Brz doesn't like to idle

[toughguy39]

Hi guys,
Recently went in for maintenance, swear this is like the third post I've made in a month. What happens is after I drive off after I've given it time to warm up, when coming to a stop and putting the car to neutral the car dies. It doesn't happen every time maybe 40% of the time. There are some drives it doesn't even come close to stalling. The problem seems to happen when A: it's hot outside(90F) and/or B: I don't idle for like 10 minutes. Currently in the tuning process, I'm on the second tune from my tuner. I've emailed him and am waiting for a response. I also seem to be running a little lean (14.7-15.3 AFR) at idle. Fuel pressure being reported by the flex fuel kit is at 55PSI and I'm running 93 octane. Other than this problem she runs great.
Mod list(changed from since working):
Dw300c and id1050x injectors
Flex fuel kit
Boost controller
EVAP disconnected, hoses clamped
Spark plugs
Belt replacement
New intake filter
Cam plate replaced
2017 intake manifold

Any suggestions are greatly appreciated!

[Spawn_Of_Creation]

Do you have a custom tune? If so, I would have the tuner take a look at it. There are multiple things there in your list that change dynamics.

[Bonburner]

FA20 is pretty notorious for poor idling.

But since you've reached out to your tuner, you're in the right direction.

Personally I found slightly improved idling after I swapped out my dying battery, ignition coils, and spark plugs and Chevron/Shell gas.

After some hard long use, it can still have a bit of a rougher idle still but better than before.

[tomm.brz]

Let me guess.
Ecutek racerom and US base tune, like it ends with the letter C...




Bug. I talked about it often, no one ever cared about it, so there is no fix for you unless you force your tuner to convert your tune with an EU base tune... thing that he will not do it also because he's not aware of, and your idle will always suck

[tomm.brz]

Originally Posted by Bonburner

FA20 is pretty notorious for poor idling.

But since you've reached out to your tuner, you're in the right direction.

Personally I found slightly improved idling after I swapped out my dying battery, ignition coils, and spark plugs and Chevron/Shell gas.

After some hard long use, it can still have a bit of a rougher idle still but better than before.

not really. once it settles and only DI is used for idle, is pretty rock solid


Who has idle problems, has actually tune problem

[Bonburner]

Originally Posted by tomm.brz

not really. once it settles and only DI is used for idle, is pretty rock solid


Who has idle problems, has actually tune problem

No, its notorious. You can google it yourself, but here's an example of just how common it was (large car publications were publishing articles about it).

https://www.motortrend.com/news/we-h...g%20conditions.

https://www.autoweek.com/news/a19712...ay-fault-lies/

https://www.autoblog.com/2012/10/05/...e-ecu-reflash/

https://www.cars.com/articles/2015-2...1420683185723/

1200 hits:
https://www.google.com/search?q=frs+...=2560&bih=1307

[tomm.brz]

it s notorius but i ve retune 70 cars since 2018 and no one has idling problem.. it s fixab le, just that most people can t find the right solution

stock tunes and ots tunes Have idling problems btw. So do every custom tune that has idle set like them.

[makinen]

Do flash new tune when the engine is warm. And search "subaru idle relearn".

[tomm.brz]

Originally Posted by makinen

Do flash new tune when the engine is warm. And search "subaru idle relearn".

You probably have an Asian base tune as your custom tune, with no bugs

Those guys have US base tunes that have a bug with ecutek racerom that will force them to use PI during idle.. they ll never get a steady idle no matter how they help with the relearn, specially with big injextors

[Tcoat]

Originally Posted by Bonburner

No, its notorious. You can google it yourself, but here's an example of just how common it was (large car publications were publishing articles about it).

https://www.motortrend.com/news/we-h...g%20conditions.

https://www.autoweek.com/news/a19712...ay-fault-lies/

https://www.autoblog.com/2012/10/05/...e-ecu-reflash/

https://www.cars.com/articles/2015-2...1420683185723/

1200 hits:
https://www.google.com/search?q=frs+...=2560&bih=1307

OK so your first 3 links are from October 2012 so not sure how many people actually had an issue. They all are just clickbait's parroting each other anyway not even independent investigations. The issue was fixed before 99% of the cars wee ever sold.
Your 4th link is an issue very specific to one model year with AT only. Again it was fixed with a simple update.
Your 1200 other hits mostly start with "I have an XXX turbo or tune and have idle issues". Pretty much supports they are a mod and tune related problem. Oh and of course there are the many many "Happens when the A/C is on" which is perfectly normal but some people refuse to understand that.

Idle issues are not common on unmodded cars after the very first batch. If somebody with a tuned car has this issue they need to check the tune not ignore it and say "OH these engines all do that". They don't.

[Lantanafrs2]

The only time my idle gets weird is when the ac is turned on/off

[Ultramaroon]

I have never had an idle issue with my bone stock '13. It still has the second ROM, the one where they removed the DI seal-blowing feature.

[spike021]

Originally Posted by Tcoat

Idle issues are not common on unmodded cars after the very first batch. If somebody with a tuned car has this issue they need to check the tune not ignore it and say "OH these engines all do that". They don't.

This pretty much, speaking from experience...

[tomm.brz]

Originally Posted by Lantanafrs2

The only time my idle gets weird is when the ac is turned on/off

while it is perfectly normal, there is still a way to tune this out and minimize it