Can I convert to flex fuel?

[JUSTASBC]

I will be running E85 in my truck very soon, but most of the time I would like to run E10 regular gasoline. I was thinking of switching tunes when I make the change of fuel(basically back on forth on the days I go to the track). I see that there is a fuel sensor GM 13577394 that might work if I knew how to wire it in. I have been unable to find what I need to know to make this work. What exactly do I need to do? It appears that some vehicles calculated an estimated alcohol percentage in the fuel through sensors. I am not sure that I can make this work as I am running without a MAF. I am running the COS in my sig. Any help would appreciated.
Thanks,
Daryl

[cyipher]

intrested in doing this for the older 02-03 style pcm too...

[JUSTASBC]

What is your OS? I found a flex fuel version of my OS. It looks like I can flash it in and run the wire to pin 56 of the blue plug. The sensor takes a neg, 5v, and the wire that returns to pin 56. I am learning more abiut this, and will hopefully be able to give good info about this.

[ls2ss]

This is a good idea. Can any one tell us if it possible to run the sensor to run e85 on the earlier type ecm's.

[JUSTASBC]

I have changed everything to make this work at the end of last year. My alcohol sensor is properly reading the percentage, and everything appears to be working. I have everything but the good weather to try it out, I even have the E85. I actually dont see why this wont work. I found a flex fuel version of my OS, but I am not sure if you could make this work with just enabling the tables.

[Taz]

intrested in doing this for the older 02-03 style pcm too...

2002 Gen III truck used a 512Kb PCM.

2003 Gen III truck used a 1Mb PCM.

These are not the same ......

[Taz]

This is a good idea. Can any one tell us if it possible to run the sensor to run e85 on the earlier type ecm's.

Flex Fuel was available in some trucks in 2002 (512Kb PCM). Look for a tune from an L59 5.3L engine (these were Flex Fuel). Typically the OS is 12216125 - and could be DBC or DBW.

[danny68ss]

Did you get the flex fuel working im trying to get it to work on my 04 looks like all the tables are there i put the sensor on and it has voltage going to the pcm but im not seeing it on the data log

[danny68ss]

this is my flex tune

[JUSTASBC]

Yes, I have this working perfectly. I did a segment swap of an E85 version. I can fill up or even a half tank with E10 or E85, and it automatically calculates what I need. I can also log the ethanol % change.

[danny68ss]

Can you look at my tune to see what im missing

[JUSTASBC]

Sure. Email it to me if you want. Dwrobb99@yahoo.com

[Taz]

... I did a segment swap of an E85 version ...

Nicely done - as you discovered the Flex Fuel version of the same OS is very different.

[danny68ss]

So my pcm will read my sensor just need to do the swap?

[Taz]

Can you look at my tune to see what im missing

Your original tune was not a Flex Fuel variant - so you are missing the Flex Fuel parameters (all of them).

Changing the Flex Fuel parameters visible in EFILive is not sufficient to enable Flex Fuel calculations on a non-Flex Fuel calibration.

[danny68ss]

Ok just found a l59 with same os and did a segment swap engine calibrations is that what i needed

[JUSTASBC]

That should work. I saw a flex fuel version for a Tahoe.

[danny68ss]

Thats what i found too engine segment is what i need isn't it

[danny68ss]

Thanks it works now

[joecar]

Good job :cheers: