Good day folks. I am working on my 92 RS that I just bought. The valve covers and air cleaner looked like hell so I took them off, blasted and painted them. Now I have a dilemma. There were two plastic lines that were brittle and broke in the process. One goes from the intake into a conduit on the firewall the other one broke off and I can’t even see where it came from. I put new rubber hoses on everything that came from the TBI but I still have these lines outstanding. The one that broke off ran right next to the valve cover. What are these lines for? The HVAC works ok so I am concerned that it’s maybe cruise control? Car is in the garage for the winter so it’s tough to test it.

 

https://www.thirdgen.org/forums/tech...ol-vacuum.html

 

All the emission stuff is hooked up and correct. The photo shows the harness that the line comes out of right behind the tranny dip stick

 

Could there be a missing t that ties manifold vacuum between hvac and cruise ?
Or is it missing coming from hvac to the heater control valve.

 

That’s the line that broke off next to the valve cover. I can’t see where it originated from.

 

Just tested the HVAC and it functions normally so all I can think of is cruise. If it jack the rear of the car and put it in gear is it possible to test the cruise?

 

Yes, I’m not that brave

 

You could allways run the car and check for vacuum at the ball.

 

Ya me either but it’s not plated so I can’t drive it. There must be someone on here with the same engine that could grab me a picture on that side of their motor. I can’t use my TPI car for a template as it’s totally different. In this picture is there supposed to be a vacuum line coming off this thing?

 

Answered my own question

 

That looks like the heater control valve. Yes there is hvac vacuum when heat is requested via the dash switch.

 

That was covered in Post #4 lol

 

And done!!!

 

Great news

 

Yeah, if that vacuum line was not connected you would create a leak which would cause the HVAC head unit to default to having only defrost as an outlet vent choice no matter where you tried to set it. Good catch!

 

i hate vacuum HVAC. lol ford used them in the crown vics up until like 2004 i believe

 

Kent,, can you tell me where the lines go to black box on right. i would really even pay you for your time. i have a 92 and im putting it together/ I dont even know what it is called. i wait for your email.

 

Go back up to post #2 and look at the diagrams