Rough idle

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Apr 26, 2023 | 12:44 AM

msaldivar

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Rough idle

My 2014 with 19,000 miles recently developed a bit of a rough idle. Not severe, but I can feel it.
Can anyone give me an idea of what to check?

Apr 26, 2023 | 10:07 AM

CorvetteMike2024

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Any codes?

Apr 26, 2023 | 10:14 AM

msaldivar

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No CEL. Just a tad rough.

Apr 26, 2023 | 10:29 AM

squirrelchew

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From: MSP

shaking at idle is considered normal for the c7, unfortunately.

Apr 26, 2023 | 10:33 AM

eboggs_jkvl

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I'd check the plug wires to make sure one of them has worked it's way loose.

Elmer

Apr 26, 2023 | 10:54 AM

msaldivar

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Will do. Thanks Elmer.

Apr 26, 2023 | 11:04 AM

msaldivar

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I get that, but I've owned this car since new and it just feels a bit rougher than normal.

Apr 26, 2023 | 11:28 AM

mbaessler

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I know if I could just add about 100RPM to my idle it would idle smooth. I think mine idles at 590RPM preset at the factory. Can't change it. Also could it be your gas? Inconsistant fuel quality? Sounds like it is out of norm for you.

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Apr 26, 2023 | 11:38 AM

Vetteman Jack

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Have you recently filled the car up with gas and perhaps got some with water in it? A little rough idle is normal - been that way since at least the C5.

Apr 26, 2023 | 12:57 PM

#10

msaldivar

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Yup...recent fill up. Noticed it after sitting a couple of weeks. Will have to run through this tankful and see. Thanks

Apr 26, 2023 | 01:48 PM

#11

Blackwater0323

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From: NC

Quote:

Originally Posted by mbaessler

Bumped mine to 750-800 rpm with Diablo I3. Really helps the roll off from a stop.

Apr 26, 2023 | 01:53 PM

#12

mbaessler

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Blackwater: So when you bumped the idle, did you get any codes. Does it invalidate warranty. I have a manual also and a better roll out would be nice.

Apr 26, 2023 | 03:29 PM

#13

Scooter NYY

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From: Massachusetts

I have a 2014 Vette Z51. It idles a bit rough. It was worse before I took it in for a full service including a tune-up. It seems that it had a fouled plug. You might want to check that out.

Apr 26, 2023 | 09:00 PM

#14

aklim

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From: Hartford WI

Quote:

Originally Posted by mbaessler

Blackwater: So when you bumped the idle, did you get any codes. Does it invalidate warranty. I have a manual also and a better roll out would be nice.

It shouldn't throw a code if you set the base idle correct. HOWEVER, you did reprogram the ECM so anything the ECM touches might be an issue. IOW, if your wheel cracks, probably not an issue. OTOH, if it is something they can blame to the ECM, you get to fight it.

Apr 27, 2023 | 07:59 AM

#15

Tinkertech

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From: North Texas

Diablo I3 leaves no trace on the ECM.

If returned back to stock tune nothing shows that it was tuned.

Apr 27, 2023 | 12:11 PM

#16

squirrelchew

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From: MSP

Quote:

Originally Posted by mbaessler

I know if I could just add about 100RPM to my idle it would idle smooth.

I know this is true on an ls3 in a camaro, but it definitely isn't true on my c7gs.

Apr 27, 2023 | 12:27 PM

#17

Rbohno

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From: Iron Station, NC

Quote:

Originally Posted by Tinkertech

Diablo I3 leaves no trace on the ECM.

If returned back to stock tune nothing shows that it was tuned.

I am not sure that is correct, I think any tune leaves cookies that the dealership can see regardless of brand.

Apr 27, 2023 | 12:45 PM

#18

eboggs_jkvl

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Diablo claims to leave no trace after it's tune is removed from the ECM. I haven't seen, read, or heard of this not being true.

ELmer

Apr 27, 2023 | 12:53 PM

#19

Blackwater0323

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From: NC

Quote:

Originally Posted by mbaessler

Blackwater: So when you bumped the idle, did you get any codes. Does it invalidate warranty. I have a manual also and a better roll out would be nice.

No codes. Also added a Soler TB & Controller. Finished up with a Diablo Lew email tune. The car is very enjoyable to drive.