bigti99a

iTrader: (16)

ok on my way in to work today i go to hit the a/c. i hear the fan blowing and dont feel anything coming from any of the vents. there is cold air flowing b/c i feel it at my feet and at the defroster. i turned on the warm air and the same thing.
the derfroster and feet vents work fine. it is the 4 dash vents that are not working. anyone ever heard of this? could there be something jamming teh vent system?
HELP!

2001NBMZ28

Blowing only at your feet/defroster is the default setting - you've got a vacuum leak. Check for a loose, cracked or disconnected vacuum line behind the intake and going towards the passenger side.

bigti99a

iTrader: (16)

ok i will check when i get home. i did degrease the engine with simple green last weekend. no problems noticed other than this. can they be related?

bigti99a

iTrader: (16)

alright i check real good for any cracked hoses this morn. i did not see any so i fired the car up and turned on the dash vents. still nothing, not that i expected it to magically fix itself. but i felt around both sides and behind the intake manifold to see if i could feel anything. there is a valve on the air system on the drives side that was putting out some air then stopped. i doubt the air system has anything to do with this issue.
can somebody help narrow my search for a leak or other cause to this? HELP!! i need to get all the BS things taken care of before summer gets in full swing!

zaner

iTrader: (16)

To the right of your pcm is a black check valve canister that has 2 or 3 vacuum lines coming off of it. Id say the valve is no bigger than 1 1/2" x 3/4". Mine randonly started doing the same symptoms of yours and thats where I found the vacuum leak at.........

bigti99a

iTrader: (16)

should i run the car while i am checking it? will spraying any soapy water help show it as well? and am i hurting anything by driving it? thanks for your help.

bigti99a

iTrader: (16)

ok i checked there and have found a very tough plastic line has be shredded. i cant seem to fine the other end. on that valve there is one line on one end and two on the other. the problem line is the straight line off the side with 2 lines on it. it looks like the run into the wire protectors around the pcm. can anyone tell me where this line is supposed to go so i can find the other end. and to i just need to find a way to join the 2 or should the whole thing be replaced?
....and a million thanks to everyone that has ever helped me on this board. i am a car lover but not a guru mechanic. Zaner your input has saved me tons of time!!

Phoenix 5.7

iTrader: (7)

if i had to guess, its the tiny black hard plastic line that goes to the back passenger side of ur intake manifold. i had mine come off and it did the same thing, and that line feeds the vacume for that little black valve thing

1sick'98WS6

iTrader: (19)

Correct, it goes into a little rubber sleeve right by the map sensor

bigti99a

iTrader: (16)

will driving like this hurt anything until i put my ls6 intake on in the next week or so? and where do i get a replacement line, or coupler?

2001NBMZ28

Won't hurt to drive it, parts are probably a dealer item.

my2kTA

iTrader: (7)

just wanted to say that I found this thread while trying to figure out why my top vents werent blowing since I had the engine built up. This was very helpful as i checked the little valve and followed one of the lines to an emty connection. i had the GF check the back of the intake since she has small hands and viola...1 minute later i had cold air blowing out of the vents again

this was the only thing keeping me from driving my car as much as id like and i was getting ready to take it to an AC specialist :X

Mr. Trick

iTrader: (19)

I'm having the same issue right now. I havent checked behind the intake, but the plastic line that goes in the wire loom was disconnected. It looks like it goes around to the driver side, what is it supposed to be connected to?

my2kTA

iTrader: (7)

If i am thinking straight, this is the same one that I had disconnected.

The little valve has 3 connections. On mine the top connection runs down to the horn (pass headlight area) the bottom one goes to the back of the intake (towards the driver side) and the back one seems like it heads back to the firewall.

t/afrom504

what size is that line that goes to the firewall anyway? when i checked the line at the firewall, i felt a hole in it...

HoLLo

iTrader: (17)

I had a similar problem before, the air only blew on my feet. I had been messing with the harness behind my radio and accidentally had pulled out this little harness with a couple vacuum lines attached to it that ran to the HVAC control *****. I plugged them back into the HVAC controls and I had working air vents. You could hear a vacuum leak inside the car (almost sounded like radio static though) when the vacuum was unhooked. It was very tight trying to plug the harness back in, but it went. Try that out.

JScamaro

iTrader: (6)

I had this same problem when I removed my AIR equipment. I acidentally pulled out that tiny vacuum line behind the intake.

You could hear the AC blowing but nothing coming out of the vents. I would say the line felt even smaller than a straw since I couldn't really see back there.

I had to go one day in the Texas heat without AC and it definitely sucked.

yeller_xtc

iTrader: (7)

pull the **** off your selector switch make sure it isnt broke. thats what was wrong with mine...if thats the case ill send you a spare ****..

spdrcr7882

I had the same problem, found the black hose that goes to the back of the manifold, sure enough it was disconnected. I hooked it back up and sure enough, now my vents work for my a/c.
thanks for everyone's help.
justin

cnw8891

iTrader: (3)

Does anybody have a part number for that check valve? My junk broke and this Georgia heat is a force to be reckoned with.