luvchevs

My 94 coupe is not blowing cold air out the dash vents.
Base on suggestions from forum members I looked at the check valve that is located on the passenger side of the intake manifold.
I replaced it although the original appears to work. I get vacuum past the check valve.
Went to the vacuum programmer under the dash and don't appear to have vacuum there. The line is almost impossible to follow it runs along the firewall and is buried in wire looms. When we blow compressed air in the vacuum line past the check valve when can feel it come out the connecter that goes into the programmer. This makes us think there isn't an issue with the line?
Why is the vacuum disappearing?
The line that goes into the programmer seems more flexible than the line coming off the check valve, is there a connection somewhere between the check valve and the programmer?
Anyone have a vacuum diagram that might help?

Dave

rodj

If the LT1 is plumbed the same as a L98 ;
downside of the valve is a T (L98 valve is a T as well as check valve ) that supplies vac to the cruise control and the line ultimately ends up at the vac storage ball under the drv side headlight