HoustonMS3

I found some cracks in the base of my TIP, so I am probably just going to make one out of some couplers and angled intake piping.

My questions is: What is the purpose of this check valve that I have the red arrows pointing to, air filter load? Can I reroute it or do I have to put a fitting int he intake pipe?

I know the other one is a blow by return and i should be able to put a catch can on it.

1990 TII
<a href="http://s222.photobucket.com/albums/dd66/crackattak/?action=view&amp;current=VacuumDiagramcopy.jpg" target="_blank"><img src="http://i222.photobucket.com/albums/dd66/crackattak/VacuumDiagramcopy.jpg" border="0" alt="Photobucket"></a>

I know the picture is huge, but I bet it will help some in the future...

HoustonMS3

Woops, misread the diagram. I guess that check valve is the one way on the pcv like line.

So I guess when it is not pressurized it pulls the contents of the charcoal canister?

AGreen

iTrader: (11)

Yes and no. See, it's BEFORE the compressor, so it's never really pressurized. It will undergo some kind of vacuum at one point, so it does suck the charcoal canister and crankcase blowby in through the turbo. The "other one" I think you're referring to is the air bypass valve. Not for blowby return, it's to prevent compressor surge, and is quite necessary. If you're going to make a new TID, you should make it so that it vents to the same place.

Search "catch can" and you'll find a lot of info on it if you don't want to route that little check valve back to the inlet duct.

HoustonMS3

Nah, i know what BPV return is, I just read the diagram hastily bu


There are three hoses going in the turbo inlet duct.

1) BPV recirculation

2) One going from the filller neck where it seems like the charcoal canister fumes and the excess oil being pressurized in the fill neck goes.

3) The boost duty solenoid? Where can this be rerouted?


Thhanks.

AGreen

iTrader: (11)

The S5 wastegate spring is only 5 psi. That line is only a return to the TID from the duty soleniod. What happens is the duty solenoid will bleed a little pressure off that line, preventing the wastegate from opening too soon, allowing the boost pressure to reach 7.5 psi and not just 5. If you go back to the duty solenoid and remove that line completely, it'll be fine. It's only routed back to the TID to prevent an air noise. No, not the pssh like a VTA blowoff valve, but a small air bleed noise under boost as it bleeds off. If you can live with it, remove it.

Just don't bypass the valve. You'll lose power.

HoustonMS3

Exactly what I needed to know, thanks!