|
Title: E85 Coldstart again! Post by: technic on September 13, 2014, 05:00:29 AM Hi,
Autumn/Winter is around the corner and I am converting a car with WB ME7 to E85 and coldstart - and it is not working well at all. Changed FKSTT, KFFWL and raised idle speed a bit at cold engine. I have also added one spark event for lower temps and elaborated with ignition at start, but no luck. Even start at +15 degrees works bad :( It runs just fine when warm. File attached if someone could have a look, please :) I'm even ready to pay for the solution if I have missed something vital :-\ Pm me in that case (just cold start, no tuning). /Lars (I have converted and tuned my old Audi A3 with M3.83 to E85 and coldstart is working fine at low temps, tested down to -18 degrees...Just don't see what I'm doing wrong) Title: Re: E85 Coldstart again! Post by: technic on September 14, 2014, 07:55:38 AM If I push the accelerator just very little, the car starts much better. Is there a map for torque request at cranking that I can use for this?
(or is it handled by throttle position directly?) In FR I have tried KFMDST, but it didnt do the trick :-\ Title: Re: E85 Coldstart again! Post by: Lost on September 14, 2014, 12:09:35 PM How does your FKSTT look like?
Take a screenshot. I got mine dialed in perfect, it maybe can help,you as well. Title: Re: E85 Coldstart again! Post by: technic on September 14, 2014, 12:22:18 PM Thanks, Pictures of FKSTT is attached :) I have tried more and less enrichment than shown in this map but no luck.
Edit: Attached picture of % enrichment also. Title: Re: E85 Coldstart again! Post by: Lost on September 15, 2014, 12:27:08 AM Way too low
Try 50 at 0deg 20 10 5 3 2 1.2 Title: Re: E85 Coldstart again! Post by: technic on September 15, 2014, 02:27:36 AM Ok, yes I have tried with much higher values (similar to yours), but didn't help. But I'll use your values to rule out FKSTT as the problem, thank you :)
I'll regap sparkplugs tonight also and see if it makes a difference. Title: Re: E85 Coldstart again! Post by: technic on September 16, 2014, 08:10:34 AM Wrapping up. Raised FKSTT even more - but the biggest impact was to change from BKR7E (which I normally use) to FR78. Maybe regapping the BKR would have worked also, I didn't try.
Let's see how it behaves in the winter when it's really cold. :) Title: Re: E85 Coldstart again! Post by: overspeed on September 16, 2014, 03:04:31 PM I live in Brazil, and I do many E100 convertions...
For etanol (E100) sometimes the spray patern make it would start even next 16~17°C (when Etanol don´t evaporate anymore), sometimes bad spray patern make hard to start even next to 20~22°C. With E85 is much more easy becasue you allways have some part of fuel becoming gas. There is something that helps in my case : increase KRKTE more than it would be (it will make moisture rich all time) and compensate it in all other maps like FKKVS, KFKFHM, TUVB (I´m not saying its the rigth solution, but helps a lot in these case) Title: Re: Re: E85 Coldstart again! Post by: technic on September 17, 2014, 11:31:03 AM Ok, I get the idea, but why TVUB?
Title: Re: E85 Coldstart again! Post by: overspeed on September 21, 2014, 01:32:30 PM with "wrong" KRKTE you´ll can get in some conditions that only tweaking TUVB and FKKS combined to make lambda =1' in LMM
Title: Re: E85 Coldstart again! Post by: technic on September 24, 2014, 07:44:19 AM Ok, cheers for the explanation.
I'm still having a hard time with this. Startup when cold works quite ok, and after ~30-60 seconds I can drive away. The problem is somewhere in between. If I touch the accelerator a few 0-15 of seconds after startup - the engine dies. If lucky, it doesn't die, but ends up with horrible idle.. I have changed the warmup maps, but I think the problem is during the transition from start-up to afterstart. Responsibility from this lies in FDEF, section ESNSWL. From what I understand FNSSM, KFWWNS and KFNSA could be my problem. Any thoughts? As it is quite hot right now, it's hard testing... Title: Re: E85 Coldstart again! Post by: technic on September 29, 2014, 04:55:12 AM Elaborated a bit with %STADAP also, but have not seen any significant improvement.
Now running a lot of enrichment on warm-up maps only. This will have do for now. Title: Re: E85 Coldstart again! Post by: Tony74100 on September 13, 2022, 05:34:05 AM Cold start maps are also designed to counteract the effect of wall wetting while intake and cylinders are cold. Ethanol behavious is not linear compared to gasoline. It s important to increase the cranking factor FKSTT but also the aftersart factor FNSSM for temperatures bellow 20c. We must not forget that we then need to evacuate this excess of fuel that has built up in the intake. That is why I also have increased the "decrease factor" fzanssm 1 and 2 in a "logical" amount compared to the increases applied to FKSTT and FNSSM.
Title: Re: E85 Coldstart again! Post by: thedrill on September 13, 2022, 06:21:28 AM Could you show your tables for fzanssm please.
Title: Re: E85 Coldstart again! Post by: Tony74100 on December 04, 2022, 10:09:44 AM You ll find my maps for afterstart with a multipoint injection 3.2BUB. I also increased by 30% throttle angle start from 30c to60c. Also increased fnssm load weighting by 20% from 25% load
All starts are perfect from 0c to 40c with e85 and my krkte and fkstt https://ibb.co/C2kxhyd https://ibb.co/9cztg2d https://ibb.co/3rFV5pW |