C6 ls2 6sp car ECS sl1500 kit
I have been troubleshooting and been having trouble figuring it out.
Car starts up fine. Stutters when reving it slowly sometimes and other times it revs fine. Then while driving it seems fine then out of no where theirs the studdering I guess is a good choice of wording.
It has 60lb fuel pressure and I didnt find any loose vac hoses. Spark plugs are good and wires are snug.
Any ideas are suggestions are appreciated.

I'm woundering if it is maf or tailq bov or even the O2's
No cel light either.

 

Speed density tuned?

 

Way too many things it could be. Need more data. Log it and post a log as it studders.

Could be tune, spark, maf, leak, bov, TB issues, etc etc.

 

I had similar situation that was intermittent and found poor connection to one of the injectors

 

Here is a Data log. Can someone please take a look. The headers on both sides are glowing now.

Started with very slight sporadic stumbling. To more frequent stumbling. Now to consistent stumble my first thought was spark.

January
Changed plugs
Changed Oil/Fresh good gas
found/replaced broken ECS tensioner bolt
Cleaned catch can
Found broken vacuum T at master cylinder going to boost gage.
Still intermittent stumble

February 1st
Pulled plugs still looked new
Ohm tested coil packs on passenger side/all read similar and MSD wires while doing this I noticed dry rotten capped passenger valve cover vent and replaced cap.
Rechecked all vacuum lines as suspect MSD BAP to T, T to boost gage valley cover,throttle body,T to blow off valve ect.
Cleaned/Inspected mass air
Removed and checked BOV spring on intercooler
Checked restrictor plate/air filter.
62lbs on the rail

February
Car now Stumbles after 5-10 min of idle after hot.

I then noticed the glowing headers more on the passenger side than driver but both sides glow eventually. The rear 2 passenger seem to glow first after further inspection.
Kooks high flow cats mid pipe suspect now. So I removed mid pipe and inspected cats.
The looked brand new and when you shine led light it shines right through unlike comparing cats I pulled off this ctsV the other day no light passing through. I reinstalled them and then data logged idling and holding 1500,2500 and a few revs.
I ran mid pipe no mufflers still cherry reduced

Also smoke tested it. No leaks found

 

i had a weird issue like that happening very rarely and turned out to be bad connection in a throttle body harness extension, but could be anything really, i'd probably check all the grounds too

 

Car has been fine for 2years on tune until this.

 

Check for broken valve spring.

 

I did lift covers and inspect springs and rockers. All looks good.

 

Bump for fix. Currently having similar issue..

 

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