[Camaroguy555]

Does anyone else have the issue when cold of the car holding rpm on a slight rev? I'll pull out of a parking spot when the vehicle is cold (maybe let it run for 15 seconds first) and when I crack the throttle the rpms climb and hold about 2500 even when off throttle.

[mjk3888]

Originally Posted by JDP Sales

Mine can be felt in the car as well when it's cold. It goes away after the car drops RPMs to normal idle. If the car truly had a misfire, the CEL would be on.

All the best,

Jared Royce

This had been brought up in another thread a while back and I commented that in my experience as a Mechanic while I was attending school. Modern OBDII equipped cars have misfire counters and a CEL will only come on if the misfires exceed a preset amount in a certain time span. A car with 90 misfires in 5 minutes might set a light, A car with 90 misfires in 5 days will not. Misfires happen a lot more often than you might think but usually not at idle in a brand new car.

Originally Posted by tecmec

I've had the same thing for my last two trips. Not just a rough idle, not just a few misses while idling, but even a few misses under light acceleration. It's pretty obviously a miss, because you can feel the car hesitate while you're in the middle of accelerating. I've got 3000 miles on the car, and it only just started doing this. It used to idle a little rough when cold, sure, but that wasn't this.

I did notice that I only had about a quarter tank of gas, and I remembered the post where the guy "ran out of gas" with an eighth tank remaining (as confirmed by his fuel gauge and the amount of fuel it took to fill back up). I figured I may have actually had some air in the fuel line causing the miss.

Maybe there's an inherent fuel pickup problem in these cars? How much gas do you guys have in the tank when your car is missing?

You could be onto something. Its possible all these cars were suffering from fuel pick up issues with a lower fuel level. All I know is if there is an underlying issue, I hope GM finds and solves it before my 2017 1LE is built.

[stars_fan]

Originally Posted by JDP Sales

Not a misfire. Its just the cam lope that you hear at a specific rpm. Mine does that too. So have the other 16's we've had here. That sound is just "Merica" flowing from your exhaust

All the best,

Jared Royce
801.545.4215

[Algeron]

Originally Posted by banter

Nah, definitely a misfire. Whole car shakes, if car is moving it's a noticeable jolt.

I have the same issue. Even my kids (6 and 8) asked why the car acted that way in the mornings.

[Lemosine]

I remember when my 06 GTO always did it at a complete stop.

[EFI]

Nah, definitely a misfire. Whole car shakes, if car is moving it's a noticeable jolt.

How can you be 100% sure it's a missfire? Do you get codes for that?

Have you ever been in another big American V8, especially one with a larger than stock cam? That's exactly how those are, even on the stock cam and especially in an auto which tend to idle much lower than manuals (eg somewhere in the 5-600rpm range).

Big V8 idling that low, especially in the cold, is going to rock. A true missfire is much worse and you would hear the car run like shit. That's different than engine rock.

[Tr6]

LT1 doesn't love cold start that much but what you are hearing is just Freedom Flowing through your exhaust! Just like Jared said! Also here:
http://www.camaro6.com/forums/showthread.php?t=430867

[gippy87]

Everyone keeps saying it's the big cam but on my built ls1 with a much more agressive cam I can start it at the same time and don't have any noticeable misses like I do with the camaro. Seems to be more noticeable in colder Temps.

[Camaroguy555]

Originally Posted by Camaroguy555

Does anyone else have the issue when cold of the car holding rpm on a slight rev? I'll pull out of a parking spot when the vehicle is cold (maybe let it run for 15 seconds first) and when I crack the throttle the rpms climb and hold about 2500 even when off throttle.

Yes, my car does this all the time and actually gets a little scary at times because it will accelerate out of nowhere with light throttle application. I guess I need to let it warm up longer?

[camarouwe]

Also had bad misfiring when i picked up my new Camaro yesterday.
----Cold and hot---!
Drove 500 mls yesterday, started my beauty today, everything was fine,
no misfiring at all, premium gas and a proper run in should solve this problems.
I also notived a much more free rev up from the engine after this 500 mls.
Lets see and wait if misfiring comes back, i dont hope so.
If ignition and fuel management is o.k. , the only cause of misfiring can be insufficient compression or bad fuel.

All the best from good old Germany

Uwe

[fastball]

On modern cars if ANYTHING was misfiring or not firing properly you'd have a check engine light and codes.

You don't. Relax. Your car is fine.

[SuperSound]

Not sure but cold start DI tuning causes rough idle and possibly stumbling. It's perfectly normal and remember these engines do not heat up that quick with all the cooling in place.

Sent from my SAMSUNG-SM-G920A using Tapatalk

[kasperdsmk]

I have an idea, let your car fully warm up to operation temperature before you drive it. say like 7-10 mins vs. 15 seconds. I promise your problems will go away. (maybe not go away but you wont notice them when your in the house drinking coffee before work) seriously though are all you guys using premium like is recommended? Depending on your location the fuel could still be summer blend Vs a winter blend... or a shady gas station selling you crap vs real 93 I've ran into it before on performance cars that were finely tuned and acted funny with gas from shady stations

[Goal seeker]

Definitely a misfire. I just picked up my new 17 1SS on Saturday, and it ran great. I started it yesterday after its first detail (117 miles on the car), and was caught off guard by the misfire. You can definitely "feel" it. I had a 70 Chevelle with a aggressive small block in it, I know the difference between rough cam idle and a misfire (Isky 304 Mega). As soon as the engine built some temperature it went away. This was only idling in the garage. I did not drive it.