Roughness after cold start

rjd_F30 · 07-28-2018, 03:34 PM

Title pretty much says it all. Looking to get some opinions on a roughness I'm having, only at idle, after cold starts. The car will start and idle fine for about 2 seconds, and then it sort of shudders and just overall idles roughly (but never close to stalling), and at that point I put it in drive to get rid of it. As soon as I put it in drive or give it any gas, the roughness goes right away. Idle after start (red lights, stop signs etc.) is absolutely smooth. This has only started happening after I got rid of the cold start cycle after my catless DP install via BM3. When I was catless but still had cold start enabled it was fine. I tried new spark plugs, and that didn't fix the issue. Any thoughts, comments? I'm thinking (hoping) it's a tuning issue, because the issue is directly correlated to my turning off the cold start cycle via BM3. I got one fault code about a week ago for super knocking in cylinder 4 and injection shutdown after the car stuttered under WOT. Cleared the code and it never came back. Mods are in signature. Thanks!

P.S. I noticed that the roughness was worse after clearing adaptations in the DME, perhaps the DME has to adapt to not having a cold start cycle? Just a thought.

nemobanks · 07-28-2018, 06:47 PM

Probably a vacuum leak

TylerMcCraw · 07-28-2018, 07:16 PM

If you want to disable the cold start, and not have the rough idle, do a custom cold start RPM via bootmod3 and set it too 1k rpm.. I gad the same issue and this soved it.

rjd_F30 · 07-28-2018, 07:53 PM

Quote:

Originally Posted by TylerMcCraw

If you want to disable the cold start, and not have the rough idle, do a custom cold start RPM via bootmod3 and set it too 1k rpm.. I gad the same issue and this soved it.

Oh ok thanks for the input I'll try that ASAP. So to be clear, set "Cold Start (cat heating)" to off and then Cold Start RPM to 1k?

rjd_F30 · 07-28-2018, 07:55 PM

Quote:

Originally Posted by nemobanks

Probably a vacuum leak

I would've thought something similar but it only happens when I disable cold start w/ BM3, I feel like if it were a vacuum leak it would still happen regardless of the cold start setting.

Noelified · 07-28-2018, 10:24 PM

Did you also code flaps always open...shouldn't matter but who knows.

rjd_F30 · 07-29-2018, 04:15 AM

Quote:

Originally Posted by Noelified

Did you also code flaps always open...shouldn't matter but who knows.

I did, not sure that would have a hand in this issue though...

TylerMcCraw · 07-30-2018, 09:10 AM

Quote:

Originally Posted by rjdnyy224

Oh ok thanks for the input I'll try that ASAP. So to be clear, set "Cold Start (cat heating)" to off and then Cold Start RPM to 1k?

Yes, Exactly.

BunkerJ · 07-30-2018, 09:31 AM

Same as others, try turning it off. I turn mine off personally and still just let it idle for a minute in the morning. Cold start is put there for cat heating.

rjd_F30 · 07-30-2018, 02:21 PM

Quote:

Originally Posted by BunkerJ

Same as others, try turning it off. I turn mine off personally and still just let it idle for a minute in the morning. Cold start is put there for cat heating.

You mean turning off the Cold Start delete, i.e. staying OEM cold start? I already have the cold start cycle set to off but that's when I get the roughness.

BunkerJ · 07-30-2018, 02:55 PM

Quote:

Originally Posted by rjdnyy224

You mean turning off the Cold Start delete, i.e. staying OEM cold start? I already have the cold start cycle set to off but that's when I get the roughness.

Ah, interesting. Yeah, I guess try OEM then? Could also submit a ticket to see if there is something wrong with that setting for your DME.

rjd_F30 · 07-30-2018, 03:29 PM

Quote:

Originally Posted by BunkerJ

Ah, interesting. Yeah, I guess try OEM then? Could also submit a ticket to see if there is something wrong with that setting for your DME.

I guess I could try OEM and tone the cold start down to 1k rpm. When I had the DP without getting rid of cold start it was terribly loud and not very pleasant sounding. I'll play around with the settings and see if I can't get it fixed myself. If not, I'll submit a ticket.

