Cold start misfires. I think this is more serious than I thought! - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

bmorecam · 03-10-2012, 08:04 PM

I am freaking disappointed/angry/worried as I don't know WTH is going on right now

. I'm not sure if this is related to the new cam phase adjustment testing me and vince been doing for these last few months, but like a month after I been driving with the new tune, every now and then my car would choke, bog, and basically act like couple cylinders are not firing only during cold start, but as soon as the rpm come down, it would be as smooth as butter like the hard start did not even occur and no CEL.
Anyway, just a few days ago it happened again, but this time I got a CEL for multiple misfire on cylinder 2 and 5. I cleared the code and reverted back to the old tune, the next morning it happened again, another CEL for misfire during cold start, I cleared the code and decided to run some techron fuel system cleaner, the next cold start was ok, the cold start still seemed a little rough than usual but no CEL and not as boggy and no choking. cold start again just about an hour ago but this time I monitored the misfires in real time, cold start was ok as before, a little rough than usual again but no CEL, but the crazy thing is that I am seeing 34 misfires in cylinder 1 and couple on all cylinders. No CEL yet but there was a pending misfire CEL on cylinder number 3 this time.

I need some help from you guys this time. It seem this is only happening during cold start only. After the initial cold start everything is smooth as butter with not even 1 misfire on any of the cylinders. If I had to guess it look like a problem that is persisting, but I don't know what it could be

I need your expertise on this guys.

Kmorpheus · 03-10-2012, 08:16 PM

Do you think you could be experiencing a timing chain problem? Just a thought that occured to me, after reading about some of the blown engine reports.

bmorecam · 03-10-2012, 08:17 PM

I don't know, I thought about that but what are timing chain symptoms?

Blade · 03-10-2012, 08:17 PM

1) Time to get the injectors checked out.
Or
2) Bad seals in the cylinders?

If this stuff keeps happening, sooner or later you gonna get some knocking probably, take it to the dealer fast.

Also, did you install the tune right after the insulators? I don't think the ported IM would be an issue, because I think you had that done for a long time now.

scrming · 03-10-2012, 08:20 PM

Pull any of the plugs? Compression check?

bmorecam · 03-10-2012, 08:26 PM

Quote:

Originally Posted by Blade

1) Time to get the injectors checked out.
Or
2) Bad seals in the cylinders?

If this stuff keeps happening, sooner or later you gonna get some knocking probably, take it to the dealer fast.

Also, did you install the tune right after the insulators? I don't think the ported IM would be an issue, because I think you had that done for a long time now.

This problem started happening after me and vince been testing the new tune. I really do not want to deal with the dealer right now

Quote:

Originally Posted by scrming

Pull any of the plugs? Compression check?

None yet.. but it look like that will have to be my next step.

WTH could be making my car misfire like this only on cold start tho?? then everything is perfect

Kmorpheus · 03-10-2012, 08:35 PM

If this was not a Direct Injection motor I would recomend testing out the fuel pump. Do you have a way to tell if the fuel delivery system is having some issues getting fuel up to pressure after it has sat.

bmorecam · 03-10-2012, 08:39 PM

I already checked the HPFP fuel pressure and it's normal, oil pressure normal.

formare · 03-10-2012, 08:42 PM

You might try going back to factory tune then loading in a later tune without the cam phasing. Or you could force a full write tune. It could be you loaded a few tune files that are tweaking only part of the configuration file that is in conflict with some other modified table.

Just a wild guess.

Blade · 03-10-2012, 08:43 PM

Quote:

Originally Posted by bmorecam

This problem started happening after me and vince been testing the new tune. I really do not want to deal with the dealer right now

None yet.. but it look like that will have to be my next step.

WTH could be making my car misfire like this only on cold start tho?? then everything is perfect

With my recent electrical issues, I am having similar issues, not misfires, but the experience is very similar.

The car won't cold start right away, starter acts real sluggish, but then the rest of the day the car works fine. Weird. And the problems only happen when I leave the car overnight.

