Cylinder misfire - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Mach · 04-22-2012, 09:48 AM

Quote:

Originally Posted by cjon9657

What I don't understand is it only acts up at cold start first thing in the morning. I notice no misfiring while I'm driving or loss of power and it does not do it at any other cold start thru ought the day.

I had a multiple misfire CEL pop up once during startup two winters ago. It was cold as shit. Like 4 degrees.

This leads me to believe my problem was different from what you guys are going through.

The dealer told me there is new software for really cold starts. Something about raising the choke rpm during the cat warmup phase. So the engine doesn't bog down during the really cold starts.

Take it to the dealer. Describe what is happening. Hopefully they can help you despite having Longtubes.

TooCool5 · 04-23-2012, 10:42 AM

My car does the same thing only when it is below 20 degree's out.

Now that spring is here it is smooth as silk on cold starts.

Re flash did not correct my cold start rough idle.

Mach · 04-23-2012, 10:45 AM

Quote:

Originally Posted by TooCool5

My car does the same thing only when it is below 20 degree's out.

Now that spring is here it is smooth as silk on cold starts.

Re flash did not correct my cold start rough idle.

All cars have a rough idle when started when its below 20 degrees out. The reflash is supposed to fix the cylinder misfire CEL. Question is do you get a cylinder misfire CEL after the reflash?

GMGP5X · 04-23-2012, 05:50 PM

Had the cold start misfire problem about 4 months ago. Took it in they did the reflash and has been fine since then.

bmorecam · 04-23-2012, 06:45 PM

I really wish I knew what it is that they exactly change in the reflash so I can get vince to tweak mine for me:(

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cjon9657 · 04-23-2012, 06:50 PM

Im going to try to get a video of my car at start up in the morning if i can remember.

bmorecam · 04-23-2012, 07:57 PM

Quote:

Originally Posted by cjon9657

Im going to try to get a video of my car at start up in the morning if i can remember.

does your idle bounce up and down with rough idle in the morning? I always don't get a misfire but is definitely not a normal rough idle either. This thing sound like it has a big arse cam in it for that 20-30 seconds. I'm going to try to get a video too for you guys.

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cjon9657 · 04-23-2012, 08:02 PM

Yes it does bounce up and down at idle. I just got done cleaning my mass air flow sensor and it has ran better than ever. BUT i wont really know until first thing in the morning.

cjon9657 · 04-23-2012, 08:03 PM

Knock on wood.

bmorecam · 04-23-2012, 08:23 PM

Sound like we have the same issue brother LOL. I did all that. From cleaning my maf to seafoam. It would act like its running fine but it all comes back. I think its more of a mind thing after when we change our oil and clean the maf and such, who knows

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cjon9657 · 04-23-2012, 08:46 PM

haha you are probably right.

cjon9657 · 04-24-2012, 06:01 PM

You were so right! Lol. Although it has not sounded as bad the last two mornings with the warmer temp. Last thursday through sunday in the morning it was misfiring so bad i didnt know what to think and that was when the temperature was in the low 30s.

RS Speedriver · 09-23-2014, 11:12 AM

well mine mirfires and throws engine code po300 and 304. idle is kinda rough. i can feel movement. and feel loss of power when acc. when coming to stop sometimes rpms drop and go up and down a bit. then when getting rdy to go. stability trek comes on. i turn off car for a min or so and start it up. all lights are gone but there is jerking when car is slowing down in every gear till fully stopped. so now at dealership for them to tell me what the problem is. did a sea form test. changed to plugs. changed gas stations. and still does the same thing. i an out of ideas.

InfernoMan2011 · 03-20-2015, 04:22 PM

I just ran across this thread and it sounds like the issue I am having. On my way home from work 2 days ago, the CEL just randomly came on and has stayed on ever since. I just hit 43300 miles on my 2011 V6 LT. I need to take it in to the dealership anyway to have them update the software on the PDIM module, occasional "Trunk Open" notice on the DIC when the trunk is closed, and the two recalls for Drivers Side lower seat frame bolt & ignition/key issue. I stopped by O'Reilly's on the way home from work to have them read the code and it came back as a "Cylinder 1 Misfire". I'm going to pick up some Seafoam and do some cleaning and clean the MAF sensor also. I'm wondering if I might need a reflash also. Does anybody know the TSB for this issue? or a good place to find TSBs. I'd like to know them to provide them to the service dept. when I arrive. I've found a lot of times they don't know about certain TSBs.......

As far as the Seafoam treatment goes, do I want to get the spray and do the upper engine cleaning? I know you can also add it to the crankcase and fuel system. Should I do all 3 of these? and if so, at different times?

