I don't think issues with E85 in cold weather are unusual. My understanding is that it's just more temperature sensitive to the cold (I've never messed with it myself). Your tune was likely off a little to start with and the cold made it worse, and then add a faulty temperature reading.
Well E85 is harder to start in the cold, it's why they add more gasoline the the mix in winter. Now the weather is colder the fueling has to be better and you are hitting parts of the starting fuel maps you weren't hitting before. Also an engine can hold heat for quite a while, can take 5-10 hours to fully cool down depending on the weather.
I do fully understand what was said by both of you. What I don't fully understand is why the thing started and ran good on E85 almost from day one up untill the outside temps got down in the lower 50's and then only on first starts if was sitting for more than 10/12 hours.
So maybe I should have said" Cold weather starts "
Sorry about the repost. I am in the middle of about four things and checking on the laptop when I can. So my best bet is to switch to gas for the winter, go to E85 when it warms up and work on/correct the tune in the meantime?
And yes eXo3901 it ran great before it got cold on gas and on E85 both. It made a bit more power, some HP and much more Torque on E85. It is an oddball to tune with it being an E40 EMC. I had hard time finding information about tuning it, what with it being a cross between a Gen3 and a Gen4. Makes it hard to take tables from other tunes, but it dose allow some other things to work that don't work on other EMC's
BigTuner I went in to closed loop early was to force it to a Lambda of close to 1/1.05 because it ran better there then it did if it was richer. I am sure there are better/correct ways to do the same thing but at the time all I needed to do was get it so I could drive the damn thing.
At least try populating FlexFuel base corrections.
E85 range is 51-83% alcohol. Cold weather blends have lower ethanol content. You shouldn't be having problems.
One thing that's confusing me is your sig says Nebraska. It's not that cold there so how are you even testing this?
What's the point in all this exactly? You're and I are both in the "corn belt" and e85 still isn't priced low enough to offset the lower energy content. With a TBSS you want premium octane, correct? The sweet spot is e35, which is 91 octane. Get an e85 blend calculator on your phone and mix it at the pump. You'll have to guesstimate the ethanol content you're blending due to the possible range of e85, but that's what your ethanol sensor is for. Mixing to get e30-e40 is way cheaper than the price of premium gas. You'll also not have to deal with your full e85 cold start issues.
Last edited by SiriusC1024; 11-11-2022 at 06:35 PM.
SiriusC1024 as of right at this moment 12:30 am it is 15 degrees outside and I had started my truck up an hour ago to come to work.
Local blend is running around 75% alcohol I had blended down to around 60% to see if it helps. In my area E85 is around 2 bucks lower then 91 octane and I don't use that much more on E85 then on 91 octane.
With my setup it runs significantly better on E85 then on gas.
I do see what you mean with populating the FlexFuel base correction tables. I guess you mean fuel and spark?
SiriusC1024, I populated my FlexFuel spark tables today and said " f**k it " and put around 10 gallons of E85 in her today. That put my Ethanol percentage at 69% and in winter the best we can get is going to be is maybe 75% around here.
I just went out and started the truck and it fired up better then ever has on E85 in cold weather. This at 3am in 16 degree weather. It failed on the first crank but on the second on it started almost like it dose when it is warm out. After looking at the log I see that it did not pull the timing way back on the first crank but it did on the second.
I know I need to work on my fueling especially at start up. But just getting it to start a little better is something. I really do appreciate the help. I did forget to change my closed loop enables, that will be something I will correct on the next flash.
Once again I appreciate the help. And as I move forward with this I hope I can continue to get help from you and others like you, that will help without mashing on my tune or my setup.
I am not a tuner, never tuned at all till I built my motor. I was fully aware that it was a big cam to learn with. I also found out that Fast injectors, especially Fast injectors above the flow rate limit are a nightmare. And FlexFuel conversions for newbie on an E40 can be a bit frustrating.
My tune needs a lot of work and may never be " right " as some say but if I can get it to start good, run good, drive good, make good power and be safe then that is " right " for me.
I am posting tonight's tune and log. If someone can look them over and see anything else that would help.
Well good. Think about what the spark modifiers have done and then you can fine tune it further. Just be careful with the 'Alcohol' spark modifier on the top end at WOT. It's going to be 32 degrees advance if applied to the High Octane table. Might want to check over that.
Just fyi increasing the magnitude of over/underspeed idle spark can actually result in a more stable idle on a cammed engine. I see you did it some, but try more. Unstable idle is hard on things. Imagine your poor timing chain and tensioner. Yeah a cam chops, but this is excessive. Upping the idle to 850 will help stabilize things, too.
My 97 L31 based 383 has been sitting for a couple of weeks. Still had summer blend E85 in it reading about 82% Ethanol. At 29F on the coolant temp it took a little more cranking then normal, but still fired up on the first crank and ran. Idled a bit rough until it got a little heat into it. While I was in town, I put about 10 gallons of 93 octane E10 into it to dilute the ethanol a bit. Right after cold start the PCM was commanding 40* BTDC of timing with the wideband showing about 0.70 Lambda at about 950 rpm. Cranking air/fuel ratio was about 4:1 and decayed down to 7.5:1 pretty quickly. By 130F on the coolant it was commanding 9.73:1. The PCM coolant adder adds a good bit of spark timing at lower loads until the engine temps climb a bit. One thing I did years ago is zero out the catalyst warmup spark retard as even in stock form it made the accelerator feel dead when the engine was cold because of how much timing it pulled.
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