Not building desired boost pressure

ecoboostsho

New member
Hey everyone.  Been awhile since I've posted. I'm having an issue with the SHO at the moment.  The car was falling on its face so I did some scanning and it isn't building enough boost...I can't typically get more then 3-6 PSI even at the top of 1st.  I checked the blow off valve seals and the lines that run to the boost controller to make sure they haven't popped off (I've got them clamped actually) and they are all fine with no cracks.  I have EPP hotpipes and looked over all the connections and didn't see anything out of the ordinary.  I've checked all the fluid levels for fun and that is fine.  I don't seem to have any excess oil in the hotpipes so I don't think I have a turbo going?  No weird noises at all to be honest.  No misfires.

The one thing I do see on the scan is that the Waste Gate Duty Cycle (WGDC) is stuck at 0% most of the time.  Once in awhile it will climb and the car definitely feels faster but most of the time it just sits at 0.  I'm not sure if the waste gate is actually physically stuck open or if something else is going on?  I thought I'd ask the experts in here for advice but I will probably be taking it to a dealer.  Car has 75K on it but did get new factory turbos around 30k or so.  TIA!
 
It could be a faulty [TCBP] Sensor located  on TOP of the intake manifold. Need to inspect and verify its not restricted and free flowing.

Need to double check the lines from that solenoid to the Front to rear actuators for cracks or leaks. 

Do you have an aftermarket intake ?
Did you happen to check for any Codes. 

BTW - Welcome back Dave. Z

[PDF BELOW]

https://drive.google.com/file/d/1Q7QaIccnJDxhi-3io3v8wDj8j5llAiip/view?usp=drivesdk
 
ZSHO said:
It could be a faulty [TCBP] Sensor located  on TOP of the intake manifold. Need to inspect and verify its not restricted and free flowing.

Need to double check the lines from that solenoid to the Front to rear actuators for cracks or leaks. 

Do you have an aftermarket intake ?
Did you happen to check for any Codes. 

BTW - Welcome back Dave. Z

[PDF BELOW]

https://drive.google.com/file/d/1Q7QaIccnJDxhi-3io3v8wDj8j5llAiip/view?usp=drivesdk

Thanks Z. I'll take a closer look at the actual sensor. I just checked all the hoses so far going to it but not all the way down to the wastegates. I do have an aftermarket intake but all appears well there (airaid).

No codes whatsoever yet.

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I was curious of your BOV are VTA! PIC of the Front & Rear line to waste-gate actuators. Z



UwreKzUh.jpg
 
ecoboostsho said:
ZSHO said:
R your BOV VTA! PIC of the line to waste-gate actuators. Z



UwreKzUh.jpg
Yes they are VTA

Sent from my Pixel 3 XL using Tapatalk
I doubt it but Silicone or rubber chair caps! I'm hoping its not the other turbo! Z


[PDF ON TURBOS]

https://docs.google.com/document/d/14Bw8eQ1WwidPxJu9sJtqp_v75886pM-dLq0I-R3qmDQ/edit?%3Cbr%20/%3Eusp=sharing#
 
ZSHO said:
ecoboostsho said:
ZSHO said:
R your BOV VTA! PIC of the line to waste-gate actuators. Z



UwreKzUh.jpg
Yes they are VTA

Sent from my Pixel 3 XL using Tapatalk
I doubt it but Silicone or rubber chair caps! I'm hoping its not the other turbo! Z


[PDF ON TURBOS]

https://docs.google.com/document/d/14Bw8eQ1WwidPxJu9sJtqp_v75886pM-dLq0I-R3qmDQ/edit?%3Cbr%20/%3Eusp=sharing#
They are silicone caps and I checked them both. Appear okay.

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The BOV orange seals do crack and make the BOV fail, so check there.  Rare that the wastegate actuator fails, esp on both turbos at the same time.  No underboost code?
 
SHOdded said:
The BOV orange seals do crack and make the BOV fail, so check there.  Rare that the wastegate actuator fails, esp on both turbos at the same time.  No underboost code?
Thanks for the response! It just popped a code...P0299 ( general under boost). I did return to stock tune, 2 bar just to see, but it's still acting the same.

I did quickly check the BoV's and didn't see any tears but may check again. Only thing is if the BOVs were torn wouldn't the Waste Gate Duty Cycle be really high? What is that actually measuring anyway? Is it a real sensor someplace? The waste gates are pressure actuated correct?  I don't get why it's stuck reading at zero....?

I did a log with the SCT and everything else looks great...just not enough boost measured by the TIP sensor.

Grrrrr....

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P0299 is typically a broken wastegate actuator (2.0) or blown seal (3.5), meaning new turbo time.  IDK if only 1 has to be broken to cause the underboost or both.  I don't know enough about the balancing act here to speculate ...  There isn't any individual control over the turbos, just a control over the overall system, that assumes the turbos are working the same and responding the same.  Probably Ford thinks it is enough to point to the probable rather than the exact culprit with the code.
 
I know you mentioned installing Hotpipes but are both Front & Rear BOV plugged in? How are the Brakes?  Z 
 
ZSHO said:
I know you mentioned installing Hotpipes but are both Front & Rear BOV plugged in? How are the Brakes?  Z
Yes both are definitely plugged in and brakes are in perfect working order.

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Gray Brick said:
I had the same issue and one of my wastegate diaphragms were torn. Replaced them both and all is good
The wastegates have replaceable diaphragms or do you mean blow off valves? Appreciate the response.

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Update...I've been logging  the car and have discovered that if I turn off the car and then turn it back on the Wastegate Duty Cycle acts normally and the car performs just fine until it hits 100% WGDC and then it goes to zero and won't budge...and the car is noticably slower.  The fact that it resets itself once seems to indicate it might not be a physical problem (ie blown wastegates) but maybe a sensor issue?  I did replace the 3 bar MAP sensor with the 2 bar and the problem persists so it can't be that.  I'm wondering if the TIP boost sensor right in front of the throttle body could be failing or causing weird results so the car is limiting boost on purpose?  That said I would have thought I'd have additional codes.

 
May be a sensor problem OR like the gear on the sunshade - missing a tooth so slippage isn't noticeable until load is put on it.  Unless you can find a loose hose, I will stick with the faulty actuator theory.  I got nothing else.  Hopefully someone more experienced can come up with something.  I would pm mrhighcaliber, he is very handson, and very likely to come up with a workable solution.
 
I am still using the stock valves... I purchased new ones from Tasca.

The way I found out was to pressurize my intake system with a compressor. (4-5 psi)
Sprayed the intake parts with soapy water and found bubbles.
 
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