Ecotec cold starting issue on E85

[vp304]

Is no flex fuel support on my delco ecu so dont know if any help or not

[Dylan]

To the guys here that have gone from 98 to e85 is it only the first stage crank base that you have turned up to get the car to fire up from stone cold on e85?
Does the 2nd stage have to be turned up at all. I have done a heap of searching on here looking through posts etc. Have tried turning up the first stage crank table when under 40 deg c temp and playing with the minimum crank bpw value also. No matter what i try takes me minimum 15 sec or so for car to start from stone cold

I have found the second stage needs to be fairly accurate
I've changed to different injectors and even methanol fuels in the past. The first stage seems to be either very forgiving or maybe it's not active for long. But I'd say yes to adjusting second stage for sure.

[vp304]

Il double up the values for the cold temp areas on 2nd stage and see how i go thanks mate

[VX L67 Getrag]

Did you try holden202’s info to test asi think this forces stage 2 to know if it makes a difference.

[vp304]

I doubled up the 2nd stage and it fired in half the time this morning of 9 cranks or so (lot better than what it was past couple of days). Vx l67 getrag i saw holden202 mention something somewere about forcing it into stage 2 but do you have a link to post as hard to find of my phone. Not near my pc at moment thanks

[VX L67 Getrag]

Page1 of this thread!

[vp304]

Page1 of this thread!

Lmfaoooo ive lost da plot

[antus]

ethanol is about 2:1 by volume for the same burn, and you are talking ~ 85% that. Then at cold it burns less well and some of it does not combust. So for cranking maybe 2:1 is about right? I just made that up. But like others here say, the "Crank Fuel PW Vs Coolant" is probably the table to modify. I dont see a first and second stage like the older MAP ECMs. I'd multiply the stock cranking PW Vs Coolant table by values between about 1.6 and 2 and try that. If you have installed larger injectors, multiple by the size difference again to account for that too. For example if the injectors are twice as big, multiply the table by 2x. Then another say 1.8x for the different type of fuel, too. If you get lost put the stock table back in there and then apply your multipliers again.

[buzzard]

https://www.google.com/url?sa=t&rct=j&q ... i=89978449

From the link you can download a technical paper. Page 28 shows a table which gives the relative fraction of ethanol versus petrol vapour versus temperature. Below 20c the vapour content is predominately petrol. As antus pointed out, 85% of E85 is ethanol. Given that fuel in the liquid state will not burn, it is the vapour you are interested in. Whilst your PCM may not offer flex fuel support there is some very good guidance available in that Tahoe flex fuel calibration. I would suggest looking at the cranking AFR offset table in both cals.

[vp304]

Antus and Buzzard thanks for the info will look into it. Have got it firing up from stone cold after 6 to 7 cranks so getting a lot better