Have you tried installing the tune that was prior to this new one? Maybe install the stock tune, drive around, and then install the one that was working fine. Stranger things have worked

bmorecam · 03-10-2012, 08:52 PM

The 1st thing I did was to go back to the old tune that everyone has, force full write. That is the tune I am running now and still same misfire. Not sure if the problem started with the new tune we been testing or this is a problem that was going to happen, I have no clue. I'm just scared that I burned one of my pistons or valves from running too much dynamic compression and timing. That would be my worst fear. I don't think so tho because it only happens during that small window during cold start. Some are saying my coil pack might be bad. I do run the dyno alot so maybe my wires are rigged from the rpm pick up sensor???

anyone know how our cylinders line up? which one is cy1, 2 and 5?

bmorecam · 03-10-2012, 09:15 PM

This is bulshyt

I can't believe this is happening to me after I decided to keep her in my life LOL.

rtcat600man · 03-10-2012, 09:27 PM

Quote:

Originally Posted by bmorecam

The 1st thing I did was to go back to the old tune that everyone has, force full write. That is the tune I am running now and still same misfire. Not sure if the problem started with the new tune we been testing or this is a problem that was going to happen, I have no clue. I'm just scared that I burned one of my pistons or valves from running too much dynamic compression and timing. That would be my worst fear. I don't think so tho because it only happens during that small window during cold start. Some are saying my coil pack might be bad. I do run the dyno alot so maybe my wires are rigged from the rpm pick up sensor???

anyone know how our cylinders line up? which one is cy1, 2 and 5?

Sorry to hear about the bad news, Don't give up hope yet. Maybe it is something simple. What are the mis fire codes that it is throwing out.

As for the firing order. I checked on yahoo and this is what came up.

http://*************/forum/viewtopic.php?t=396&p=7537

Trouble is (you see) the ********** is because the other site has the firing order posted. (other site is banned from being listed here)

Back of engine

5 6
3 4
1 2

Front of engine

Good luck and I wll do some more reading and searching.

Kmorpheus · 03-10-2012, 09:34 PM

If you love them they are constantly testing you, just like a woman.

03-10-2012, 08:04 PM	#1
bmorecam Account Suspended Drives: jealous vendors mad!! HAHA!! Join Date: Jan 2011 Location: CYBERGMONSTER@GMAIL.COM Posts: 3,658 View My Garage	Cold start misfires. I think this is more serious than I thought! I am freaking disappointed/angry/worried as I don't know WTH is going on right now. I'm not sure if this is related to the new cam phase adjustment testing me and vince been doing for these last few months, but like a month after I been driving with the new tune, every now and then my car would choke, bog, and basically act like couple cylinders are not firing only during cold start, but as soon as the rpm come down, it would be as smooth as butter like the hard start did not even occur and no CEL. Anyway, just a few days ago it happened again, but this time I got a CEL for multiple misfire on cylinder 2 and 5. I cleared the code and reverted back to the old tune, the next morning it happened again, another CEL for misfire during cold start, I cleared the code and decided to run some techron fuel system cleaner, the next cold start was ok, the cold start still seemed a little rough than usual but no CEL and not as boggy and no choking. cold start again just about an hour ago but this time I monitored the misfires in real time, cold start was ok as before, a little rough than usual again but no CEL, but the crazy thing is that I am seeing 34 misfires in cylinder 1 and couple on all cylinders. No CEL yet but there was a pending misfire CEL on cylinder number 3 this time. I need some help from you guys this time. It seem this is only happening during cold start only. After the initial cold start everything is smooth as butter with not even 1 misfire on any of the cylinders. If I had to guess it look like a problem that is persisting, but I don't know what it could be I need your expertise on this guys.

