Cobb Stage 2+ Question

135i · 10-11-2011, 11:57 PM

I keep getting misfires in cylinder 5 while driving at high boost.

I flashed back to Stage 1+ and for the most part the misfires stopped. Is there any qualitative way in knowing whether the injector v. the coil v. the spark plug is crapped out?

I bought a new spark plug to swap in as soon as I can find a fricking n54 spark plug tool. My gut says its the spark plug, but honestly I swapped them 6 months ago.

gracias!

themyst · 10-12-2011, 12:01 AM

Swap the plug first, if misfires persist, swap coil packs, if misfire moves with the coil pack, you found your problem. If misfire still persists in cylinder 5, possibly need a new injector.

Sorry, it's mostly process of elimination.

materialdistractions · 10-12-2011, 12:19 AM

Quote:

Originally Posted by themyst

Swap the plug first, if misfires persist, swap coil packs, if misfire moves with the coil pack, you found your problem. If misfire still persists in cylinder 5, possibly need a new injector.

Sorry, it's mostly process of elimination.

+1. I was having misfire issues with cylinder 6 when I first started running stage 2+. I didn't have the issue when I was running stage 1. I replaced all 6 spark plugs and haven't misfired since on stage 2+ aggressive.

135i · 10-12-2011, 12:26 AM

Quote:

Originally Posted by themyst

Swap the plug first, if misfires persist, swap coil packs, if misfire moves with the coil pack, you found your problem. If misfire still persists in cylinder 5, possibly need a new injector.

Sorry, it's mostly process of elimination.

See Jeff, themyst is more than helpful helping out board members

pHo_e92 · 10-12-2011, 08:55 AM

Quote:

Originally Posted by 135i

See Jeff, themyst is more than helpful helping out board members

besides all the arguing its good to see some good quality posts.

mithiral67 · 10-12-2011, 09:36 AM

Stage 1, no misfires, stage 2 agressive, 4 cylinders misfired. 6 new plugs and she's running like a dream.

Its gross getting sideways in first at 50% power, then shifting to 2nd to help traction and still getting sideways at 50% power.

Mike@N54Tuning.com · 10-12-2011, 09:45 AM

Quote:

Originally Posted by themyst

Swap the plug first, if misfires persist, swap coil packs, if misfire moves with the coil pack, you found your problem. If misfire still persists in cylinder 5, possibly need a new injector.

Sorry, it's mostly process of elimination.

+1

Misfires after installing a tune are not uncommon. Just means a certain component is on the way out, and the higher boost just puts it over the edge. Likely culprit is usually the plugs, especially if they have never been changed.

Mike

vasillalov · 10-12-2011, 11:14 AM

How are you guys detecting the misfires? Butt dyno or do your cars throw codes?

themyst · 10-12-2011, 11:17 AM

Quote:

Originally Posted by vasillalov

How are you guys detecting the misfires? Butt dyno or do your cars throw codes?

Car limps and throws an ses light.

Royal Flush · 10-12-2011, 11:17 AM

Quote:

Originally Posted by Mike@N54Tuning.com

Just means a certain component is on the way out, and the higher boost just puts it over the edge.Mike

Wasn't aware of that, good to know!

vasillalov · 10-12-2011, 11:25 AM

Quote:

Originally Posted by themyst

Car limps and throws an ses light.

Cool. That's what I thought. I've not experienced any of this yet, but my car has only 25K miles and the plugs were changed twice already by BMW.

mithiral67 · 10-12-2011, 12:20 PM

Mine was codes and ses. Then just codes. But I could feel them immediately after boost went north of 15psi.

Jeff@TopGearSolutions · 10-12-2011, 12:44 PM

Quote:

Originally Posted by 135i

See Jeff, themyst is more than helpful helping out board members

HA

Yea now that I yelled at him, HOWEVER, a true friend would have told you to change all 6 while you are in their. No reason having 5 old plugs and one good one. (you did say you only got a spark plug).

Anyway if you changed them 6 months ago it might be a coil pack. Those are the easiest to trouble shoot just change the coilpack to another cylinder and see if the misfire moves.

We are all on the same team here.

I hope to see more productive posts and less bickering.

Joshboody · 10-12-2011, 01:07 PM

interested if solved... misfire detection may surface more now since peeps are running higher boost.

enrita · 10-12-2011, 01:16 PM

Quote:

Originally Posted by Joshboody

interested if solved... misfire detection may surface more now since peeps are running higher boost.

we have been running high boost for the past 2 years ;-)

Joshboody · 10-12-2011, 01:24 PM

Quote:

Originally Posted by enrita

we have been running high boost for the past 2 years ;-)

Well the minority went high boost as soon they could, but Cobb is providing this to more people without the need for meth... and then piggies are kinda following suit in a "for the masses" hp race.

vasillalov · 10-12-2011, 02:47 PM

Quote:

Originally Posted by mithiral67

Mine was codes and ses. Then just codes. But I could feel them immediately after boost went north of 15psi.

