[Tzu]

Sorry, should have worded that better. Decreasing OL scaler will worsen your AFRs by pegging trims at their limit moreso.

Suggest resetting all adaptations and logging a couple pulls. We can have a better idea after that.

If trims are still an issue and you insist on running e85, then you should contact your tuner for feedback.

[NiVeDh]

Originally Posted by GeorgiaTech335coupe

NiVeDh, reset your adaptions and do another log. I'm assuming you are doing 3-4 gear pulls? Try to stay in 4th for as long as you can do it safely. Also, stop with the granny shifting, lol.

They were mostly 2-3 pulls. There's really nowhere in midtown ATL to do 4th gear pulls while avoiding potholes and the cops. Excuse the granny shifting!

Originally Posted by Tzu

Sorry, should have worded that better. Decreasing OL scaler will worsen your AFRs by pegging trims at their limit moreso.

Suggest resetting all adaptations and logging a couple pulls. We can have a better idea after that.

If trims are still an issue and you insist on running e85, then you should contact your tuner for feedback.

Firmware and maps reloaded (even tried the latest maps that were just posted). All adaptations cleared. All instructions followed to the letter. I am not so much concerned about the fuel trims as I am with the fact that the fuel trims for one bank pretty much flatlines at 0%. The car then goes into some sort of weird limp mode, runs rough, sputters, etc. It is essentially not drivable until I restart the engine.

Here is a 3rd gear pull. I can make the issue happen every single time in 3rd. It seems to be getting worse. No good response from Shiv yet - he must be busy. Car runs perfectly in Map 0. I have tried everything. I'm going to stop abusing the car, empty the tank, and go back to 93 octane and see what happens.

[Joshboody]

What's your E%? i was helping someone the other day and they were basically maxed at 30% with conservativish boost and an aggressive OL remap. There's variences in hardware and maybe even procedes.

Go conservative setting, fuel and work your aggression back up. The trim activity is very strange and maybe something other than tuning.

[NiVeDh]

Originally Posted by Joshboody

What's your E%? i was helping someone the other day and they were basically maxed at 30% with conservativish boost and an aggressive OL remap. There's variences in hardware and maybe even procedes.

Go conservative setting, fuel and work your aggression back up. The trim activity is very strange and maybe something other than tuning.

50% E85 with 50% 93 octane pump gas (top tier).

[Tzu]

I'm not exactly sure how the e85 maps function and transition based on E content. Without the fuel flex sensor I assume you have to manually adjust a variable to tell the unit what % of E you're running. The times I usually see this on gasoline, it's usually an adaptation issue that can really crop up at any time.

While I agree with Josh that some cars exhibit issues with E85 to a certain extent and others do not, it may be worthwhile testing on pure 93oct again just to eliminate injectors as the source.

[NiVeDh]

Originally Posted by Tzu

I'm not exactly sure how the e85 maps function and transition based on E content. Without the fuel flex sensor I assume you have to manually adjust a variable to tell the unit what % of E you're running. The times I usually see this on gasoline, it's usually an adaptation issue that can really crop up at any time.

While I agree with Josh that some cars exhibit issues with E85 to a certain extent and others do not, it may be worthwhile testing on pure 93oct again just to eliminate injectors as the source.

These are meant to be run only with 50/50 E85/pump and as far as I know, there isn't one variable that can be adjusted. The car was running fine a couple of weeks ago. It could be a hardware issue of some sort.

I will go back to 93 octane and see what happens.

Thanks to everyone for the help!

[enrita]

Why is SHIV not giving any input here?

[GeorgiaTech335coupe]

Originally Posted by NiVeDh

50% E85 with 50% 93 octane pump gas (top tier).

What was your OL% for that last log you posted?

If it was at 100%, go down in 2% increments and see if it stops. I haven't seen too many STFT shutoffs since I went down to 95%, but my STFTs are higher now.

Yeah Midtown Atlanta isn't exactly the best place to drive fast.

[NiVeDh]

Originally Posted by GeorgiaTech335coupe

What was your OL% for that last log you posted?

If it was at 100%, go down in 2% increments and see if it stops. I haven't seen too many STFT shutoffs since I went down to 95%, but my STFTs are higher now.

Yeah Midtown Atlanta isn't exactly the best place to drive fast.

