Howdy folks,

Hoping someone can help me out here...
I have a s4tII and I'm trying to get the idle perfect like it once was.

Quite some time ago I had a problem with inconsistant idle when the air conditioning was on. Wound up doing the tb mod and removing a bunch of stuff that I shouldn't have, which made the car idle worse (no surprise).

I've since replaced the BAC - this helped immensely but now I want to reinstall the ASV as well.
I'm a bit confused on how the ASV is supposed to connect to the TMIC. The nipple? on the ASV is not round, which leads me to believe that I'm missing a part.




The FSM picture above looks just like mine with the square "bump" on the nipple.
Is the original hose "keyed" like this?
I don't have the OEM hose anymore - shall I just stick a regular hose on there, clamp it down good and hope it doesn't leak?

From what I understand, both the BAC and ASV should get metered air before it gets to the TB, but does it matter if this air comes pre or post turbo?
I think the BAC originally got fed pre-turbo air but I'm currently feeding it from one of the nipples on the IC (post turbo).

I would think that by supplying the BAC with more dense air (compressed) than was originally intended might give me undesirable effects.

Thanks in advance.

 

the ASV hose is on the intake manifold to the IC. that protuberance on the valve is where the adjusting screw went when the valves had them on the GSL-SE.

the hose makes kind of a ? shape IIRC.

the Mazda part number is N332-13-752A (for an S4) $8.54 list price, Mazda has 8, but its NLA, so once those are gone, that's it

 

Replacing the O rings on the fuel diffusers (under the injectors) had an amazing effect on stabilizing my idle, especially when running my AC on my S4 TurboVert. Apparently the old hardened ones were causing a level of vacumm leak.

 

this too, those things get very crunchy after a quarter century

 

"I would think that by supplying the BAC with more dense air (compressed) than was originally intended might give me undesirable effects."
No worries. Stock it's fed post turbo. However, once off idle conditions, it's not running; it's not bypassing any air anyway.

 

Thanks for everyone's help.
It was a pretty silly question I suppose since the oddly shaped "nipple" is sealed anyway.
Gonna call my local dealership tomorrow and order one or two for sure. How can you check the availability of a mazda part? Is this something that I could do on my own without calling a dealer?
I actually did find the original question mark shaped hose but sadly it fell apart as soon as I got it connected. 8 bucks is cheaper than the L shaped hose I just bought from AutoZone.

Good advice - I think I still have some spare injector hardware and will replace these when I put on the new injector connectors which have been sitting on the shelf for years.

Is your setup using the stock BAC hose? I'd love to see a photo of it in stock form. I prolly will buy a new stock BAC hose as well - mine looks pretty ghetto.

 

You can see it in a few places in the FSM diagram.

Mine is not stock; I run a separate hose with it's own little filter because of my standalone setup.

 

Last time I looked at a series FOUR........the air supply valve only opens during use of the powersteering and when doing HOT starts. I don't see it being used during IDLE unless your steering at the same time with POWER STEERING installed on the car. Page 50-25 of the series four wiring diagrams.

BAC gets its air source from the turbo outlet duct. Series four.

 

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