04-23-2012, 10:42 AM	#16
TooCool5 Drives: 2010 Camaro 1LS 3.6 LLT V6 325 HP Join Date: May 2009 Location: LS Posts: 4,242 View My Garage	My car does the same thing only when it is below 20 degree's out. Now that spring is here it is smooth as silk on cold starts. Re flash did not correct my cold start rough idle. __________________ 2010 Camaro Auto, Inferno Orange, Titanium Interior, Gearhead Wheels AIRAID CAI

04-23-2012, 05:50 PM	#18
GMGP5X Drives: 2011 2LT RS VR 2008 Silverado 2500 Join Date: Sep 2010 Location: Florissant,Mo Posts: 580 View My Garage	Had the cold start misfire problem about 4 months ago. Took it in they did the reflash and has been fine since then. __________________ 2LT RS VR / ARK DTS Cat back exhaust / Roto-Fab CAI / RPI stealth mud guards /Defender works billet chrome door sills/ DIY painted engine cover, trunk corners, and brake rotors / RX catch can / Team LLT badges. Team LLT

03-20-2015, 04:22 PM	#28
InfernoMan2011 Drives: 2011 Inferno Orange 1LT Join Date: Apr 2011 Location: Arkansas Posts: 199 View My Garage	Same issue.... I just ran across this thread and it sounds like the issue I am having. On my way home from work 2 days ago, the CEL just randomly came on and has stayed on ever since. I just hit 43300 miles on my 2011 V6 LT. I need to take it in to the dealership anyway to have them update the software on the PDIM module, occasional "Trunk Open" notice on the DIC when the trunk is closed, and the two recalls for Drivers Side lower seat frame bolt & ignition/key issue. I stopped by O'Reilly's on the way home from work to have them read the code and it came back as a "Cylinder 1 Misfire". I'm going to pick up some Seafoam and do some cleaning and clean the MAF sensor also. I'm wondering if I might need a reflash also. Does anybody know the TSB for this issue? or a good place to find TSBs. I'd like to know them to provide them to the service dept. when I arrive. I've found a lot of times they don't know about certain TSBs....... As far as the Seafoam treatment goes, do I want to get the spray and do the upper engine cleaning? I know you can also add it to the crankcase and fuel system. Should I do all 3 of these? and if so, at different times?

04-23-2012, 06:45 PM	#19
bmorecam Account Suspended Drives: jealous vendors mad!! HAHA!! Join Date: Jan 2011 Location: CYBERGMONSTER@GMAIL.COM Posts: 3,658 View My Garage	I really wish I knew what it is that they exactly change in the reflash so I can get vince to tweak mine for me:( Sent from my LG-P500 using Tapatalk

04-23-2012, 06:50 PM	#20
cjon9657 Drives: 2017 2LT RS Join Date: Jun 2011 Location: Manhattan, KS Posts: 480 View My Garage	Im going to try to get a video of my car at start up in the morning if i can remember.

04-23-2012, 08:02 PM	#22
cjon9657 Drives: 2017 2LT RS Join Date: Jun 2011 Location: Manhattan, KS Posts: 480 View My Garage	Yes it does bounce up and down at idle. I just got done cleaning my mass air flow sensor and it has ran better than ever. BUT i wont really know until first thing in the morning.

04-23-2012, 08:03 PM	#23
cjon9657 Drives: 2017 2LT RS Join Date: Jun 2011 Location: Manhattan, KS Posts: 480 View My Garage	Knock on wood.

04-23-2012, 08:23 PM	#24
bmorecam Account Suspended Drives: jealous vendors mad!! HAHA!! Join Date: Jan 2011 Location: CYBERGMONSTER@GMAIL.COM Posts: 3,658 View My Garage	Sound like we have the same issue brother LOL. I did all that. From cleaning my maf to seafoam. It would act like its running fine but it all comes back. I think its more of a mind thing after when we change our oil and clean the maf and such, who knows Sent from my VTAB1008 using Tapatalk 2

04-23-2012, 08:46 PM	#25
cjon9657 Drives: 2017 2LT RS Join Date: Jun 2011 Location: Manhattan, KS Posts: 480 View My Garage	haha you are probably right.

04-24-2012, 06:01 PM	#26
cjon9657 Drives: 2017 2LT RS Join Date: Jun 2011 Location: Manhattan, KS Posts: 480 View My Garage	You were so right! Lol. Although it has not sounded as bad the last two mornings with the warmer temp. Last thursday through sunday in the morning it was misfiring so bad i didnt know what to think and that was when the temperature was in the low 30s.

09-23-2014, 11:12 AM	#27
RS Speedriver Drives: 2018 camaro 1ss 1LE Join Date: Apr 2013 Location: B.C. Pitt Meadows Posts: 305 View My Garage	well mine mirfires and throws engine code po300 and 304. idle is kinda rough. i can feel movement. and feel loss of power when acc. when coming to stop sometimes rpms drop and go up and down a bit. then when getting rdy to go. stability trek comes on. i turn off car for a min or so and start it up. all lights are gone but there is jerking when car is slowing down in every gear till fully stopped. so now at dealership for them to tell me what the problem is. did a sea form test. changed to plugs. changed gas stations. and still does the same thing. i an out of ideas.