Why soo much black soot coming out of exhaust???

fmoua916 · 04-27-2016, 10:59 PM

Didnt really notice any black soot coming out of the mufflers when car was all stock but now that i installed ar design dp and pe mod muffler and tuned on cobb stage 2+fmic im getting a bunch of soot from the muffler. Had a cylinder 1 misfire after cobb tune and dp install so installed new delphi coils, nkg plugs and walnut blast so misfire went away. Not sure what it causing soo much black soot to shoot out im guessing maybe a bad injector or something that may be starting to go bad. Here is a pic of how much soots it have starting the car up for about 10 mins and revving it a couple times.

Wilt · 04-28-2016, 12:44 AM

Black soot generally indicates too rich of a mixture being combusted.

In the days before emissions control, whitish = lean, light gray = just right.

thomas88162 · 04-28-2016, 01:45 AM

That would appear.... excessive. You probably have a sticky injector leaking fuel after shutoff.

Cory S · 04-28-2016, 06:58 AM

Cobb maps command way too rich AFR's. I was consistently seeing 11.3:1, with drops as deep as 10.7:1.

I've done much modifying to the mapping values. I target 13.4:1 @ 2500rpm, down 12.2:1 by 4100rpm and up.

robthewrench · 04-28-2016, 07:15 AM

It's too much fuel. Any custom tune makes more power by consuming more fuel and generally running richer than needed in order to make this power. Cobb makes no promises about emissions, only power.

If you think the wall is dirty with carbon, pull your plugs. One or more will be really dirty.

mxchris727 · 04-28-2016, 08:39 AM

I would change you oil often if that's how those tunes normally run. I'm completely stock with no soot at all.

fmoua916 · 04-28-2016, 12:59 PM

Quote:

Originally Posted by robthewrench

It's too much fuel. Any custom tune makes more power by consuming more fuel and generally running richer than needed in order to make this power. Cobb makes no promises about emissions, only power.

If you think the wall is dirty with carbon, pull your plugs. One or more will be really dirty.

Yeah one of the plug on cylinder 1 was dirty when plugs were replaced.

xcusem3 · 04-29-2016, 08:02 AM

Mine does the same thing, leaky injectors are your culprit and no it will never completely go away even with a new set.

hassmaschine · 04-29-2016, 08:05 AM

maybe consider opening your garage door before starting the car. CO poisoning isn't a good thing.

fmoua916 · 04-29-2016, 07:21 PM

Quote:

Originally Posted by hassmaschine

maybe consider opening your garage door before starting the car. CO poisoning isn't a good thing.

I do open it but i did this just to see the soot

Nick4724 · 02-25-2020, 10:28 AM

Quote:

Originally Posted by fmoua916

Quote:

Originally Posted by hassmaschine

maybe consider opening your garage door before starting the car. CO poisoning isn't a good thing.

I do open it but i did this just to see the soot

Did you sort the issue?

04-27-2016, 10:59 PM	#1
fmoua916 First Lieutenant 72 Rep 385 Posts Drives: 335i Join Date: Sep 2015 Location: sacramento iTrader: (1)	Why soo much black soot coming out of exhaust??? Didnt really notice any black soot coming out of the mufflers when car was all stock but now that i installed ar design dp and pe mod muffler and tuned on cobb stage 2+fmic im getting a bunch of soot from the muffler. Had a cylinder 1 misfire after cobb tune and dp install so installed new delphi coils, nkg plugs and walnut blast so misfire went away. Not sure what it causing soo much black soot to shoot out im guessing maybe a bad injector or something that may be starting to go bad. Here is a pic of how much soots it have starting the car up for about 10 mins and revving it a couple times.
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04-28-2016, 12:44 AM	#2
Wilt Major 228 Rep 1,041 Posts Drives: 2011 328i Join Date: Mar 2015 Location: SF Bay area iTrader: (0)	Black soot generally indicates too rich of a mixture being combusted. In the days before emissions control, whitish = lean, light gray = just right.
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04-28-2016, 01:45 AM	#3
thomas88162 Lieutenant 19 Rep 595 Posts Drives: E92 328i Join Date: Jun 2013 Location: Clinton, IN iTrader: (0)	That would appear.... excessive. You probably have a sticky injector leaking fuel after shutoff.
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04-28-2016, 06:58 AM	#4
Cory S Major 305 Rep 1,163 Posts Drives: 2011 335i-X Join Date: Oct 2015 Location: N.H. iTrader: (0)	Cobb maps command way too rich AFR's. I was consistently seeing 11.3:1, with drops as deep as 10.7:1. I've done much modifying to the mapping values. I target 13.4:1 @ 2500rpm, down 12.2:1 by 4100rpm and up.
	Appreciate 0 Quote

04-28-2016, 07:15 AM	#5
robthewrench Captain 266 Rep 952 Posts Drives: 11 E90 335i Join Date: Aug 2014 Location: Columbus OH iTrader: (0)	It's too much fuel. Any custom tune makes more power by consuming more fuel and generally running richer than needed in order to make this power. Cobb makes no promises about emissions, only power. If you think the wall is dirty with carbon, pull your plugs. One or more will be really dirty. __________________ bone stock
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04-28-2016, 08:39 AM	#6
mxchris727 Captain 193 Rep 666 Posts Drives: '03 M5, '06 325i, '12 M3 Join Date: Aug 2012 Location: Westport, CT iTrader: (0)	I would change you oil often if that's how those tunes normally run. I'm completely stock with no soot at all. __________________ BMW GT1 (INPA, DIS, WinKFP, ect..), ISTA/P & /D is up and running! PM me if you want to stop by and code your car.
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04-29-2016, 08:02 AM	#8
xcusem3 Lieutenant 457 Rep 539 Posts Drives: 2013 M3 Join Date: Jan 2015 Location: Calgary iTrader: (0)	Mine does the same thing, leaky injectors are your culprit and no it will never completely go away even with a new set. __________________ CP-E DP's / Remus Race / ETS 7" FMIC / AFE DCI / Cobb V3 / ETS CP / HKS BOV
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04-29-2016, 08:05 AM	#9
hassmaschine Major General 3966 Rep 7,215 Posts Drives: "NBO" 330i Join Date: Jun 2014 Location: earth iTrader: (0)	maybe consider opening your garage door before starting the car. CO poisoning isn't a good thing.
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