BunkerJ · 07-31-2018, 09:09 AM

Quote:

Originally Posted by rjdnyy224

I guess I could try OEM and tone the cold start down to 1k rpm. When I had the DP without getting rid of cold start it was terribly loud and not very pleasant sounding. I'll play around with the settings and see if I can't get it fixed myself. If not, I'll submit a ticket.

Trust me, I get that haha. Before we had the config and my cold start was still enabled, I felt terrible not only for my car (Because I had to shift her into drive immediately upon start to kill the cold start) but for my neighbors who had to hear it and/or have their car alarms go off. Lol.

rjd_F30 · 08-02-2018, 06:07 PM

Okay so I have a little update on the issue.

I opened a support ticket with PTF regarding not the rough idle issue, but the fact that my CEL for the DP was not going away even though I set it to (scanned for codes it was the DP causing the CEL). I talked with them about that and they effectively said that you're not supposed to run stage 1 with a catless downpipe like I was, it's just not meant for it, and that I should go up to stage 2. After hearing that, I was kind of hoping the same would be true for the rough idle issue. So, I flashed stage 2 with cat monitoring off, cold start off and idle rpm set to 1k. Flashed, started the car, and the rough idle is still there. Can't speak the CEL yet because I have only driven 10 or so miles since the Stage 2 flash. I logged and it looks fine with Stage 2 so we're good there. But anyway, while I had the support ticket open, I mentioned the rough idle issue to them and explained to them everything I explained on this thread. They advised that I set idle RPM to default (they recommended this after the stage 2 flash, that's why it was set to 1k in aforementioned flash), and I explained that I tried that and it didn't work. I also explained that even when set to 1k or OEM or whatever, the idle just drops to 600 immediately anyway, regardless of what I set it at, which is kind of... curious (thoughts on that would be appreciated). Anyway, that was my last contact with them, I'll update again once I hear back. Just wanted to give a little progress report.

P.S. In reading this post I see it is all over the place, hopefully you can sift through it and realize the important stuff

rjd_F30 · 08-03-2018, 09:55 AM

TylerMcCraw when you have the cold start turned off and rpm set to 1k, do the rpms rest at 1k when you start the car to resemble a cold start? Could you possibly take a video of your tachometer on cold start? Or anyone else who has cold start tuned out via BM3? Trying to understand what the cold start rpm does because it seems to do nothing for me. Thanks in advance

rjd_F30 · 08-11-2018, 09:39 AM

Another update: Turned Cold Start (Catheating) back on, and set idle rpm to 950. Good f--king god is it loud, but it idles perfectly! Looks like I have to choose between really loud but smooth start, or nice and quite but rough start

Beamerboy101400 · 02-24-2020, 12:37 AM

Quote:

Originally Posted by rjdnyy224

Another update: Turned Cold Start (Catheating) back on, and set idle rpm to 950. Good f--king god is it loud, but it idles perfectly! Looks like I have to choose between really loud but smooth start, or nice and quite but rough start

Really old thread but did you ever find a way to have the cold start off and have it not be rough?

rjd_F30 · 02-24-2020, 08:55 AM

Quote:

Originally Posted by Beamerboy101400

Really old thread but did you ever find a way to have the cold start off and have it not be rough?

Yah, I just kind of let it go and it settled over time. Leads me to believe it was an adaptations issue. I didn't really do anything to fix it, and it's fine now.

CandyRedRC46 · 02-24-2020, 10:58 AM

Why not set the cold to off and the cold idle a little higher? I would try 1500-2000, for more of a gts roar like start up. Its not the rpms of the cold start that make obnoxious sound, its the timing retard for the cat heating and also the wastegate opening as well. I really wish I could get in there and really adjust all the settings for a more ideal start up.

DMM2 · 07-09-2020, 09:23 AM

Quote:

Originally Posted by rjd_F30

Quote:

Originally Posted by Beamerboy101400

Really old thread but did you ever find a way to have the cold start off and have it not be rough?

Yah, I just kind of let it go and it settled over time. Leads me to believe it was an adaptations issue. I didn't really do anything to fix it, and it's fine now.

OP, I'm currently having the exact same issue you were having. I have 330i (B46), and the idle is super rough with the cold start deleted. I also have a catless DP, but the rough idle problem existed before that was installed (when cold start was deleted via BM3). I've been in contact with PTF, but they are insisting I need to change my spark plugs.

