Rough cold start idle

E92Gok · 04-05-2020, 03:32 PM

Hey everyone, so I've been having this issue recently where my car had a rough idle on cold start. For a few seconds the needle jumps rpms from high to really low sometimes about to stall out. Only happens on cold starts after the car is warmed up it starts normally. My car is a 2008 e92 with 58xxx miles. Doesn't throw codes or anything. Possibly the idle control valve? Or maybe even the fuel breather valve? Anyone have a idea what it may be please drop a comment. Thanks!

NeverL8 · 04-05-2020, 09:51 PM

I had the same issue, changed spark plugs and battery and the problem went away so far (been 2 weeks)

Bpark1977 · 04-05-2020, 11:33 PM

Is your eco stock?

mapster37 · 04-06-2020, 05:30 AM

i had a similar issue. my was throwing a code for fuel pressure sensor. i replaced sensor-no more rough idle after cold start

E92Gok · 04-06-2020, 10:17 AM

Quote:

Originally Posted by TheRussski

I had the same issue, changed spark plugs and battery and the problem went away so far (been 2 weeks)

My battery and sparks were changed to long ago. Checked voltage on battery it was fine, so I doubt it will be that.

E92Gok · 04-06-2020, 10:18 AM

Quote:

Originally Posted by Bpark1977

Is your eco stock?

You mean my ECU? I am running a tune from BPM, with a primary decat

E92Gok · 04-06-2020, 10:20 AM

Quote:

Originally Posted by mapster37

i had a similar issue. my was throwing a code for fuel pressure sensor. i replaced sensor-no more rough idle after cold start

Hmm interesting, haven't gotten a code yet. Hopefully nothing serious

Bpark1977 · 04-06-2020, 10:57 AM

Quote:

Originally Posted by E92Gok

Quote:

Originally Posted by Bpark1977

Is your eco stock?

You mean my ECU? I am running a tune from BPM, with a primary decat

Lol. Autocorrect. Yes, your ECU.
I'd check and see if it's something they've had experience with.

E92Gok · 04-06-2020, 12:10 PM

Quote:

Originally Posted by Bpark1977

Quote:

Originally Posted by E92Gok

Quote:

Originally Posted by Bpark1977

Is your eco stock?

You mean my ECU? I am running a tune from BPM, with a primary decat

Lol. Autocorrect. Yes, your ECU.
I'd check and see if it's something they've had experience with.

Haha damn autocorrect. Gonna check my tune, that's a good point. Maybe if I return it too stock files see if the cold start improves that way.

NeverL8 · 04-06-2020, 03:48 PM

Could also be Fuel breather valve, does your idle bounces after fill up?

E92Gok · 04-07-2020, 08:44 AM

Quote:

Originally Posted by TheRussski

Could also be Fuel breather valve, does your idle bounces after fill up?

Nope nothing was happening after fill ups as well. I believe my tune is the issue. Went back to stock!

E92Gok · 04-07-2020, 08:48 AM

Update: I looked into my tune and went back to stock files yesterday. It had been sitting for a few hours so the engine was cold. Fired her up and it sounded great, no rpm bounce. Let her sit all night and started it up again this morning before work and no issues. I believe the tune was the issue. I will run it until I get my CEL (because I'm catless) back. And upload the tune again and see if that fixes it. Thank you all.

04-05-2020, 03:32 PM	#1
E92Gok Second Lieutenant 64 Rep 250 Posts Drives: 2008 e92 m3 Join Date: Dec 2015 Location: Los Angeles iTrader: (1)	Rough cold start idle Hey everyone, so I've been having this issue recently where my car had a rough idle on cold start. For a few seconds the needle jumps rpms from high to really low sometimes about to stall out. Only happens on cold starts after the car is warmed up it starts normally. My car is a 2008 e92 with 58xxx miles. Doesn't throw codes or anything. Possibly the idle control valve? Or maybe even the fuel breather valve? Anyone have a idea what it may be please drop a comment. Thanks!
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04-05-2020, 09:51 PM	#2
NeverL8 Captain 522 Rep 743 Posts Drives: Slow Join Date: Mar 2017 Location: SD iTrader: (0)	I had the same issue, changed spark plugs and battery and the problem went away so far (been 2 weeks)
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04-05-2020, 11:33 PM	#3
Bpark1977 First Lieutenant 183 Rep 305 Posts Drives: E93 M3 Join Date: Mar 2012 Location: Orange county, ca iTrader: (0)	Is your eco stock?
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04-06-2020, 05:30 AM	#4
mapster37 Captain 357 Rep 922 Posts Drives: F80 Join Date: Sep 2018 Location: Davie iTrader: (2)	i had a similar issue. my was throwing a code for fuel pressure sensor. i replaced sensor-no more rough idle after cold start
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04-06-2020, 03:48 PM	#10
NeverL8 Captain 522 Rep 743 Posts Drives: Slow Join Date: Mar 2017 Location: SD iTrader: (0)	Could also be Fuel breather valve, does your idle bounces after fill up?
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04-07-2020, 08:48 AM	#12
E92Gok Second Lieutenant 64 Rep 250 Posts Drives: 2008 e92 m3 Join Date: Dec 2015 Location: Los Angeles iTrader: (1)	Update: I looked into my tune and went back to stock files yesterday. It had been sitting for a few hours so the engine was cold. Fired her up and it sounded great, no rpm bounce. Let her sit all night and started it up again this morning before work and no issues. I believe the tune was the issue. I will run it until I get my CEL (because I'm catless) back. And upload the tune again and see if that fixes it. Thank you all.
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