Cold starting E85 in cold temps

I figured I'd be starting a thread sooner or later to discuss how to handle cold starting engines running E85 in cold temps. Different strategies can be employed, including mixing a gallon or two of straight gas, altering cold-start fueling tables, etc.

My fuel trims tell me I am still running summer blend E85 (min 79% alcohol), so these thresholds might change for the better. Anyhow, here's my experience so far:

~45 degrees seems to be threshold where I can detect starting takes an extra crank. No big deal at all and wouldn't be noticeable if I werent looking for it.

~32 degrees it definitely takes a few cranks, but not many. I've tried counting the cranks and it's around 6-7 here, but still only takes 1.5s or so to start.

~24 degrees. Well, this is the coldest I've started it. I was parked overnight in the mountains Weds night and was interested to see how the start would go in the a.m. Just fine! Maybe 7-8 cranks and still started in 2.0s or less.

Anybody have any different experience or is my experience on par with yours? I was anticipating further tweaking of my winter tune to deal with cold starts, but it might not be much of an issue at all. When/if I make changes, I'll post back here.

Good info.

Frankly, I'm surprised it works that well.

mine takes just a tic less cranking that yours, but once it fires up, it's no different than gas

I had been really pleased with cold starting E85 in cold temps.... until tonight.

I went out after work tonight after my car had sat for 9 hours and arctic cold set in. The temp was 1 degree F. The most cranking I had ever done was ~10 cranks or so and the coldest temp I had ever started was around 15-20F.

I cranked for 10+ seconds and it didn't come close to starting. I waited about 10 seconds again and still nothing close to starting at all. I did this for 5 minutes, repeating cycles of 10-12 seconds of cranking followed by a 20 second break. I kept the breaks pretty short because I was attempting to build any heat I could. The battery grew weaker and the engine would occasionally hiccup/stumble. The battery light on the dash came on as I just had a little amperage left. I tried a couple more times and thank goodness the engine finally came to life and I gave it a touch of gas. It was about 8-10 minutes of attemting to start before it finally caught, and then it didn't want to idle. I had to hold the throttle and the lowest smooth rpms I could, which were around 2300rpms.

Bottom line: Don't try to cold start pure E85 at zero degrees!! I immediately went to a gas station and added 2.5 gallons of 91oct to my nearly full tank of E85. I'm virtually certain that I have the FT headroom to accommodate it.

There is a dramatic change in start-ability somewhere between 0F and 15F.

I wonder how the GM flex fuel vehicles handle starting w/ E85 at low temps?

legend, the poor idle may have been from killing the battery

I was wondering how e85 would do in the blistering cold. I had to take a pic of my temp gauge this morning, it was really cold. Wiener, how is the temp in boulder?

I can't read your temp gauge... and I didn't know they put them down there (where my ashtray/lighter is). My temp gauge read -6F this a.m. I hope my starting goes smoother this afternoon... should be a little warmer and with some straight gas I thinnk I'll be okay.

mwiener... interesting about the dead battery causing idle problems - thanks.

Originally Posted by Legend

I can't read your temp gauge... and I didn't know they put them down there (where my ashtray/lighter is). My temp gauge read -6F this a.m. I hope my starting goes smoother this afternoon... should be a little warmer and with some straight gas I thinnk I'll be okay.

mwiener... interesting about the dead battery causing idle problems - thanks.

It says 1 degree, I took the pic with my cell phone. I moved my trip computer down with the AVO relocation kit when I cut out my cubby hole for my tv and deck. Back when I put in my in deck and tv there was no other option to get one in and I'm a car audio junky at heart and just couldn't stick with the stock HU. How old is your battery Legend?

time for a $40 block heater?

http://www.brandsport.com/sub-a0910a...ru-legacy.html

Originally Posted by 05pearl

time for a $40 block heater?

http://www.brandsport.com/sub-a0910a...ru-legacy.html

It would help for startups in the morning at the garage where there is access to an electric plug for the block heater. After the car has sat in a parking lot at work for 9 hours while the temp is frigid like today it won't do him much good without having a plug to hook the block heater up to.

-5 degrees Set a record cold in Denver today. Brrrrrrrrrr. I'm happy to report that I had much better luck today starting at -5F versus yesterday starting at 0F (see above). Adding 2.5 gallons to ~13 gallons of E85 makes a huge difference. The starter cranked about a dozen times and I thought I had it started but it stumbled for a second and died. I let the key go and turned again to start and it started right up.

Also, this time it idled perfectly right away which leads me to believe mwiener was right about it not wanting to idle last night because I killed the battery. I don't believe that was a tune issue.

So... I don't think any tuning is necessary for cold starting with E85, other than ensuring that lambda has a lean margin of error up top and that fueling is dialed in well enough so that the LTFT's can adjust for the addition of ~20% straight gas. I'll be checking my LTFT's in a few days. I can't drive WOT right now due to ice and can't drive fast enough to set up AFR D, so it's certainly safe for the kind of driving I am doing now, and more than likely ready for WOT on dry pavement in a day or two...

Wheww thats cold, last night was the coldest I have seen out here in a while (45 degees )

It was -13 when I left the other day. Even on 91oct I had to crank a few times and she made some noises while she fired up (Fuel Pressure regulator issue)

Update:

• With tanks of nearly pure E85 winter seasonal blend, AFR Learning D has been -2% to -5%. Cold starts are only good down to around 20 degrees. Colder than that and expect minutes of cranking and possibly not starting at all.
  
  With tanks of winter E85 augmened with straight gas (13 gallons gas, 2.5 gallons winter E85 - I call it "E58" since it's somewhere around 58% alcohol at this point), AFR Learning D has been -6% to -10%. Tested down to -6F and starts rather quickly, in around 2 seconds of cranking (maybe 10 cranks).

Conclusion: E85 can be run easily throughout the winter without map changes. The ecu has more than enough FT authority to deal with seasonal blends and augmentation with up to 2.5 gallons of straight gas. No knock increase observed in WOT logs despite lean E85 fueling and higher timing.

Note that I did richen my WOT targets to around 0.77 lambda or so instead of the 0.81 I run for my summer tune, so technically I did make a map change. I'm not sure if I would of had to, however, but did so this year as a precaution.