Thanks James. The symptoms sound exactly what I expected them to be.

mithiral67 · 10-12-2011, 02:56 PM

At first, I was like, this is the throttle plate closure that vasil is feeling, GOD DAMNIT. Then I went SES and knew it was more serious.

Brey335i · 10-12-2011, 02:57 PM

We swapped all 6 plugs a few months ago in the back of COBB's Austin Shop.... They should still be almost brand new.

135i · 10-12-2011, 05:18 PM

Quote:

Originally Posted by Brey335i

We swapped all 6 plugs a few months ago in the back of COBB's Austin Shop.... They should still be almost brand new.

I have no idea how one would go about changing a coil. Shit.

Rob@Cobb · 10-12-2011, 05:21 PM

Quote:

Originally Posted by 135i

I have no idea how one would go about changing a coil. Shit.

It's really easy. Ping me and I can help out.

Cheers,
Rob

Brey335i · 10-12-2011, 07:26 PM

Quote:

Originally Posted by Rob@Cobb

It's really easy. Ping me and I can help out.

Cheers,
Rob

Customer support ftw

10-11-2011, 11:57 PM	#1
135i Cobb Stage 2+/ICarbon/HPF/Stett 40 Rep 488 Posts Drives: E92 335i 6MT Join Date: Aug 2007 Location: Deep in the Heart iTrader: (0)	Cobb Stage 2+ Question I keep getting misfires in cylinder 5 while driving at high boost. I flashed back to Stage 1+ and for the most part the misfires stopped. Is there any qualitative way in knowing whether the injector v. the coil v. the spark plug is crapped out? I bought a new spark plug to swap in as soon as I can find a fricking n54 spark plug tool. My gut says its the spark plug, but honestly I swapped them 6 months ago. gracias!
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10-12-2011, 12:01 AM	#2
themyst Major General 177 Rep 6,631 Posts Drives: '16 MK7 GTI Join Date: Feb 2009 Location: NYC iTrader: (8)	Swap the plug first, if misfires persist, swap coil packs, if misfire moves with the coil pack, you found your problem. If misfire still persists in cylinder 5, possibly need a new injector. Sorry, it's mostly process of elimination. __________________ E90 LCI N54 6AT
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10-12-2011, 09:36 AM	#6
mithiral67 That guy 117 Rep 5,740 Posts Drives: 2015 Cayman GTS Join Date: Jun 2008 Location: Chicago Burbs iTrader: (4) Garage List 2015 Porsche Cayman ... [0.00]	Stage 1, no misfires, stage 2 agressive, 4 cylinders misfired. 6 new plugs and she's running like a dream. Its gross getting sideways in first at 50% power, then shifting to 2nd to help traction and still getting sideways at 50% power.
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10-12-2011, 11:14 AM	#8
vasillalov Mad Linux Guru On The Loose 1121 Rep 5,398 Posts Drives: 2008 335i Sedan, 2023 M3 Join Date: Aug 2009 Location: Chicago, IL iTrader: (5) Garage List 2023 BMW M3 [0.00] 2008 335i E90 [8.00]	How are you guys detecting the misfires? Butt dyno or do your cars throw codes? __________________
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10-12-2011, 12:20 PM	#12
mithiral67 That guy 117 Rep 5,740 Posts Drives: 2015 Cayman GTS Join Date: Jun 2008 Location: Chicago Burbs iTrader: (4) Garage List 2015 Porsche Cayman ... [0.00]	Mine was codes and ses. Then just codes. But I could feel them immediately after boost went north of 15psi.
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10-12-2011, 01:07 PM	#14
Joshboody Lieutenant Colonel 65 Rep 1,708 Posts Drives: pickemuptruck Join Date: Jul 2009 Location: Phoenix, AZ iTrader: (7)	interested if solved... misfire detection may surface more now since peeps are running higher boost.
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10-12-2011, 02:56 PM	#18
mithiral67 That guy 117 Rep 5,740 Posts Drives: 2015 Cayman GTS Join Date: Jun 2008 Location: Chicago Burbs iTrader: (4) Garage List 2015 Porsche Cayman ... [0.00]	At first, I was like, this is the throttle plate closure that vasil is feeling, GOD DAMNIT. Then I went SES and knew it was more serious.
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10-12-2011, 02:57 PM	#19
Brey335i Banned 112 Rep 4,771 Posts Drives: e46 ///M3 Join Date: Oct 2009 Location: Austin, TX iTrader: (11)	We swapped all 6 plugs a few months ago in the back of COBB's Austin Shop.... They should still be almost brand new.
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