True Flex Fuel Tune

[engineermike]

I have not had any luck going from 100% to 100%

I always need to do a KAM reset. I usually start blending at 1/4 or 1/2 tank levels. This helps the computer learn.

I tried 40 on the time and counts but it needed several miles of interstate driving to mature.

I lowered the refill threshold to 5% to make sure it starts a relearn when I add gas.

It’s already learned to 30% in 8 miles. Even if it locks in here it now will be fine because the timing “toggled off” at 55%. Learned afr is 12.8 at 30% learned alcohol so fuel trims can handle it from here.

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[K4fxd]

I lowered the refill threshold to 5% to make sure it starts a relearn when I add gas.

10% is just 1.6 gallons.

Learned afr is 12.8 at 30% learned alcohol so fuel trims can handle it from here.

I think the system works because of the wide range the computer can deal with.
I'm just a bit OCD

 

[WildHorse]

So basically you guys enjoy running lean which can melt your pistons, or run rich and wash your cylinder walls.

 

[K4fxd]

 

[WildHorse]

No seriously. It seems like that's what yer doing. I'd take a hard pass on that all day long. also if yer relying on the PCM to make up a 30% discrepancy, that's just askin for trouble. Shouldn't take 8 / 20 / 30 mins to determine E-content. Latency is a engine killer. Yer using yer using yer own tables to 'predict' content for 'x' amount of time. What do you think is happening in the interim ?

 

[engineermike]

10% is just 1.6 gallons.

I put 2.5 in one time and it didn’t trigger a relearn. The pcmtech table explains why I think. Either way, you shouldn’t have to clear the kam to make it relearn.

I think the system works because of the wide range the computer can deal with.

A 20% “error” in alcohol is only 10% in the fuel trim. That’s not too bad depending on how you have the timing set up. I think that’s passable but I also don’t think I’ll wind up with that much error. It’ll probably settle out around 15% alcohol.

 

[K4fxd]

Mine has never locked in over 10% on the trims.

I'll look at the PCMtec fueling tables. I got pissed when they deactivated the Australian version of the software.

 

[K4fxd]

The pcmtech table explains why I think.

The new American version has 16 less ethanol parameters than the Aus version. I still have an open copy on a computer that is not connected to the internet.

I wasted my money

I see several that would help it learn content that are gone.

 

[engineermike]

@K4fxd pcmtech has a table the floats the relearn refill % as a function of learned afr. So I don’t think it’s just the dumb scalar % in hpt.

@WildHorse you have widebands with STFT, LTFT, and learned stoich lambda. A/f ratio is handled well and very fast I could show you the log with fuel trims going to -20% and with 20% alcohol error yet measured lambda is still 1.0+/-.02. Running rich or lean isn’t the concern here.

 

[engineermike]

Shouldn't take 8 / 20 / 30 mins to determine E-content.

The pcm learns much faster than it takes the fuel lines to purge.

 

[K4fxd]

PCMtec needs to be connected to the internet to get the bootloader. At least the first time. My old version is worthless.

I just got the tactrix today and it is 32 bit and the version 3.10 is 64 bit. I have a ticket in to see how to make it work.

I checked on the russian tuning software and it looks to be bricked.

 

[junits15]

So basically you guys enjoy running lean which can melt your pistons, or run rich and wash your cylinder walls.

You are never running rich or lean unless you were to totally max out the fuel trim or introduce an exhaust leak in the headers. If you're seeing +30% its telling you that your base fuel targets are off by 30%. It doesn't actually represent a dangerous situation.

Its lambda targeting, no mater what fuel you put in, if it targets a lambda of 1, it will just add enough fuel to hit that target. On gasoline the sensor reports 1 λ at an AFR of 14.7:1, on e10 it reports 1 λ at 14.01:1 on e85 it reports 1 λ at 9:1. The computer adds or subtracts fuel as needed to hit 1 λ (or some fraction of 1 λ ). That's what your trims are.

No seriously. It seems like that's what yer doing. I'd take a hard pass on that all day long. also if yer relying on the PCM to make up a 30% discrepancy, that's just askin for trouble. Shouldn't take 8 / 20 / 30 mins to determine E-content. Latency is a engine killer. Yer using yer using yer own tables to 'predict' content for 'x' amount of time. What do you think is happening in the interim ?

In the interim what happens is your absolute fuel trims are large.

Dangerous knock is prevented by the KR system (provided someone doesn't deaden the knock sensors or massively jack up the ramp rate.)

 

[junits15]

PCMtec needs to be connected to the internet to get the bootloader. At least the first time. My old version is worthless.

I just got the tactrix today and it is 32 bit and the version 3.10 is 64 bit. I have a ticket in to see how to make it work.

I checked on the russian tuning software and it looks to be bricked.

I found this for you, the instructions for 32 bit are here.

https://pcmtecgeneralstorage.blob.c...=bb+HHexNU7mMuxNlVWWRf3KdSdQYUfb5uogy0T84obY=

The new American version has 16 less ethanol parameters than the Aus version. I still have an open copy on a computer that is not connected to the internet.

I wasted my money

I see several that would help it learn content that are gone.

This is awful news, what did they take from us? This seems like it could be more than just emissions stuff, maybe those parameters were wrong?

 

[K4fxd]

This is awful news, what did they take from us? This seems like it could be more than just emissions stuff, maybe those parameters were wrong?

I uninstalled and downloaded it again today, the lost ethanol parameters are back. Still can't turn off FAOSC with a switch.

The newly downloaded version is x86 and works with my dongle.

 

[junits15]

I uninstalled and downloaded it again today, the lost ethanol parameters are back. Still can't turn off FAOSC with a switch.

The newly downloaded version is x86 and works with my dongle.

Just out of curiosity what parameters did you temporarily lose? I'm curious if mine is working right

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