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Running Rough at Idle

Old 12-28-2018, 08:13 PM
  #61  
Street Rat
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Did the Seafoam top end cleaner. Soaked for about fifteen minutes. Drove it aggressively as the instructions stated. Nothing in the way of any smoke came out. Back to the house and it's got the miss still.

Popped the hood in the dark garage and ran it. No light shows at all.
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Old 12-28-2018, 09:06 PM
  #62  
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EWMA is "Exponentially Weighted Moving Average"...not something on my scan tool but I think it's basically an average of your misfires over time...the number can go up or down over time...so Seafoam didn't work ??...I'm not familiar with your Actron scan tool but do those misfires increase at idle or under load ??...it looks like maybe cylinder 5 and 6 are the culprits...do the EWMA numbers increase at idle or under load ??.you said the plugs and wire were changed...usually coil packs are pretty bulletproof...you can recheck those plugs and make sure not might not have been cracked during installation....pretty easy to do...are the plug wires FIRMLY seated...I've seen some that were not....injectors were cleaned and tested I hope so we can rule that out...maybe check that you have system voltage at all the injector feed wires...they are the wires that are all the same color ...long term fuel trims are good now ??.if you can't verify which cylinder or cylinders are misfiring maybe do a compression test to rule out anything mechanical !!...I know it's frustrating but without diagnostic equipment this is just hit and miss !!
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Old 12-29-2018, 10:02 AM
  #63  
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Rob I appreciate you sticking with me.

More info later today.
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Old 12-29-2018, 10:23 AM
  #64  
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Originally Posted by Street Rat View Post
Rob I appreciate you sticking with me.

More info later today.
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Old 12-29-2018, 04:28 PM
  #65  
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Today's task involved pulling the plugs for inspection. All plugs looked good although I noted oil on the threads of # 2 and # 7. Put anti seize on the threads and a liberal coating of dielectric grease inside the plug boots. About half way through I realized that I should have been testing compression on each cylinder. Major brain fart.
So everything looked good. Took it out for a test drive to see if it would trip a code. No codes. The gremlin is still there.

Going to decipher live data from the scan tool now.
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Old 12-29-2018, 04:35 PM
  #66  
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I got this EVA red flashing light at the top of the scan tool. But no codes.

I guess it is the EVAporative system?
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Last edited by Street Rat; 12-30-2018 at 10:26 AM.
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Old 12-30-2018, 04:52 PM
  #67  
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I'm beginning to think this is a mechanical issue. I do have some slight valve train noise. I'm progressing to doing a compression check next to see if there is an issue there.

Do these LS3 engines experience valve train issues?
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Old 01-05-2019, 10:45 AM
  #68  
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Sorry I haven't checked in for a while. These holidays really take up your time. I have yet to run the compression test on the car. The car runs it just has the blip at idle.
After all of the code and injector stuff I kind of got burned out. Give me a few days and I'll have some answers. I hope.
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Old 01-09-2019, 01:33 PM
  #69  
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Originally Posted by Street Rat View Post
Sorry I haven't checked in for a while. These holidays really take up your time. I have yet to run the compression test on the car. The car runs it just has the blip at idle.
After all of the code and injector stuff I kind of got burned out. Give me a few days and I'll have some answers. I hope.
I have decided to throw in the towel on this job.
I think the next step is to pull the valve covers and take a look. I'm not ready to tear into it quite yet. The car is a daily driver and I need it. I never did the compression test. I'm going to drive it for a while and see if the symptoms increase.

Thanks for all of the input.

Craig
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Old 01-09-2019, 01:42 PM
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Craig, Don't give up !!....if you don't want to do a compression test try a "cranking compression test" for the time being... maybe rule out a mechanical issue...put the gas pedal to the floor (clear flood crank) and crank over the engine over...listen if the engine cranks over evenly and consistently...you've been around a while....I know you know what it's supposed to sound like !!
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Old 01-11-2019, 07:58 PM
  #71  
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Thanks for the advice.

I'll get it done. Just not now. I'm in a bad place with this car. It's actually my wife's car. She drives a company vehicle. So I'm left this car that I didn't pick out to do daily errands in. The color is red. I'm definitely not incognito. I'd rather not stick out in a crowd. So I'm told that I can't modify the car. The wife says that. Yeah so I'm like tired of HER car!

So I had to rant.
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Old 01-11-2019, 08:22 PM
  #72  
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From my experience and the recount of many members on this forum, some LS3s are known for having a tiny 'lope' when idling. If it's not throwing codes or causing any type of performance loss I'd imagine you're fine leaving it unless it were to progress.

(If I understand correctly, you're saying cleaning the injectors solved the performance issues and now you're just trying to fix the 'blip' during idle? I think you should take a video so we can listen/see what you're dealing with.)

Last edited by Odo; 01-11-2019 at 08:31 PM.
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Old 01-11-2019, 08:59 PM
  #73  
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Originally Posted by Odo
From my experience and the recount of many members on this forum, some LS3s are known for having a tiny 'lope' when idling. If it's not throwing codes or causing any type of performance loss I'd imagine you're fine leaving it unless it were to progress.

(If I understand correctly, you're saying cleaning the injectors solved the performance issues and now you're just trying to fix the 'blip' during idle? I think you should take a video so we can listen/see what you're dealing with.)
I think that's a great idea. My wife got a new camera for Christmas.
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