Help with e85 oft - ltft is very high

[Neos]

Let me start off by saying I'm a complete noob in this area and any help is appreciated.

Switched to E85 this week. All seemed well up until yesterday. Ran down my first tank of e85 - ltft at this stage was +/-10%. Filled up with a fresh batch of e85 and my ltft are extremely high. 10%+, sometimes even below 20%. I took it to the exhaust shop to check for leaks and there was a small leak from the headers which was fixed. Fuel trims stayed the same - above 10%. I then tried reflashing... no luck.

Both tanks were from United e85 from different stations.

Here are some data logs:
https://datazap.me/u/neos/log-152628...og=0&data=1-11
https://datazap.me/u/neos/log-152628...og=0&data=1-11
https://datazap.me/u/neos/log-152628...og=0&data=1-11
https://datazap.me/u/neos/log-152628...og=0&data=1-11

Data logs were done after 50+kms of cruising - no WOT. This was also after the reflash.

I have a K&n drop in air filter and am not sure if this changes ltft especially this drastically.

I am definitely a beginner when it comes to fiddling with ecu - at this point I'm scared to drive the car.

And yes, I double checked to see if I'm running the correct tune. UEL E85 stage 2.

[CSG Mike]

Get a flex fuel kit.

[steve99]

Originally Posted by CSG Mike

Get a flex fuel kit.

In Australia we are lucky our E85 from United petroleum is quaranteed 85% ethanol mixed with high grade petrol it never varies straight from pump.

You dont need flex kit, nice to jave but not needed, different in usa though with variable ethanol content

https://www.unitedpetroleum.com.au/fuel/e85/

[guybo]

High positive LTFT, looks to me like you either have a problem with a vacuum leak or air is getting into the engine post-MAF. It could be the PCV, a catch can leak or brake booster etc. OR, more likely- the exhaust place did not fix the exhaust leak. You need to put a new gasket on the header every time it is removed. If they only torqued the bolts down, they didn't do squat. Also, the connection to the OP, FP and MP all need to be checked.

If the gaskets weren't replaced or if problems are found, take it all apart and replace all the gaskets. You can do it yourself.

IMHO, a FFK in this case would just cover up the problem. I think a FFK is a great thing but if you have a hardware issue, you need to take care of that.

[steve99]

Originally Posted by Neos

Let me start off by saying I'm a complete noob in this area and any help is appreciated.

Switched to E85 this week. All seemed well up until yesterday. Ran down my first tank of e85 - ltft at this stage was +/-10%. Filled up with a fresh batch of e85 and my ltft are extremely high. 10%+, sometimes even below 20%. I took it to the exhaust shop to check for leaks and there was a small leak from the headers which was fixed. Fuel trims stayed the same - above 10%. I then tried reflashing... no luck.

Both tanks were from United e85 from different stations.

Here are some data logs:
https://datazap.me/u/neos/log-152628...og=0&data=1-11
https://datazap.me/u/neos/log-152628...og=0&data=1-11
https://datazap.me/u/neos/log-152628...og=0&data=1-11
https://datazap.me/u/neos/log-152628...og=0&data=1-11

Data logs were done after 50+kms of cruising - no WOT. This was also after the reflash.

I have a K&n drop in air filter and am not sure if this changes ltft especially this drastically.

I am definitely a beginner when it comes to fiddling with ecu - at this point I'm scared to drive the car.

And yes, I double checked to see if I'm running the correct tune. UEL E85 stage 2.

Ok as usa e85 is generally averaged arround 70% or so that what the tune is set up for.

In australia united e85 is 85% hence you running high positive fuel trims to compensate for the higher ethanol content of australian fuel.

If you run united all the time you can just tweak the tune and it will be fine.

Its not going to blow up but it can run better, its running mid 11 afr sgould be mid 12 and high trims but its easy fix.

Just message me