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Not Hitting Target Boost

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My car was running fine, parked it for a few hours and now will only hit around 10psi. I've checked all the vacuum lines, exhaust manifolds, the ebcs, wastegate actuator, silicone joiners, no problems. Only things I saw was a lot of black caking inside the turbo housing and noticed that their might be a short in my obd2 port.


Attached a couple logs too.


Any insight would be much appreciated.



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Cool, that's a good actuator test. I'll assume you had a gauge on the pump and the actuator moved at the appropriate pressure.

You may want to pull the downpipe to ensure the wastegate is aligned correctly and covering the entire hole. Although from your mention of the carbon buildup, I guess you did?

Can you describe your check of the vacuum lines? Did you smoke test? Did you make sure the restrictor pill is in the right location?

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For the vacuum line test I gave them all a visual inspection, they were all replaced with silicone hoses 1yr ago. Don't have the restrictor pill anymore, was removed when I went with my ebcs. Only thing I haven't done yet is pull the downpipe and check for shaft play and inspect the actual wastegate flapper.
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I just looked at your second log *6.csv...


Two questions/comments:

1. Have you paid attention to your 'normal' WGDC at WOT? When you are around WOT in your log, I see WGDC around 50%. Do you recall if that is what you are supposed to reach?

2. I need to check on my car, but I am pretty sure that under boost and WOT, both your intake AVCS should be advancing. Mine are around 10-11 degrees IIRC (cars are stage 2). In your log, they are both zero at one point when you're still 'wotting'! Coincidentally, it has learned to pull timing right when the AVCS decreases to ~0. I would think that is strange. Unless you are tuned this way??


Keep in mind I am no tuner :spin:

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The full list of mods I've got are:

Cobb accessport w/ ia tune

Cobb intake w/box

Grimmspeed uppipe,crosspipe, intercooler, aos, crank pulley, ebcs

Invidia less downpipe, q300 exhaust


The only thing I have yet to check is the actual wastegate flapper, I've been avoiding pulling the downpipe like a plague

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