2015 Malibu 2.5l can I enable flex fuel

[davez28]

I have a 2015 Chevy Malibu 2.5 liter na. I just read it for the first time and I noticed everything was in there for flex fuel but it's not enabled. Does anyone know if I could enable it and run flex fuel?Of course I would have to use the virtual sensor. I just installed an actual sensor on my truck is that possible to do on this Car too? I've heard a lot of other vehicles the only part that is difference is the yellow gas cap. I don't know if the flex model would have larger injectors and fuel pump or not

[TownDrunk]

I converted my '12 Chevy Volt to use the sensor. Even tho a buddy's '12 had the wire to the ECM, I had to run a new wire for mine.

If it runs with sensor set to physical, you're ready to start tuning. If it doesn't run, see this thread: https://www.hptuners.com/forum/showt...2012-Cruze-Eco

Virtual set to 60Hz = E10, 120Hz = E70.

You could get by with just setting Stoich to match your fuel.

[davez28]

Thanks for the link. Do I have the same ECM in my car? How do I identify what ECM I have? Most of the tables look like they're already set up at my tune. With the exception of the flex spark tables. The stoich table has values for flex fuel

[TownDrunk]

Open your VCMSuiteInfo.txt file, located in Documents\HP Tuners\Logs and Tunes. About a third of the page down, it'll say ECM:

The Volt has the E78.

[davez28]

It's a e39a

[TownDrunk]

On our E78, changing the first value for Stoich AFR to a higher value, say for E50 or E70 would get you fueling for upper ethanol blends.

If you have the sensor, it would pick the stoich value for you.

[davez28]

On our E78, changing the first value for Stoich AFR to a higher value, say for E50 or E70 would get you fueling for upper ethanol blends.

If you have the sensor, it would pick the stoich value for you.

I'm probably not going to do it unless I can find out If can add the sensor for sure. We don't get very consistent blend in my area. I fought with the virtual sensor in my truck and it was always off. Once I added the actual sensor it worked great. I'm pretty sure there are Flex vehicles used in the same ECM as mine. It's just a matter of figuring out which pinout I need to tap. The stoich table is already set up in the tune.. looks like all would need to be done is to turn on the sensor and set up the spark tables.

[davez28]

I would think with 11.3 to 1 compression ratio there could be some performance to be had with a tune. I don't want to tune it and be stuck running 93 octane all the time. What I'm wanting to do is get it dialed in on 87 and then get it running a little bit harder on the E85 side.

[TownDrunk]

We tuned the HO spark table with E10 and dropped the timing a bit more and copied to LO.

Then we tuned the HO table with one guy using 93 octane premium (his choice) and I used E50. Once that was done we moved to E70. We set the FF multiplier to not increase timing until > E50.

Then due to major changes in cam timing, we've started over. We started by copying the intake cam to exhaust cam, got better mileage, then played a bit with maximum timing for both intake and exhaust tables and still got good mileage. Then added a bit more torque from 1400 (minimum idle) to 1900 to quickly get to a low rpm below 60 mph (for max mileage), even with the motor generator trying to charge the HV battery. Then adjusted the cam timing for more power for 3000 rpm and higher and more torque for 1900 to 3000. So far we're getting about 49 mpg highway and 41 city, not bad for a vehicle rated at 37 mph highway with 91 octane premium.

When we get lean cruise (1400 - 1800 rpm) working properly (leaner, but with more spark timing) in the next week or two, we hope to cross the 50 mpg barrier. We had lean cruise working well, but since it lacked proper spark timing, the engine rpm would hunt for more power and rpm would fluctuate about 200 rpm.

Bear in mind injectors, MAF and volumetric efficiency were tuned last year so we already have that incorporated in our tune. That was good for about 2 mpg increase.

Also, although I had a couple years of automotive tech in the 70's and tore apart many engines during that time, I'm still learning to tune. At this time, Laz is the principal tuner on our project.

[davez28]

That's pretty cool

I've had hptuners for over 15 years and I'm just now getting at least some kind of idea how to use it. I got fed up with bad paid for Tunes and bad advice from others so I finally decide to spend some money for some training.
My truck now runs better than it ever has and at least I know the things I modified and the risks and benefits of it
it kinda has me hooked and I want to learn more. Looks like these new 4 cylinders are a bit different than my Gen 4 truck so I'm just trying to do a little bit of studying before I dive in..