One of them is the bov. What is the other. I already have the DIY BOV, and i have a 3" pipe for my TID mod. What is that other line called. and can i just cap it off. It's kinda down below the accordion bend.

 

bump*

 

Goes to the BAC.

Jarrett

 

do i need to mount it in my new pipe, or can i just cap that sucker off?

 

do you still have a bac?

 

Slow down there, J-rat .

The other small line has a metal check valve - that's the PCV valve. The BAC plumbs in to the metal pipe coming out of the turbo going to the intercooler.

I *think* that connection is just to the PCV system, in which case you can leave it open-air vented - it won't cause a vacuum leak. Might have a little oil mess coming from it, however.

Dale

 

Okay, I dont know what TII you have Dale, but there are 2 lines coming off that section of pipe. One for the BOV, and the other that runs to the BAC.

What are you talking about?

 

J-rat, you're wrong .

On the '87-88 TII's, there are two lines plumbed into the inlet duct - one is the CBV (stock blow-off valve, Compressor Bypass Valve) and the other is a small aluminum one-way check valve from the PCV (Positive Crankcase Ventilation) system. This expels crankcase vapors into the inlet duct - by emissions law, any emissions (including evaporative) have to be burned and go through the cat. That's why it's plumbed into the intake.

On the '89-91 TII's, there are 3 hookups on the inlet duct - the CBV, PCV, and a vaccum line going to the stock boost control solenoid. The BCS vents wastegate pressure to the turbo's inlet, which is always at vacuum.

The BAC (bypass air control valve) is on the upper intake manifold. There is a pipe going from the turbo's outlet to the 90 degree elbow into the stock intercooler that has a nipple - from there, a short piece of rubber hose feeds the BAC. This is true on all TII's.

You may be confusing the turbo *outlet* pipe with the turbo *inlet* pipe - the outlet pipe has the stock BOV and the BAC line on it. The turbo *inlet* is the goofy rubber contraption going from the turbo inlet to the stock airbox.

Dale

 

*edit*


Okay, now I see. He is talking about the inlet for the BOV to recirculate. Okay, my bad, I was the one confused.

and FYI, I drilled a hole, and installed a nipple for that vac line on my TID mod. Looks cleaner then an open vac line hanging around.

 

That's all good. Of course, now I've probably confused the original poster with a litany of 3-letter acronyms .

Dale

 

Yes, I know my engine bay is filthy.