Approximately how long did it take before your rough idle settled out?

Cheers

rjd_F30 · 07-10-2020, 07:30 AM

Quote:

Originally Posted by DMM2

OP, I'm currently having the exact same issue you were having. I have 330i (B46), and the idle is super rough with the cold start deleted. I also have a catless DP, but the rough idle problem existed before that was installed (when cold start was deleted via BM3). I've been in contact with PTF, but they are insisting I need to change my spark plugs.

Approximately how long did it take before your rough idle settled out?

Cheers

I would say after about 100-200 miles everything was smooth, though it's really hard for me to give an exact number of miles or length of time. It was a while though, didn't happen after just a couple drives around the block.

floridaorange · 07-10-2020, 07:55 AM

So glad the rough idle days are behind me - every light it's just embarrassing.

07-28-2018, 03:34 PM	#1
rjd_F30 Brigadier General 2000 Rep 3,679 Posts Drives: 2013 335i 6MT Join Date: Jun 2017 Location: New Jersey iTrader: (0)	Roughness after cold start Title pretty much says it all. Looking to get some opinions on a roughness I'm having, only at idle, after cold starts. The car will start and idle fine for about 2 seconds, and then it sort of shudders and just overall idles roughly (but never close to stalling), and at that point I put it in drive to get rid of it. As soon as I put it in drive or give it any gas, the roughness goes right away. Idle after start (red lights, stop signs etc.) is absolutely smooth. This has only started happening after I got rid of the cold start cycle after my catless DP install via BM3. When I was catless but still had cold start enabled it was fine. I tried new spark plugs, and that didn't fix the issue. Any thoughts, comments? I'm thinking (hoping) it's a tuning issue, because the issue is directly correlated to my turning off the cold start cycle via BM3. I got one fault code about a week ago for super knocking in cylinder 4 and injection shutdown after the car stuttered under WOT. Cleared the code and it never came back. Mods are in signature. Thanks! P.S. I noticed that the roughness was worse after clearing adaptations in the DME, perhaps the DME has to adapt to not having a cold start cycle? Just a thought. __________________ Instagram: rjd_f30 \| Current: EBII 2013 335i 6MT RWD & Sprint Blue 2008 Audi RS4 \| Retired: 2013 328i, 2000 XTerra, 2022 Civic Si \|
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07-28-2018, 06:47 PM	#2
nemobanks Nemo banks 65 Rep 253 Posts Drives: 2014 BMW F30 328i Join Date: Oct 2016 Location: Miami Fl iTrader: (0)	Probably a vacuum leak __________________ FBO N20, G-Plus Oil Cooler , Injen Cold Air Intake, MST turbo inlet, AFE Charge Pipe, BMS Oil Catch Can, Forged Motorsport Blow of Vavle, Wanger FMIC, Circuit Werkes Catless Downpipe, Full Straight 3inch exhuast. Stage 2 Active Auto Werke.
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07-28-2018, 07:16 PM	#3
TylerMcCraw Second Lieutenant 154 Rep 232 Posts Drives: 2013 BMW F30 Join Date: Jan 2015 Location: Charlotte NC iTrader: (0)	If you want to disable the cold start, and not have the rough idle, do a custom cold start RPM via bootmod3 and set it too 1k rpm.. I gad the same issue and this soved it. __________________ 2013 Jet Black Sport Line 328i: H&R Springs, 12 & 18mm Spacers, 335i Exhaust conversion.
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07-28-2018, 10:24 PM	#6
Noelified First Lieutenant 228 Rep 325 Posts Drives: 2016 F36 Join Date: Mar 2017 Location: CT iTrader: (0) Garage List 2016 BMW 428ix F36 GC [0.00]	Did you also code flaps always open...shouldn't matter but who knows.
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07-30-2018, 09:31 AM	#9
BunkerJ Colonel 1032 Rep 2,382 Posts Drives: 2013 328i Join Date: Mar 2017 Location: San Diego, CA iTrader: (0)	Same as others, try turning it off. I turn mine off personally and still just let it idle for a minute in the morning. Cold start is put there for cat heating. __________________ 2013 F30 328i: MHI Big Turbo, GFB DV+, Mishimoto CAI, ER TIC/CP/Catless DP, AWE Touring Quad Exhaust w/ Resonated Midpipe, NGK LI Plugs, BM3 with PTF Stage 2 91 AGG Tune, Fuel-it Stage 2 LPFP, Solowerks S1 Coilovers, and DEPO/M-Sport Retrofit
