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Off Idle Hesitation Stumble

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Not a vacuum leak. Sounds like it and that’s what i initially thought. But I’ve smoke tested it twice. The last time for over an hour pulling on hoses and trying to find something. Idle vacuum is 19.5-20.5. Unless I’m smoke testing wrong. Supposing it is a vacuum
Leak I missed, would this cause the off idle stumble as well or just the misfires?
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Did you smoke test the CAI? If the CAI itself is leaking after the MAF sensor it could cause your problems.

Like I said I don't see this in the logs but it is easy to eliminate or you could get lucky.
 
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I did not smoke test the air intake. From the TB back I guess.
When you looked at the logs, anything else stick out? You thought the cams may be delayed?
 

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I was seeing some lag on the intake cams. I also saw some lag in the TB, pedal was pushed then after a slight delay the TB opened.

BUT

This could be explained by the number of channels (PID's) being logged. This is why I wanted to see logs with 5 or 6 PID's only
 
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I was seeing some lag on the intake cams. I also saw some lag in the TB, pedal was pushed then after a slight delay the TB opened.

BUT

This could be explained by the number of channels (PID's) being logged. This is why I wanted to see logs with 5 or 6 PID's only
Yea gotcha.
I didn’t realize logging all the PIDs would slow things down. I figured they would be instantaneous. That is the log file from Lund. I’m sure I can make a custom
Log file but has to wait till spring. Was hoping to have it fixed by then lol.
By what Mike said, it’s not likely the VCT are causing the issues with his test of cam timing. I just don’t know what I’m chasing here.
 

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I've got my cams set to not move in the off idle to low load areas. That stopped a bit of a stumble for me. Just like back when I was tuning carbs and distributors, each engine likes things a bit different.
 
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Interesting. What was your stumble like?
 

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Just a slight hesitation or it felt like a dead spot in the throttle. It's hard to describe. It was slight, I'd say most people wouldn't notice it but I am real sensitive to what the car does and what I tell it to.
 
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Yea. Mine is a little more than that. When passengers notice the car has issues, it’s a big issue.
 
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Question. The smoke tests I last did were really long. Would there be any risk of the smoke gumming something up inside the motor? Thinking out loud, if the smoke did make things sticky, what would be involved? I am assuming injectors, possibly VCT, TB. If things were gummed up, what is the best way to get rid of it? Would seafoam in the oil work? Would / could you spray it through the intake? It would go through the blower then though. Just thinking if things were sticky, it would make sense for the VCT delay among others

Not saying this is it, but it could be.

Any thoughts on this?
 

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Nah, the smoke didn’t gum up anything, especially vct.
Thanks.
Didn’t figure it did, but right now looking for any possibilities.
There’s plenty of threads on misfires. Nothing really on the idle hesitation, at least not that I can find.
Can’t wrap my head around on it.
 

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What TB is on it?
 
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Stock and then Soler Performance. No change between the two.
 
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Bumping this back up.


Getting ready to plan my next moves and hoping someone has some more insight on what I’m missing getting this solved.

Thanks!!
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