WTF is wrong with my idle? - 3SGTE

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Postby Boosted_162 » Wed Apr 22, 2009 11:03 pm

Hmmm well ive completely confused myself. I had the car idling fine, i pulled off the pipe going into the intake, put my finger over slightly, the pressure got stronger and starting hunting. The pipe goes right back to the bottom of the throttle body, the big pipe in the bottom of this picture.

Image

Is this abnormal or am i barking up completely the wrong tree? I tried looking for the valve you mentioned and couldnt see anything - not sure if im looking in the right area?

Also should mention, that i run no o2 sensor in the exhaust (ive unplugged it seeing as i have no flange). Not sure if that would affect it?
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Postby sergei » Wed Apr 22, 2009 11:16 pm

That pipe is bypass that actually "supplies" the air to the ISCV.
It should go to airbox/before turbo area.
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Postby Boosted_162 » Wed Apr 22, 2009 11:18 pm

sergei wrote:That pipe is bypass that actually "supplies" the air to the ISCV.
It should go to airbox/before turbo area.


Yip, thats how its plumbed up now. But while its hunting (idle going up and down), if i block that pipe off, the idle returns to normal... Hence why im mighty confused :lol:
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Postby fivebob » Wed Apr 22, 2009 11:20 pm

Boosted_162 wrote:Is this abnormal or am i barking up completely the wrong tree?

If it's using the PowerFC then it's normal for it to do that, you're blocking off the air supply for the ISCV and it's trying to control the idle using the ignotion timing.
I tried looking for the valve you mentioned and couldnt see anything - not sure if im looking in the right area?

It's behind and to the left (passenger's side) of the plenum, mounted close to the top of the rear firewall.
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Postby Boosted_162 » Wed Apr 22, 2009 11:24 pm

fivebob wrote:
Boosted_162 wrote:Is this abnormal or am i barking up completely the wrong tree?

If it's using the PowerFC then it's normal for it to do that, you're blocking off the air supply for the ISCV and it's trying to control the idle using the ignotion timing.
I tried looking for the valve you mentioned and couldnt see anything - not sure if im looking in the right area?

It's behind and to the left (passenger's side) of the plenum, mounted close to the top of the rear firewall.


Alright, ill take a look tomorrow! Thanks heaps for your help :)
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2008 Mazda2
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Postby fivebob » Wed Apr 22, 2009 11:24 pm

Boosted_162 wrote:Hmmm well ive completely confused myself. I had the car idling fine, i pulled off the pipe going into the intake, put my finger over slightly, the pressure got stronger and starting hunting.

Boosted_162 wrote:But while its hunting (idle going up and down), if i block that pipe off, the idle returns to normal... Hence why im mighty confused :lol:

Now I'm confused, these two statements appear to contradict each other.
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Postby Boosted_162 » Wed Apr 22, 2009 11:27 pm

fivebob wrote:
Boosted_162 wrote:Hmmm well ive completely confused myself. I had the car idling fine, i pulled off the pipe going into the intake, put my finger over slightly, the pressure got stronger and starting hunting.

Boosted_162 wrote:But while its hunting (idle going up and down), if i block that pipe off, the idle returns to normal... Hence why im mighty confused :lol:

Now I'm confused, these two statements appear to contradict each other.


Whoops, i dont know what i was trying to say in that top quote! Blocking the hose makes it idle normally. Disregard what i said in the first quote :oops:
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