car to lean map, and same thing I have to pull over turn car off and on again. We winter now with high pressure so I can trigger this lean map every WOT pull basically. Now you got me thinking however that maybe it's coincidence and not a 17psi WOT pull but in this 55mph zone you speak of that trigger it. I need to go investigate that further.. So you say 55mph slight uphill and what throttle % trigger it for you?

C32owner

And so there is 3nother gents in here that have suffered from this lean map issue, and you are all getting a P0106 codw thrown? When it throws the code do you get the engine light on as well? Interesting as when I get the lean map condition, which I am suspecting it's an overboost cause, I don't get any engine light or code thrown.. I can only tell by looking at my afr when going WOT. obviously power is down as well but... I don't look at my STFT but maybe I should check out that as well when it has gone lean map condition as you guys seem to report when in that lean map your STFT goes +25?

SICAMG

Like I said C32....If you are close or over 17psi than you will trigger lean condition and will stay until you cycle key. No engine light either.