intake manifold 2nd venturi question

[Motorsport-SVX]

I know Im not using the correct name etc..
but the secondary flap you may call it thats inside
the intake manifold I have a question about.
What operates it ? vaccum or electronic ? from time
to time I get a bog on my car when giving it alot of
throttle, almost even like a flat spot..
I was going to check the TPS sensor voltage first
and then look into the other area.
Anyone who can shed lite on this apparatus and exactly
what it works off of etc and when, Id appreciate it.

thanks
Dayle

[Mr. Pockets]

You mean the IRIS valve? The big one that closes off the two halves of the intake?

[Motorsport-SVX]

thats the beast Im referring to

[alltrac]

Originally Posted by Motorsport-SVX

I know Im not using the correct name etc..
but the secondary flap you may call it thats inside
the intake manifold I have a question about.
What operates it ? vaccum or electronic ? from time
to time I get a bog on my car when giving it alot of
throttle, almost even like a flat spot..
I was going to check the TPS sensor voltage first
and then look into the other area.
Anyone who can shed lite on this apparatus and exactly
what it works off of etc and when, Id appreciate it.

thanks
Dayle

It is controlled by vaccum I know there is a check valve and a square black plastic box under the intake manifold.

[Motorsport-SVX]

okay, cool...
I may have to take mine off and do some more
research..
Has anyone ever had any experience with parts of this
not working properly ?
(anyone with extra pieces that control this thing)
lmk, I may buy them to try to see if it makes a diff..
thanks.

[Trevor]

Originally Posted by alltrac

It is controlled by vaccum I know there is a check valve and a square black plastic box under the intake manifold.

The valve is operated by means of manifold derived pressure, but ultimate control of this pressure, is via a solenoid valve which derives a signal from the ECU.

P.S. Check the TPS for erratic operation as well as preset voltage, particularly in full throttle area. Refer to my notes in the how too section.

[Motorsport-SVX]

Originally Posted by Trevor

The valve is operated by means of manifold derived pressure, but ultimate control of this pressure, is via a solenoid valve which derives a signal from the ECU.

P.S. Check the TPS for erratic operation as well as preset voltage, particularly in full throttle area. Refer to my notes in the how too section.

checking it out this week
thanks

[svxfiles]

Dayle, there is a one way check valve under the intake manifold, behind the alternator that can crack or fail from age or heat.
The under manifold hoses get brittle with time and heat.
Check and replace them as necessary.
http://www.subaru-svx.net/photos/use...svxfiles|24710

[Motorsport-SVX]

thanks buddy..
do you know anyone whos had problems in that area
and what the signs of it are ?

Im checking mine finally tonite or tomorrow