Ben951S

See pics. Found near where the Crank and Reference sensor wiring is. By the way, I think mine is getting brittle [sensors are new as of 2008 IIRC]. Going to look into that...

But anyway, found this piece of vacuum 'hanging out' in the car. I had some work done by a good shop, wonder if they caused it, or somehow didn't notice. I DID notice my vacuum at idle is a lot lower (~10 in mg), but under load it is very good (20). They did replace my torn Jboot, but my idle vacuum is 'low' compared to before.

Scott H

That is the vacuum check valve, depends on the year where it goes, but it's meant to keep the vacuum in the vacuum canister for the A/C to function correctly when the engine is not making a vacuum.

Ben951S

I just had the AC serviced and it's been fine for 2+ weeks. Could I be causing damage running the AC? I will see if I can reinstall it before bring it back to them if I cannot.

89 Turbo (S). Should be in my sig. Weird will fix. Thanks Scott H.

Also was poking around and found

http://www.lindseyracing.com/LR/Parts/VACDIA.html

and you can see it lays right where I found it...

JohnKoaWood

There should be a T union on the line leading to the brake booster, with a small nipple on it that connects to the black side of the check valve, then the check valve leads to the vacuum reservoir, with a T running down to the firewall nipple, with the other firewall nipple connected to the heater control valve.

Ben951S

So it looks like it just pulled out then? I do have a Lindsey vacuum kit I haven't installed yet, might be a good reason to start exploring. JKW, can I access all of those things without tearing into it too much?

This looks like the correct installation point, correct? (borrowed pic)

JohnKoaWood

Yes... sort of..

The white piece on the right hand side.. it shouldnt have a t running to the fuel vapor purge actuator (t below the white plastic piece... the white plastic junction should only be routed to the check valve..)..

Other than that, yes the picture is correct, and although it doesn't really matter how the lines are routed, the vapor purge system should be connected to the thermal valve on top of the coolant elbow coming off the head.. but thats another discussion all together!

I have seen MANY MANY butchered vacuum line routings... and many many cars with poor vacuum at idle... the correct line routing seems to me to work the best!

Ben951S

Thanks JKW. That's a borrowed picture from the internet, not mine. I will see if I can restore the piece I found today in the original post. You don't happen to be on the East Coast, do you?

JohnKoaWood

Stafford VA.. my avatar was taken on RT5 in MD.. when we headded out for this years Fest in OH.

Ben951S

So I couldn't get air through that thing either way, and neither could the tech I worked with. A new check valve is $25 (was quoted). However, hooking it up to a hand vacuum it functioned correctly, so we reinstalled it, and it seems to be okay. Will keep an eye on it. I believe it is working because I get exhaust smell in the cabin under load on recirc, which if I remember correctly I used to get. Hatch seal or taillight seals maybe? Will research.

JohnKoaWood

More than likely hatch seal.. I have some aftermarket seal that works great if you need it...