How to run E85 on stock 86 BRZ FRS with OFT tune

[Strife26]

Originally Posted by perry753

Love using E85 so far. Propel in the bay area offers a gallon for $2.20-2.30 currently.

Must be nice. $6.50 here because only one place has it and it's a fuel store not a gas station.

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[steve99]

Originally Posted by nelsonzep

I did this correctly as you have stated but after about 20 miles on e85 tune driving under 3500 rpm i get check engine light and p0171 too lean code. also after about 40 miles the ltft is still around 35% and hasnt gone down. I currently have 02 spacers on my headers could this be causing the problem? i read that it is either 02 sensor/ maf sensor failure or leak in exhaust/intake? but could it be my spacers?

You dont need 02 spacers as the tune disables the cel code 0420.

Hopefully the o2 spacer is only in the rear (second o2 sensor)

Having an o2 spacer in the front 02 sensor is very bad and will cause severe issues on petrol or e85 as thgis is the main sensor for afr, never put an o2 spacer on front primary sensor.

Is your intake stock ?

do you have an intake or exhaust leak ?

35% fuel trims os abbout what you would expect to see if you flashed a petrol tune by mistake check you flashed the correct tune.

[nelsonzep]

Ill check the spacers today and the tune. Intake is st performance its just a drop in filter and pipe that deletes the sound generator if this is effecting it what would i need to do to correct it?

[steve99]

Originally Posted by nelsonzep

Ill check the spacers today and the tune. Intake is st performance its just a drop in filter and pipe that deletes the sound generator if this is effecting it what would i need to do to correct it?

If the stock air box and maf housing is still used it should be fine.

[jaorocks1]

How many gallons of 91 can I put into a full tank of e85, I've been having trouble with cold start at 40-50 degrees

[steve99]

Originally Posted by jaorocks1

How many gallons of 91 can I put into a full tank of e85, I've been having trouble with cold start at 40-50 degrees

Best option is to modify the Cranking IPW (Injector pulse widths to inject more fuel) using romraider. see tables below

or you can add a gallon of petrol, best to use 93 if you have it but 91 will do.

[nelsonzep]

Well there is no o2 spacer in first o2 but second has one. Re did the tune and drove about 30 miles the ltft is still at about 27 and goes down to 20 everynow and then but not lower

[steve99]

Originally Posted by nelsonzep

Well there is no o2 spacer in first o2 but second has one. Re did the tune and drove about 30 miles the ltft is still at about 27 and goes down to 20 everynow and then but not lower

Looking like an air leak in exhaust (or possibly intake). did you ever check LTFT when you were on petrol ? was it also high ?

If you have exhaust leak arround first 02 sensor overpipe or at header to engineblock junction the sensor sees bursts of fresh air. This contains a lot of oxygen so the ecu thinks the car is running lean, so its adds heaps of fuel (ie high positive LTFT). trying to correct the perceived lean condition.

Can also happen with intake air leak

[nelsonzep]

The lt and st % were normal during 93 tune ill check for exhaust leaks later today and intake leaks to make sure thats not the problem

[steve99]

Originally Posted by nelsonzep

The lt and st % were normal during 93 tune ill check for exhaust leaks later today and intake leaks to make sure thats not the problem

Hmmm thats weird. If the LTFT were way under 10% on petrol it would indicate you dont have any leaks.

Is possible if on petrol you were say +8% or so and then if your on very high ethanol content fuel like E90 then you will go even further positive probably in the +15% range. But over 20% is strange.

what do the actual AFR look like is the afr close to the open loop fueling table under load

That sort of level usually indicates a problem like a leak or your on a petrol tune with E85 in tank.

[nelsonzep]

I'm not sure what the open loop fuel table is but my AFR bounces between 14 and 15, it usually stays at 14.6 at cruising speed. I also have all light weight engine pulleys and idlers will that affect anything? I currently have an O2 spacer on the rear O2 sensor, I'll take the spacer off when I get home and see if that changes anything and reflash the tune to make sure it's e-85.

[steve99]

Originally Posted by nelsonzep

I'm not sure what the open loop fuel table is but my AFR bounces between 14 and 15, it usually stays at 14.6 at cruising speed. I also have all light weight engine pulleys and idlers will that affect anything? I currently have an O2 spacer on the rear O2 sensor, I'll take the spacer off when I get home and see if that changes anything and reflash the tune to make sure it's e-85.

On E85 you should be seeing arroud 14 at cruise 13 as you accelerate and down in the low to mid 12 under hard acceleration higher rpm.

[steve99]

Originally Posted by nelsonzep

I'm not sure what the open loop fuel table is but my AFR bounces between 14 and 15, it usually stays at 14.6 at cruising speed. I also have all light weight engine pulleys and idlers will that affect anything? I currently have an O2 spacer on the rear O2 sensor, I'll take the spacer off when I get home and see if that changes anything and reflash the tune to make sure it's e-85.

You intake is stock except for filter and intake tube ie the maf sensor and airbox is stock correct ?

If your drop in filter is an oiled filter it may be worth cleaning maf sensor with some maf sensor cleaner in case it was over oiled and oil has got on sensor

[nelsonzep]

yes the air box and sensor are both stock and i cleaned the maf when i removed the first 02 spacer this morning. i am home now and took a couple of logs i can upload and share just give me a minute.