Impreza trouble starting

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

Re: Impreza trouble starting

Post by Slowie »

I notice in the logs that as soon as the log starts, the runmode is already in "run", not "crank", indicating that the cranking enrichment is not being applied.

I am not sure why this would be though, as according to the map you uploaded earlier, the engine is defined to be cranking if rpm exceeds 100, and should only be considered to be "running" when rpm exceeds 600. But the logs indicate something else going on. Will scratch around a bit more.

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

Re: Impreza trouble starting

Post by stevieturbo »

and for trying to tune any starting.

Although there's maybe a little paradox in there....get it starting properly when warm first, before worrying too much about cold.

When warm it should need very little additional fuel during starting.

Often people just throw tons of fuel at a poor starter....which ends up being an additional cause of poor starting.

Always start with little fuel, and work up. ( and ensure engine has sufficient air to start )

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

Re: Impreza trouble starting

Post by davidmcluckie »

How do I find out if there is enough air to start?

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

Re: Impreza trouble starting

Post by stevieturbo »

davidmcluckie wrote:How do I find out if there is enough air to start?
Well its almost easier than fuel. If it doesn't have enough air it will never start.

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

Re: Impreza trouble starting

Post by davidmcluckie »

stevieturbo wrote:
davidmcluckie wrote:How do I find out if there is enough air to start?
Well its almost easier than fuel. If it doesn't have enough air it will never start.
Can't argue with that. :)

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

Re: Impreza trouble starting

Post by Slowie »

With the laptop connected to the car, could you verify the following settings please:

Under Breakpoints and Thresholds -> Engine Mode Thresholds, check the following:

Cranking Mode Engine Speed Threshold should be 100
Cranking Mode Threshold Hysteresis should be 50
Run Mode Engine Speed Threshold should be 600
Run Mode Threshold Hysteresis should be 200

The numbers were like that in the map you uploaded, just want to verify that the ECU has the same values programmed in.

Your firmware on the ECU is 7 years old, it might be worthwhile to update it to the latest one. We can assist you with doing this, and maybe some of the bugfixes along the way help out with this issue.

Another way to test if you need more air during cranking is to just crack open the throttle a bit. If it fires up easier, we know you need more cranking airflow.

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

Re: Impreza trouble starting

Post by davidmcluckie »

Can confirm. 100, 50, 600, 200.

Firmware update. Sounds dangerous. I'm in.

Assistance in updating would be greatly appreciated.

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

Re: Impreza trouble starting

Post by Slowie »

You can watch this help video, which begins with some info on how to update the firmware and maps. I suggest first saving a fresh copy of the map in SCal, as well as in SCfg (in SCfg, go Device -> Get Config, then File -> Save).

Then you can run the .exe file for the latest firmware (found in the sticky thread in the S6 forum), and then update your saved maps and import them into the ECU.

If you like, I'm sure someone here can help you update your SCal and SCfg maps to the latest version, then you simply have to flash the ECU and import the updated maps.


Have you tried giving a bit more throttle when cranking? Does that make startup better or worse?

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

Re: Impreza trouble starting

Post by davidmcluckie »

I would happily pay someone to update the Cal and config to work with the latest firmware.

This also explains why the aircon hasn't got a belt on. Not for more power, but at the time the Syvecs ecu couldn't control it. But that's on a to do list.

Any takers on updating my Cal and config to the latest firmware, then I can go ecu flashing?





Haven't tried a part throttle start yet.

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

Re: Impreza trouble starting

Post by Slowie »

Lol, I'll update it for free.

I assume you are still using the cal from your first post. I have updated it to 1.79.2 fw, and filled in sensible values where new maps exist (e.g. you can now ignition coil dwell increase/decrease with boost). The only two items that are left with questions marks in the map are ones I am unsure of:

I am not sure how your antilag switch is configured. Assuming it simply connects to ground, the settings highlighted are correct, otherwise they need to be changed. I am sure they are correct as is, though.

Same with the Variable Vale Timing -> Control Valves setup. I have the default values, which should be correct. If the car drives differently, we may need to change those.

Before flashing the firmware please send the config from SCfg, like I described earlier. This also needs to be updated, otherwise your logging config will be lost.

After we have done that, you can flash the ECU.

That was a lot of work! A ton of items have changed over the years!
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Subaru impreza BW05 HGF engine change trim 1.79.2.SC
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