Cold start EJ207

[dx4picco]

 

Hello guys,

I would like to peak your mind on what I could potentially improve for the cold start to be more reliable.

As you can see during the log, under 10°C cold start starts to be miss then run, up to 3-4 miss then run.

today it was two miss

log: https://drive.google.com/file/d/1RnpSC8q5dWvVPJX2XaNd9Lz1TawckfiM/view?usp=sharing

map: https://drive.google.com/file/d/1aE-3pE4kjAQAUoziV54-SYHiGGdnZTOb/view?usp=sharing

 

I can see the ethanol content "bug" that was reported by someone else but it is not affecting my case.

it seems like more pre crank prime doesn't help, maybe it tends to wet the plug?

The log you can see is about the best I can do.

Injectors are ID1050X2. engine is JDM EJ207 stock engine with my06 DBW.

What do you guys think? what else should I try? even more cranking enrichment?

thanks for your input

 

 

[Adamw]

Turn off wall wetting compensation for now to see if that improves it.  There is a recently discovered bug where the wall wetting compensation would sometimes hold the injectors open longer than they should be on the first crank after a power cycle.  This has been fixed in the next release but is still in testing.

[dx4picco]

Hello Adam,

it doesn't seem to have make a difference to me?

here is a log with 0% instead of 70% WW.

https://drive.google.com/file/d/1mLCZRb6EkW5DpT0vPD90rkN3pkt8oNUH/view?usp=sharing

maybe it has but temp is a bit different from yesturday. so still 3 attemps

 

And merry Christmas 

[Adamw]

Sorry I didnt realise you were flex fuel.  Cold start at 10°C with a high ethanol content is never going to be great, especially with large injectors.  

Due to ethanol's low vapor pressure, when everything is cold including the fuel, intake ports, injectors, rail etc, you will have very little vapor produced in the intake port.  You need vapor for combustion to occur, adding extra liquid fuel helps produce a little more vapor but you reach a point where there is so much liquid it starts to work against you.  If you are not seeing noticeable changes when adding or reducing crank enrichment then you are probably sitting somewhere around that point now. 

Two things that may help to produce more vapor; retard injector timing so that fuel is injected when port velocity is highest, try around 180-220BTDC EOI.  Add more start-up offset to increase cranking airflow.  Reduce start-up hold and decay to prevent a big flare when it catches.  

 

[dx4picco]

Hey Adam, 

It is indeed. Around 65-70 E these days. 

That is also the case regarding more or less fuel. It seems more pre crank has negative effects. 

Less cranking is a bit worse and I am a bit reluctant to put even more than what currently is for cranking enrichment. 

I will try that injection angle tip. 

"Funily" Enough my gc8 with 850cc injector starts up extremely well in comparison to that 2006 jdm engine. 

Even on ethanol. Would it be only injector spray/atomising related? 

I didn't think and I hoped these id1050s were not so big so that I wouldn't get these issues 

[dx4picco]

Tried, it. I don't think it was going the right way.

https://drive.google.com/file/d/1bJac7hmC33TdKG19hzyOSFYzYOs8orQs/view?usp=sharing

after 4 unsuccessfull starts at 200°, I switched it back to 400 like it was and it stayed on.

then after the start I tried changing injection angle, 180 and 200° were leaning things out about a point, and 220° maybe one or two tenth.

I take it that this engine prefers 400° en injection point?