How do you test for a bad bypass actuator

[Tomlouns]

whipple thinks I have bad tune... my tuner thinks I have a bypass issue...

2015 mustang gt stage 2 gen 3 132 TB

How do I go about testing this?

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[JennyStang]

Put whipped tune back on if cars works fine it’s the tune

 

[Burkey]

whipple thinks I have bad tune... my tuner thinks I have a bypass issue...

2015 mustang gt stage 2 gen 3 132 TB

How do I go about testing this?

Apply 10” of vacuum to the bypass hose. It should hold for 30 seconds and you should hear the valve snap shut once you release the vac.
That’ll prove/disprove the actuator.
As to whether the bypass is sealing properly... that’s a separate issue.
Is it possible that the O-ring is installed incorrectly?
What are the symptoms?
Finally, who is your tuner? I have tunes from two different companies in my car. One of them ramps the throttle so slowly that the bypass will rarely close under normal driving, the other is brutal, can barely touch the throttle without bringing the boost on.

 

[Tomlouns]

Apply 10” of vacuum to the bypass hose. It should hold for 30 seconds and you should hear the valve snap shut once you release the vac.
That’ll prove/disprove the actuator.
As to whether the bypass is sealing properly... that’s a separate issue.
Is it possible that the O-ring is installed incorrectly?
What are the symptoms?
Finally, who is your tuner? I have tunes from two different companies in my car. One of them ramps the throttle so slowly that the bypass will rarely close under normal driving, the other is brutal, can barely touch the throttle without bringing the boost on.

PBD is my tuner... The car is running lean and has a hesitation when first start off if you try and start off quickly... It doesn't have the issue when the car is cold. I paid a shop to install the blower... I think it was installed correctly, but I guess would have to pull the blower to check that o-ring...

 

[Burkey]

PBD is my tuner... The car is running lean and has a hesitation when first start off if you try and start off quickly... It doesn't have the issue when the car is cold. I paid a shop to install the blower... I think it was installed correctly, but I guess would have to pull the blower to check that o-ring...

Not hard to pull the blower to check O-ring.
It’s been messed up often enough that Ken made a video about it.
Lean certainly implies a leak somewhere downstream of the MAF.

 

[Tomlouns]

I did pull off the TB last night and everything is all connected... and moves... the spring has a good amount of tension on it to... holding it closed.

 

[Burkey]

I did pull off the TB last night and everything is all connected... and moves... the spring has a good amount of tension on it to... holding it closed.

If the O-ring is inserted incorrectly, this could be your leak.

 

[Tomlouns]

Not hard to pull the blower to check O-ring.
It’s been messed up often enough that Ken made a video about it.
Lean certainly implies a leak somewhere downstream of the MAF.

That O-ring is in the right place... I did check that...

 

[Burkey]

That O-ring is in the right place... I did check that...

Bugger.
Smoke test?

 

[Burkey]

That O-ring is in the right place... I did check that...

Wait...are you talking about the O-ring that sits under the blower, in the bypass area or the one for the TB?

 

[Tomlouns]

Bugger.
Smoke test?

yup and it passed...

 

[Burkey]

I’d be going the full redneck version at this point. Get it hot, spray aerostart around the joins, wait for the engine to grab some revs when you hit the sweet spot

 

[Martin5.0sc]

Check your pre-load on the actuator my Whipple came from factory with no pre-load on actuator and caused all types of issues

 

[Tomlouns]

1. Okay ran the test it held for 10 seconds and I could hear it snap close when released... it passed...
2. I also tested the other way... vacuum on idle it was 20 PSI and when you hit the gas switched back... Does this look right... I think it does... please let me know your thoughts.






April 26, 2019
2015 mustang gt whipple snap close bypass test
youtu.be

 

[Tomlouns]

Check your pre-load on the actuator my Whipple came from factory with no pre-load on actuator and caused all types of issues

How is that checked?

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