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08-02-2018, 06:07 PM	#14
rjd_F30 Brigadier General 2000 Rep 3,679 Posts Drives: 2013 335i 6MT Join Date: Jun 2017 Location: New Jersey iTrader: (0)	UPDATE Okay so I have a little update on the issue. I opened a support ticket with PTF regarding not the rough idle issue, but the fact that my CEL for the DP was not going away even though I set it to (scanned for codes it was the DP causing the CEL). I talked with them about that and they effectively said that you're not supposed to run stage 1 with a catless downpipe like I was, it's just not meant for it, and that I should go up to stage 2. After hearing that, I was kind of hoping the same would be true for the rough idle issue. So, I flashed stage 2 with cat monitoring off, cold start off and idle rpm set to 1k. Flashed, started the car, and the rough idle is still there. Can't speak the CEL yet because I have only driven 10 or so miles since the Stage 2 flash. I logged and it looks fine with Stage 2 so we're good there. But anyway, while I had the support ticket open, I mentioned the rough idle issue to them and explained to them everything I explained on this thread. They advised that I set idle RPM to default (they recommended this after the stage 2 flash, that's why it was set to 1k in aforementioned flash), and I explained that I tried that and it didn't work. I also explained that even when set to 1k or OEM or whatever, the idle just drops to 600 immediately anyway, regardless of what I set it at, which is kind of... curious (thoughts on that would be appreciated). Anyway, that was my last contact with them, I'll update again once I hear back. Just wanted to give a little progress report. P.S. In reading this post I see it is all over the place, hopefully you can sift through it and realize the important stuff __________________ Instagram: rjd_f30 \| Current: EBII 2013 335i 6MT RWD & Sprint Blue 2008 Audi RS4 \| Retired: 2013 328i, 2000 XTerra, 2022 Civic Si \|
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08-03-2018, 09:55 AM	#15
rjd_F30 Brigadier General 2000 Rep 3,679 Posts Drives: 2013 335i 6MT Join Date: Jun 2017 Location: New Jersey iTrader: (0)	TylerMcCraw when you have the cold start turned off and rpm set to 1k, do the rpms rest at 1k when you start the car to resemble a cold start? Could you possibly take a video of your tachometer on cold start? Or anyone else who has cold start tuned out via BM3? Trying to understand what the cold start rpm does because it seems to do nothing for me. Thanks in advance __________________ Instagram: rjd_f30 \| Current: EBII 2013 335i 6MT RWD & Sprint Blue 2008 Audi RS4 \| Retired: 2013 328i, 2000 XTerra, 2022 Civic Si \|
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08-11-2018, 09:39 AM	#16
rjd_F30 Brigadier General 2000 Rep 3,679 Posts Drives: 2013 335i 6MT Join Date: Jun 2017 Location: New Jersey iTrader: (0)	Another update: Turned Cold Start (Catheating) back on, and set idle rpm to 950. Good f--king god is it loud, but it idles perfectly! Looks like I have to choose between really loud but smooth start, or nice and quite but rough start __________________ Instagram: rjd_f30 \| Current: EBII 2013 335i 6MT RWD & Sprint Blue 2008 Audi RS4 \| Retired: 2013 328i, 2000 XTerra, 2022 Civic Si \|
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02-24-2020, 10:58 AM	#19
CandyRedRC46 Lieutenant 242 Rep 420 Posts Drives: 2013 328i Join Date: Feb 2018 Location: Florida iTrader: (0)	Why not set the cold to off and the cold idle a little higher? I would try 1500-2000, for more of a gts roar like start up. Its not the rpms of the cold start that make obnoxious sound, its the timing retard for the cat heating and also the wastegate opening as well. I really wish I could get in there and really adjust all the settings for a more ideal start up.
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