Inconsistent boost

[arrivalblue]

Having issues with power. Car is monitored by a Livewire Ts+ Gauge. When going WOT sometimes it’ll boost 8-9psi. Other times it’ll struggle boosting past 3 or 4Psi. Car is stock besides drop in air filter and BOV to atmosphere. Car is a 13 MKS EcoBoost 75k Miles. Thanks guys.


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[ajpturbo]

The 8-9 psi is ok but not 3-4...are you sure the vta ...since you have a livewire you could do some logs...id take a look at them for you....you could pm me your email and I could send you a config file and how I’d want you to log

 

[arrivalblue]

Yea I VTA’d them myself with the rubber caps. I truthfully am not sure how to even data log with it. My concern is possibly a sticking Diverter valve or maybe a bad turbo? It boosts well before it gets up to temp. Then it almost heat soaks? I’ll pm you email


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[arrivalblue]

Is boost dependent on gear in these cars?


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[SHOdded]

I would check for a) loose hoses atop the intake manifold, b) failed orange seal at the BOVs, and c) loose/cracked turbo piping particularly where clamped.

 

[arrivalblue]

Will do! I’ve briefly looked for anything obvious hadn’t seen anything but I’ll double check those. Hit 8.9psi in 2nd gear pull this morning. Only to hit 3.44 the next pull. Strange stuff


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[SHOdded]

Ueah it could be a wastegate actuator  (not usually heard of on the 3.5) or a tune problem (logical).  Datalogging will show if throttle  control is being applied properly.

 

[arrivalblue]

Yea I’ll have to log it. It’s super strange to me that it’s not more consistent. Although I’m also used to Supercharged applications where it’s not usually an issue.


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[arrivalblue]

Stupid question but when I vented to atmosphere I used the rubber caps for like walkers and stuff. Apparently it cracked allowing air to escape. Would this cause the issue?

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[SHOdded]

Yes.

 

[ZSHO]

It should be noted to avoid Bootlegged items!  Z 

https://www.mcmaster.com/#40005k35/=1doph7o

 

[arrivalblue]

Haha does anyone VTA using something better?


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[ZSHO]

Haha does anyone VTA using something better?


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Serious note Glad to hear you got her fixed pronto!  Z 

www.mcmaster.com makes some awesome Silicone/vinyl caps which work great in high heat applications.....

I believe its a 1" OD, 2" Inside Height! IIRC.

BTW Derfdog might still have some available!  Shoot him a PM.

https://www.mcmaster.com/#40005k35/=1doph7o

 

[arrivalblue]

Haha yea so far it seems it has I’ll be ordering those ones you linked I like how they don’t taper probably sit lower better. I’ll have to do some pulls to see if it’s for sure the fix. I’ll try to do some logs. Want to get everything right before I put the tune and stuff on that’s been sitting for months


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[SHOdded]

Wonder if derfdog has any left ...

 

[arrivalblue]

It seems better I need to log. When on highway and mash it only goes to around 3.44-4 still. Maybe I’m expecting too much?


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[SHOdded]

On to hose checks then

 

[RandR10]

When I swapped my new transmission in I had the opposite problem because I missed the vacuum hose that goes from the turbo plumbing to the wastegate regulator valve.  It would overboost on WOT.  Once that happened the wastegate would stop opening after that until I shut it off and started the engine again, causing the overboost condition to happen any time it was given throttle at all.  Still can't figure out how it worked with that hose missing, but it did until WOT then nothing.  Check those vacuum hoses.  This valve is attached to the right side of the intake manifold and there are I think three hoses attached to it.  They're easy to miss if you've ever had the turbo plumbing off and you cannot see one of them from the top.