It was at 90%. I started at the default of 75% and went up in 5% increments - did not make any difference with the shutoffs.

[BmwECY]

procede flash may be able to resolve these issues....

[NiVeDh]

Originally Posted by BmwECY

procede flash may be able to resolve these issues....

If I understand correctly, the Procede Flash helps when your fuel trims are maxed out. In my case, that's not the problem. If I set OL to 100%, the fuel trims are fine (at least for the one bank). The problem is that one bank's fuel trim flatlines at 0% and doesn't want to work. It is stuck in some sort of delayed closed loop fueling mode.

Looks like this guy had a similar issue: http://www.e90post.com/forums/showthread.php?t=641682

[NiVeDh]

Shiv said he has experienced something similar and that it could be a failing O2 sensor. Mine have 61K miles on them so I am going to go ahead and replace them. I'll update the thread afterwards.

[enrita]

so suddenly many 02 sensors are going bad? Any 02 sensors codes?

[Joshboody]

Could be the DME is perceiving an issue with an O2 due to the lean readings and its going into OL mode exacerbating the situation. Before changing hardware I would reduce E% and up the OL mapping (maybe I'll post a map with upped mid-range you can copy). When reducing E% you kinda need to richen the mixture also, but if you keep boost conservative I think its ok.

[NiVeDh]

Just noticed today that one bank randomly leans out during idle too. Hopefully, the new O2 sensor takes care of it. I'll post an update in a few days.

[NiVeDh]

Before I spend a lot of time replacing those O2 sensors, I ditched E85 and decided to go back to 100% 93 octane gas and here are some logs.

The car runs perfectly and consistently in Map 1 at the default boost settings.

On map 4 (meth on and boost turned up a tiny bit), the issue came back. In the middle of the run, the AFRs shoot up very lean and the car goes into a limp mode.

I hope replacing the O2 sensors fixes everything... we'll see.

[The Ghost]

I don't think it's the sensors, I think it is something in the tune. Perhaps too much AFR bias, I don't know. It doesn't happen stock in a lower power map.

This only happened for me when I loaded a friend's map. I slowly tuned my map so that the OL fueling map was progressive (from low boost to high, left to right on he graph). I did this cell by cell until this stopped happening.

This is one of the things I'm hoping the procede flash will get rid of. I've only had the flash for a few days so I can't comment either way.

[themyst]

Originally Posted by NiVeDh

Shiv said he has experienced something similar and that it could be a failing O2 sensor. Mine have 61K miles on them so I am going to go ahead and replace them. I'll update the thread afterwards.

Your O2s are NOT going bad. Drop it to an E33 mix or so (5 gallons E85), run 100% OL and log it again.

[jpirelli]

Originally Posted by themyst

Your O2s are NOT going bad. Drop it to an E33 mix or so (5 gallons E85), run 100% OL and log it again.

His last logs were 93 octane apparently.

I agree it's not the O2s. Sometimes it's the bank 1 and sometimes it's bank 2 that goes wonky so what are the chances that both of your O2s are going bad at the same time?

[themyst]

Originally Posted by jpirelli

His last logs were 93 octane apparently.

I agree it's not the O2s. Sometimes it's the bank 1 and sometimes it's bank 2 that goes wonky so what are the chances that both of your O2s are going bad at the same time?

Piggyback AFR is a calculation, not actual. If his O2 sensors were actually going bad, he would be throwing lambda-related codes. Here's an idea, disable CANClear and see if any lambda-related codes pop up within 100 miles. If not, it's 99% of the time, tune related and not hardware.

The easiest thing to do would be to datalog/monitor AFR using INPA or a BT cable, or even install a Cobb AP simply to rule out hardware.

[cn555ic]

I had once had a wacky reading with my a/f during idle as it was registering close to 16-17. I shut of the car and turned it back on and the readings were normal again. I also reloaded firmware to be safe. It has never showed its ugly face again.

[themyst]

Originally Posted by cn555ic

I had once had a wacky reading with my a/f during idle as it was registering close to 16-17. I shut of the car and turned it back on and the readings were normal again. I also reloaded firmware to be safe. It has never showed its ugly face again.

Makes me believe there is a bug in the AFR calculation. It's no coincidence a large group of people are having the same issue at once.