VS sc V6 unstable idle issue

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immortality
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Re: VS sc V6 unstable idle issue

Post by immortality »

vlad01 wrote:if you are talking about the noise in the video, just sounds like the IAC passages whistling. They all do that, its just noticeable if you have a CAI and not a factory airbox to muffle the induction noise.
Our VX did this, I took a die grinder to the sharp edge in the IAC passage which helped, playing with the blade position to alter IAC steps eventually got rid of it.

It definitely sounded like a belt issue, spent ages replacing belts and pulleys etc to no avail :(
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Re: VS sc V6 unstable idle issue

Post by vHell83 »

immortality wrote:
vlad01 wrote:if you are talking about the noise in the video, just sounds like the IAC passages whistling. They all do that, its just noticeable if you have a CAI and not a factory airbox to muffle the induction noise.
Our VX did this, I took a die grinder to the sharp edge in the IAC passage which helped, playing with the blade position to alter IAC steps eventually got rid of it.

It definitely sounded like a belt issue, spent ages replacing belts and pulleys etc to no avail :(
The very first time my car started was with no belts, it had a squeal coming from the intake area and it had no CAI either.
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Re: VS sc V6 unstable idle issue

Post by 0081 »

vHell83 wrote:
0081 wrote:What throttle body is it running.

If its a LS style make sure you have the hoses in the right spot. It can cause it to squeal

Its an ls tb with the top coolant passages removed. Theres only one hose from the tb and its on, tight and cable tied.
Probably should have explained it a bit better.
You don't have the throttle body hose and the hose that attached after the throttle body around the wrong way.

Depending the in size of the barb that's used on the larger ubend (if you do have a larger one) you can mix them up
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Re: VS sc V6 unstable idle issue

Post by kojab »

Yes I have seen that before, feediing boost pressure into the sump makes a squeeling noise. 0081 is this what you are getting at?
0081
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Re: VS sc V6 unstable idle issue

Post by 0081 »

kojab wrote:Yes I have seen that before, feediing boost pressure into the sump makes a squeeling noise. 0081 is this what you are getting at?
It would want to pull a vac on in the sump.
But feeding boost in may have the same result I'm not too sure
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vlad01
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Re: VS sc V6 unstable idle issue

Post by vlad01 »

where does the PCV inlet connection go now that there is no connection on the TB?
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
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Re: VS sc V6 unstable idle issue

Post by 0081 »

The stock throttle body has 2 connections one before the one after the blade.
As the LS throttle only has one most people drill and tap the ubend on the flange where the throttle body bolts to or if you have an adaptor on the stock ubend you can drill and tap that
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Re: VS sc V6 unstable idle issue

Post by vlad01 »

No I meant where the one on the manifold is going? the post PCV valve is built into the M90 and is active when there is a vacuum after the TB blade and the PCV inlet on the opposite side of the manifold goes pre TB to allow fresh air into the engine, this then reverses under WOT as there is no vac to pull though that hose and instead blow by pressure reverses back out that hose and the PCV valve is inactive.

Stuff this plumbing up and you can get too much crank pressure or excessive and constant vacuum in the crank case depending on the fuck up.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
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Re: VS sc V6 unstable idle issue

Post by VX L67 Getrag »

At the moment on this car the iac is trying to force air between throttle body & adapter plate literally in gasket area so it would more than likely be making some sort of noise!
vHell83
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Re: VS sc V6 unstable idle issue

Post by vHell83 »

0081 wrote:
vHell83 wrote:
0081 wrote:What throttle body is it running.

If its a LS style make sure you have the hoses in the right spot. It can cause it to squeal

Its an ls tb with the top coolant passages removed. Theres only one hose from the tb and its on, tight and cable tied.
Probably should have explained it a bit better.
You don't have the throttle body hose and the hose that attached after the throttle body around the wrong way.

Depending the in size of the barb that's used on the larger ubend (if you do have a larger one) you can mix them up

No, nothing is mixed up. The tuner put his vac lines on a certain way all feeding off t pieces and boost tree blocked) i changed them and reverted them to stock. 1 area on the boost tree is blocked. the hose on the elblow is not in use so blocked.
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