were connecting my harness up on my engine, and we noticed on the jspec UIM that i got, there is no place for the BAC ??

my old aspec s4 uim has it but not this ...

do we need the BAC at all.. is it needed ??

if i dont have it will it affect anything else?
will this cause my check engine light to come on if we dont plug it in?

also we are trying to figure out the way the harness is routed stock ...

the front part of the harness with the injectors pretty much is laying on the actual engine ... and from what we can tell the harness then curves around to the front right of the engine, and then along the right side fender wall (passenger side) is this correct?

please help
=-dustin

 

anyone.. please?

 

my j-spec has a BAC valve on its UIM.

 

It's not in the same place as a series4, it's under the fuel rail on the passanger side, or it should be at least. You can run without one, it's just a bit harder to set your idle as it won't be able to adjust if it's too low. Also, if you have high loads (AC/etc) it could possibly cause stalling. I've been running without one for 3 years on 2 of my cars without a problem.

 

well .. then how come mine doesnt?
hmmm


do i REALLY need the bac?

 

I'm stealing one of Icemark's images here, but if you look at the intake manifold you'll see the shiney hole in the center of the two intake runners, that's where it should be.

 

my UIM doesnt look anythign like that .. mine looks like the stock TII ... just minus the BAC

i was just thinking though ... is there a direct hole into the UIM or does the BAC just bolt up to it .. cause there is a place for two bolts, but i just assumed that there was actually a hole into the manifold ...
now that i think about it though, it would make much since to have a hole from the BAC into the actual manifold huh?

or am i way off base?

 

Wow you guys are talking apples and oranges.

- SonicRat: that pic is of the S5 N/A manifolds.

- Fitness Stain: yes the J-spec does have the BAC it's in the same place as the US-Spec one. Look at this picture of a S4 J-Spec engine http://www.stormperformance.net/images/13BT_S5T.JPG the BAC is on the upper intake manifold on the left side, look where the loose plugs are right next to those you can see the BAC with the blue end on it. S5's have them in the same location.

- Dana

 

Yikes, I'm definatly not paying attention! Wasn't even paying attention that it was a jspec manifold, which means turbo. ahh, I definatly need sleep, sorry about that

 

lol

 

Yes the Jspecs have a BAC.

If you look in that pic it is on the left side newar the yellow ECU plugs.

It should be on the passenger side of the manifold centered and about 2 inches from the LIM . There are 2 holes for the BAC.

they are the size of a Pen and go to the two middle runners.

I can only think that the previous owner welded it shut or something.

Take a pic if you can and we'll be able to help more.

 

so there are actual holes for the bac directly into the manifold?

theres the holes for the bolts or whatever, but not actuall holes to go into the manifold for anything else other than the bolts

 

Here's a more relevant picture of my s5 tII jspec manifold. there should be two studs there, but if they're removed it would leave two bolt holes, unless someone JB welded over it and smoothed it out.

 

cool ... thats exactly what i needed to know..

thanks man

 

All 13BT's have the BAC valve in the same place. You're not talking about the ASW valve (above the BAC valve) are you? J-specs don't have those. If not, the mounting point must've been cut off, welded over and ground smooth like SonicRat suggested.

 

i think thas actually what the case is ... it looks like its been welded or patched (its kinda sloppy looking)

doesnt really look stock but you never know ..

any way . thanks for the replies