Rough idle...

[Coyotekiller]

So my camaro has had this issue since I got it, but its finally getting slightly annoying. The car idles around 500-575 and fluctuates constantly. It's very noticeable and I wanna try to get it smoothed out before I decide on an exhaust for the car.

Oh and going to the dealer isn't gonna help me much seeing as how the car is tuned now with a cold air intake installed. So they will just say my tune is causing it and I'm stuck fixing it anyway.

I just wanna know what could be causing the rough idle and what I can do to fix it.

[Higgs Boson]

it can be fixed in tune. mine was like that so I adjusted some things and now it doesn't move a bit. stock doesn't mean perfect. even the factory calibration can be improved in many areas.

[SC2150]

Agreed. get a tuner that has the skill to tune it correctly.

[NC-V]

Originally Posted by SC2150

Agreed. get a tuner that has the skill to tune it correctly.

+1 Should idle nice and smooth... unless you cammed it. In stock trim you should be able to idle at a steady 525.

[Nitroman28]

Originally Posted by Coyotekiller

So my camaro has had this issue since I got it, but its finally getting slightly annoying. The car idles around 500-575 and fluctuates constantly. It's very noticeable and I wanna try to get it smoothed out before I decide on an exhaust for the car.

Oh and going to the dealer isn't gonna help me much seeing as how the car is tuned now with a cold air intake installed. So they will just say my tune is causing it and I'm stuck fixing it anyway.

I just wanna know what could be causing the rough idle and what I can do to fix it.

When driving at a steady speed does it surge?

[Higgs Boson]

Originally Posted by Nitroman28

When driving at a steady speed does it surge?

he is just complaining about the normal stock rough idle. I don't think he has a cam and should not have an issue with idle airflow or throttle follower. the issue with the stock cal is mostly timing.

[Coyotekiller]

No cam and it's not surging at speed. What would you guys look to in the tune to correct this?

[Higgs Boson]

spark timing tables

[NC-V]

You want to look at your Idle spark advance. From the factory, the idle timing is quite low, and as Higgs stated is what largely contributes to the rough idle. Play around raising the idle timing until you are happy with the result.

Are you doing the tuning? If so what software/device are you using?

[Coyotekiller]

Originally Posted by NC-V

You want to look at your Idle spark advance. From the factory, the idle timing is quite low, and as Higgs stated is what largely contributes to the rough idle. Play around raising the idle timing until you are happy with the result.

Are you doing the tuning? If so what software/device are you using?

I'm gonna have a buddy of mine do it probably. He uses HP tuners. So just add spark advance until it smooths out? Is that gonna affect anything once the throttle is opened? Or is that just idle timing?

[NC-V]

It won't affect anything except idle. Have him look at the Base Idle spark advance table (if he tunes regularly he probably already knows this). He can use the ON-OFF functions in the scanner to play with the idle timing in real time so you don't have to keep changing the tune to get it right.

[Higgs Boson]

pretty sure the scanner only allows you to retard the timing, not advance it, haven't had to mess with it in a while for that.....the older ecms could go both ways. he might have to raise idle spark like 7 degrees and then back it down. you do not want the most timing you can get because then the overspeed and under speed won't work right.....

just pm me if you guys can't get it, you can email me the file and I'll look at it for you.

[NC-V]

Originally Posted by Higgs Boson

pretty sure the scanner only allows you to retard the timing, not advance it, haven't had to mess with it in a while for that.....the older ecms could go both ways. he might have to raise idle spark like 7 degrees and then back it down. you do not want the most timing you can get because then the overspeed and under speed won't work right.....

just pm me if you guys can't get it, you can email me the file and I'll look at it for you.

Yeah, it only allows you to retard on these ecms so he would have to set it high in the tune and retard it and see where the sweet spot is (forgot about that, good catch Higgs), remember to do it with the a/c on also.

[Coyotekiller]

What do you mean set it higher? The idle spark advance?