All those that use e85!?

WendysOrBust · May 23, 2015

its looking like I might have to but its killing me having to leave it over the long weekend. i have a full tank so im just gonna burn thru it and hopefully it goes out. either way it is a good idea to have it checked at dealer. thank you

Do you have the 6.2 or 5.3? Reason I ask is the 6.2 is not flex fuel, in 2014 ALL 5.3's are flex fuel equipped. HOWEVER, in 2015 flex fuel is an option on 5.3's. Easiest way to check is to make sure your gas cap is yellow.

Yellow Gas Cap = Flex Fuel

Black Gas Cap = Non Flex Fuel

grumps91331 · May 23, 2015

just dropped it off at the dealer. will keep you posted

grumps91331 · May 23, 2015

5.3 yellow cap

Slo281 · May 23, 2015

just dropped it off at the dealer. will keep you posted

Please do!

grumps91331 · May 23, 2015

well fellas looks like the fuel is the least of my worries. Apparently the code was due to the tranny. truck only has about 2300 miles. damn shame. second brand new chevy i purchase with the same problem. 1st one was an equinox back in 2005. tranny had to be replaced. not to sure how to feel about them anymore. on the other hand, love the way it responded to e85 fuel.

joeglock40 · May 23, 2015

What happened to the Tranny?

grumps91331 · May 24, 2015

dealer said they wont know until further inspection but probably wont get an answer until tuesday since their tranny dept is backed up. their was lag, rpm range would get pretty high sometimes before shifting. At first I thought it was due to the change in fuel. Good thing I took it in as I was just gonna burn thru a couple tanks of gas and see if it would disappear but my OCD couldnt stand to look at that check engine light any longer

WendysOrBust · May 24, 2015

Honestly it just sounds like a decective transmission. The 6L80e has pretty good reputation. Glad you caught it early. The good thing is that the dealer will most likely just replace the transmission.

crafferty · May 24, 2015

Honestly it just sounds like a decective transmission. The 6L80e has pretty good reputation. Glad you caught it early. The good thing is that the dealer will most likely just replace the transmission.

+1 these GM truck transmission are pretty damn good. Now that equinox well that was an equinox lol.

grumps91331 · May 24, 2015

+1 these GM truck transmission are pretty damn good. Now that equinox well that was an equinox lol.

grumps91331 · May 24, 2015

wife loved that equinox once the tranny got replaced. Put in about 150000 miles before letting it go. Can't wait to get my truck back.

WendysOrBust · May 25, 2015

wife loved that equinox once the tranny got replaced. Put in about 150000 miles before letting it go. Can't wait to get my truck back.

Btw, out all of the avatars you have been trying the one you have on now is the best one.

Higgs Boson · May 25, 2015

just as an update I am running E85 in my 6.2 now. I have not installed a sensor, just changed the tune for it. The 6.2 on E85 feels pretty damn good!

crafferty · May 25, 2015

just as an update I am running E85 in my 6.2 now. I have not installed a sensor, just changed the tune for it. The 6.2 on E85 feels pretty damn good!

When you switched to E85 did you have to run the tank dry and then fill with E85? How does that work since its just a tune?

Higgs Boson · May 25, 2015

When you switched to E85 did you have to run the tank dry and then fill with E85? How does that work since its just a tune?

For best results, yes. I probably had a couple gallons of 93 in there still but next time I fill up it should be all gone.

How it works with the tune is simple. There is a Stoich table that has different values based on different alcohol percentages (9.8 for E85 to 14.68 for E0 and everything in between) in the Flex vehicles. In my truck, since it is not a Flex, it reads 14.1 (E10) all the way across for all alcohol percentages.

As long as your MAF and VE tables are correct (for your mods or stock if you are stock, etc) then all you really have to do is change the stoich table to match the fuel in your tank. I run it at a value of 10:1 in my Vette since you usually get something around E75-E80 rather than straight up E85 so that keeps the fuel trims in line without having to mess with your airflow tables. Right now I have my truck set to 11 and that trims about 2%, which is nothing. The next tank I will measure it out perfectly to trim -3% by only changing my stoich table (probably to 10 like the vette).

The only other thing you need to configure is spark timing. The Flex vehicles reference a Flex spark timing table to add or subtract timing to the base table based on alcohol percentage. The easiest way to do it is just add that Flex modifier table to your base table. On my personal vehicles, on E85, I also copy the High Octane table (modified for E85) to the Low Octane table so it doesn't lower timing for some reason (you will never get knock on E85, you will hit MBT first, which is too much timing anyways so it is safe as long as you aren't dumb with it).

I was able to get about 18 degrees of timing at WOT on 93 and run about 23-25 on E85. The power increase is very noticeable on the 6.2. On my Vette MPG went from 30 to 20, which is the expected drop. So far my truck is looking like a drop from about 20 hwy to 14 or so, which is the same 30%. Pretty cool.

just as a side note, my kooks headers should be coming in friday, give or take a couple days, so I am excited to see what that will bring.