Impreza trouble starting

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davidmcluckie
Posts: 32
Joined: Mon Aug 14, 2017 8:27 pm

Impreza trouble starting

Post by davidmcluckie »

An absolute newcomer to the world of Syvecs here. But I'm willing and able to follow instructions.

I've got a fully forged 2005 STI Impreza which runs and idles nicely. It just doesn't like starting. Hot or cold.

I have read the Syvecs ECU likes to turn the engine over a few times before it starts but I think mine might be excessive.

I filmed me starting and have attached the Cal for you to look at. I've seen other posts about trigger values but I'm not exactly sure where to start.

Any help would be most appreciated.

Starting video - https://youtu.be/YCgewJUchvs
Attachments
Subaru impreza BW05 HGF Original.SC
(256.66 KiB) Downloaded 388 times

Slowie
Posts: 109
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie »

That definitely is not normal. It seems to be purely a mapping issue, just looking at the video. You are already running the Subaru G11 crank sensor setup, which has faster starting than the G10 type. Has the car been mapped? The starting settings seem very close to the Subaru base map values, and may need tweaking for your particular setup.

Can you take a datalog, from rest until started? Preferably start the log about 30 seconds before attempting to start, so the lambda sensor has time to warm up a bit.

Do you know how to take a synclog? That would also help.

davidmcluckie
Posts: 32
Joined: Mon Aug 14, 2017 8:27 pm

Re: Impreza trouble starting

Post by davidmcluckie »

Car is mapped and idles and runs fine.

I've seen the Synclog bit in Scal so I'll do that and report back.

Thank you.

stevieturbo
Posts: 956
Joined: Sun Dec 07, 2008 2:04 pm

Re: Impreza trouble starting

Post by stevieturbo »

As Slowie says, could just be some trigger thresholds.

Syncscope trace would help or even a quick glance to see how quick the ecu is going into 720sync.

But you do mention in the video it smells quite rich upon starting ? usually it would take a huge amount of extra fuel to prevent starting....or not enough air if idle bypass settings were maybe a little low.

Slowie
Posts: 109
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie »

Please also include the starting datalog, with warmed up wideband sensor (takes around 30s to warm up). That will help to diagnose starting fuel.

Forgot to ask, does it start like that with cold and hot engine, and also with cold and warm ambient conditions?

davidmcluckie
Posts: 32
Joined: Mon Aug 14, 2017 8:27 pm

Re: Impreza trouble starting

Post by davidmcluckie »

I got the cranking synclog. I think.

Starts the same with the engine hot or cold. Seemed to start better the other day when it was a little cooler outside.

Starting datalog? Where does that live?
Attachments
startcrank.txt
(220.71 KiB) Downloaded 352 times

stevieturbo
Posts: 956
Joined: Sun Dec 07, 2008 2:04 pm

Re: Impreza trouble starting

Post by stevieturbo »

I presume he means a datalog of it starting, as opposed to a "starting datalog" specifically....same end result though.

You'd need to configure logging to start at a suitable low rpm so it records as soon as you're cranking, and of course record/log relevant corrections etc.

The synclog does seem to get into 720 soon enough, but cranking does continue for some thereafter. So trigger levels etc are probably ok...at least they are not the cause of the slow starting.

So it probably is an air or fuel related issue. Whether too much or not enough idle air bypass, or too much or not enough fuel.

west_minist
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Location: Barbados
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Re: Impreza trouble starting

Post by west_minist »

Sounds more like cranking enrichment. Sounds like a lean start.

davidmcluckie
Posts: 32
Joined: Mon Aug 14, 2017 8:27 pm

Re: Impreza trouble starting

Post by davidmcluckie »

I'll apologise in advance. I've got logs, to me they look like squiggly lines. But hopefully they will be enlightening.

I got hold of another map from another Impreza and compared it's starting fuel to mine and it had more. So in the last two logs it should show that.

After I upped the starting fuel. It did seem to start and restart better when hot. But went back to it's normal long cranking after being left for wee while.

I really do appreciate any and all input from you guys.

The logs in a zip are bigger than the 1mb upload limit, so I put it on my Google drive.

https://drive.google.com/open?id=0B8FZe ... HA2WVJzY0E

west_minist
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Joined: Wed Nov 26, 2014 1:54 am
Location: Barbados
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Re: Impreza trouble starting

Post by west_minist »

Increase more fuel to colder ect.

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