Hi all, a total newbie here... first a couple of background facts... i drive a 97 z28 with a vortech supercharger.

I noticed a couple months ago that my boost gauge read less vacuum than usual, it concerned me and i looked around the intake for leaks but found none... Today, i noticed a 'whooshing' sound from under the hood and investigated to find that the small valve or t-connector behind the two ac lines on the passenger side to be broken. Looks like there were three lines that came together at this point, one of them probably leads to the intake as it sucks in air while the car is on. I plugged this temporarily and my vacuum reading is normal, but no mechanic knows what the part was or where to get a replacement.

Couple of questions for you all, does anyone know what this part is and what the tubes leading to it function as? Is plugging it ok for now? Someone suggested these lead to the heater?

Also did having this leak for a couple months do anything 'bad' to my engine? I didnt drive the car hard or anything lately, no boost use practically. Would this kind of leak affect a/f ratios or anything like that?

Thank you all for your help!!!!

 

Trace back the other 2 vacuum lines (not the one to the intake) and let us know what they connect to. My guess is that they connect to your HVAC check valve and you know longer have your vents working properly in the interior. Here's a photo of the check valve from Shoebox's site:

http://shbox.com/1/vac_check_valve.jpg

 

yes... thank you SO much for this.... this is exactly it.... and yes you are right my vents have not worked for a LONG time, the valve must have been broken for a while and a couple of months ago it must have totally fallen apart as i noticed the vacuum reading on my boost gauge change... other than the non-working vents, any risks in driving the car with the pipe plugged as i have it now? also could i have done any damage while i drove it unplugged for a couple months before i noticed what it was?

thanks so much for this and the part number in the image this is great!!!!

here is a pic of it i just took:

 

No risk with the other 2 lines not connected. One leads to your HVAC controls in the interior, the other leads to a vacuum tank under the passanger side head lamp. Both of these functions are to allow you to run your vents properly. The check valve is around $6 from the dealership; may also be available for the local auto parts store.