03-10-2012, 08:17 PM	#4
Blade Drives: 2016 Camaro 2SS BVM Join Date: Dec 2009 Location: Charlotte Posts: 4,689 View My Garage	1) Time to get the injectors checked out. Or 2) Bad seals in the cylinders? If this stuff keeps happening, sooner or later you gonna get some knocking probably, take it to the dealer fast. Also, did you install the tune right after the insulators? I don't think the ported IM would be an issue, because I think you had that done for a long time now. __________________ Formerly owner of: 2012 2SS/RS Build Thread - Totaled by red light runner 2010 LT/RS Build Thread - Traded in for 2012 2SS 2007 Acura TSX 1992 Oldsmobile Achieva V6 1992 Mercury Sable

03-10-2012, 08:20 PM	#5
scrming Red Brick of Vengeance! Drives: 12 Second Brick Join Date: Jun 2009 Location: at my pulpit Posts: 7,745	Pull any of the plugs? Compression check? __________________ 2011 Ford Flex EcoBoost Limited - 12.727 @ 109.790 MPH

03-10-2012, 08:42 PM	#9
formare The Milano Drives: 2017 Firefly ShipWorks Join Date: Jun 2010 Location: Chicagoland (Crown Point, IN) Posts: 1,877 View My Garage	You might try going back to factory tune then loading in a later tune without the cam phasing. Or you could force a full write tune. It could be you loaded a few tune files that are tweaking only part of the configuration file that is in conflict with some other modified table. Just a wild guess. __________________ My first Love. She was called "Miss Carriage" (still cry when I think about her) 383, Muncie 4 speed, custom linkage mated to hurst short throw shifter.

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03-10-2012, 08:16 PM	#2
Kmorpheus Account Suspended Drives: Green Dream Machine Join Date: Mar 2011 Location: Waterloo, IA AUN Posts: 296 View My Garage	Do you think you could be experiencing a timing chain problem? Just a thought that occured to me, after reading about some of the blown engine reports.

03-10-2012, 08:35 PM	#7
Kmorpheus Account Suspended Drives: Green Dream Machine Join Date: Mar 2011 Location: Waterloo, IA AUN Posts: 296 View My Garage	If this was not a Direct Injection motor I would recomend testing out the fuel pump. Do you have a way to tell if the fuel delivery system is having some issues getting fuel up to pressure after it has sat.

03-10-2012, 08:39 PM	#8
bmorecam Account Suspended Drives: jealous vendors mad!! HAHA!! Join Date: Jan 2011 Location: CYBERGMONSTER@GMAIL.COM Posts: 3,658 View My Garage	I already checked the HPFP fuel pressure and it's normal, oil pressure normal.

03-10-2012, 08:52 PM	#11
bmorecam Account Suspended Drives: jealous vendors mad!! HAHA!! Join Date: Jan 2011 Location: CYBERGMONSTER@GMAIL.COM Posts: 3,658 View My Garage	The 1st thing I did was to go back to the old tune that everyone has, force full write. That is the tune I am running now and still same misfire. Not sure if the problem started with the new tune we been testing or this is a problem that was going to happen, I have no clue. I'm just scared that I burned one of my pistons or valves from running too much dynamic compression and timing. That would be my worst fear. I don't think so tho because it only happens during that small window during cold start. Some are saying my coil pack might be bad. I do run the dyno alot so maybe my wires are rigged from the rpm pick up sensor??? anyone know how our cylinders line up? which one is cy1, 2 and 5?

03-10-2012, 09:15 PM	#12
bmorecam Account Suspended Drives: jealous vendors mad!! HAHA!! Join Date: Jan 2011 Location: CYBERGMONSTER@GMAIL.COM Posts: 3,658 View My Garage	This is bulshyt I can't believe this is happening to me after I decided to keep her in my life LOL.

03-10-2012, 09:34 PM	#14
Kmorpheus Account Suspended Drives: Green Dream Machine Join Date: Mar 2011 Location: Waterloo, IA AUN Posts: 296 View My Garage	If you love them they are constantly testing you, just like a woman.