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Discussion Starter #1
I'm posting a new one here, because I think I'm narrowing down part of my problem.

So when I turn the tune off and run on stock tune and then go WOT I get that same hesitation above 5000rpms as previously described, but with the stock tune my boost will jump around intermittently (like go from 16psi down to 12psi up to 14 then 16 etc.).

This is all happening at the same 5000rpm plus hesitation point I described in a previous thread.

I'm wondering if that sounds like a boost leak/intercooler problem/wastegate issue to anyone? The boost doesn't fluctuate nearly has badly when the trifecta tune is enabled it stays between 23 to 20 psi.

Has anyone else had anything similar happen?
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If things are jumping around, seems like a leak to me. However, you should see it regardless of the tune. Is it jumping around across the RPM range or only above the 5,000 rpm mark?
 

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Discussion Starter #3
It's only above 5,000 rpms. It starts right when I start feeling that hesitation type feeling where it lets up some and then starts pulling again. I think it is happening with the tune enabled, but I don't notice it as much as long as the boost stays at 20psi or above. Really now that I think about it...it is doing the same thing. It starts off with the tune at 23psi then goes between 20 up to 21 etc. So really it is still doing it now that I think about it.

I'm wondering if anyone else has experienced this type of thing. I would think with a boost leak it would just continue to be lower. Is this also a symptom of something being wrong with the wastegate?
 

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Could be timing. Are you scanning your car at all? I mean, a stock tune shouldn't have those kinds of knock issues to pull timing to be that dramatic but could be.

Problem is I can't remember what we covered in your other posts. Always better to continue those so we can go back and reference what we've already covered.
 

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It is hard to read that log as the resolution is only So So. The hesitations may be happening so quickly that we're missing them in the log. Nothing really looks out of place other than the drop in timing at the end of the run.

Actually, what's up with your throttle position? If your foot is to the floor, that should go to a value and never change. It's bouncing between 68 and 69%. That's odd.
 

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Discussion Starter #7
Hmmmm....if the ecu doesn't think I'm gong to wot bc of the throttle signal would that cause a hesitation and intermittent boost readings..
 

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Discussion Starter #8
Holey crap I'm reading about tps sensor symptoms and surging etc.. It sounds really close to my symptoms! I wouldn't think a slight fluctuation would cause that though...Hmmm..I might try that as a quick fix.
 

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Holey crap I'm reading about tps sensor symptoms and surging etc.. It sounds really close to my symptoms! I wouldn't think a slight fluctuation would cause that though...Hmmm..I might try that as a quick fix.
That slight fluctuation could definitely be felt at WOT as a "hesitation". Worth a shot as that's the only thing really sticking out at me in your scan. That throttle position value shouldn't change at all once that pedal is pushed to the floor.
 

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Discussion Starter #10
I'm wondering now if it means my TPS is going back or there is a wiring issue somewhere. I would think if the TPS was going bad it wouldn't cause a slight change in the WOT percentage like that. It almost seems like noise somehow.

Robotech, could you ask some of your HP Tuner friends if they've ever seen a fluctuating WOT percentage like this in a datalog and what it cause as well as what caused the symptoms? Maybe they would know....
 

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Robotech, could you ask some of your HP Tuner friends if they've ever seen a fluctuating WOT percentage like this in a datalog and what it cause as well as what caused the symptoms? Maybe they would know....
I can but you can too. I'd contact Dave Gilbert with PAW or Martin Scott with RPM and see if they have any insight to that. That's who I'd be asking (though technically I think they pass on those questions to their tuners. LOL) You could also ask Dave with DDM Works but he is pretty busy with the Slingshot platform or Bill Hahn Jr. but he'd busy dodging hurricanes sooooo. LOL
 

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Discussion Starter #12
I can but you can too. I'd contact Dave Gilbert with PAW or Martin Scott with RPM and see if they have any insight to that. That's who I'd be asking (though technically I think they pass on those questions to their tuners. LOL) You could also ask Dave with DDM Works but he is pretty busy with the Slingshot platform or Bill Hahn Jr. but he'd busy dodging hurricanes sooooo. LOL
I sent an email. I just figured you knew some people on the HP Forums who would be able to lend some insight. I doubt I would get as detailed an answer etc...as you would probably be able to get.
 

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I sent an email. I just figured you knew some people on the HP Forums who would be able to lend some insight. I doubt I would get as detailed an answer etc...as you would probably be able to get.
With something like this that may be specific to the Ecotec platform, doubtful. I don't operate over there very often and when I have, it's not like here. Just too many things going on to be involved like I once was.
 

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Discussion Starter #14
Well I just bought the trifecta custom tune that allows you to catalog and send in for further tuning. Maybe they will find out what's commanding that relative throttle to fluctuate.

I've heard if it was something outside of the ecu like a sensor being faulty it would typically through a code, but this never has so it's probably some part of the tune commanding the relative throttle position to fluctuate.

In any event I'm going to add the accelerator pedal position to my torque pro datalogs to see if I can see the difference there.
 
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