Hi everyone,

I am new to this forum. I bought a 1988 Fiero Formula V6 and I noticed after I bought it that something is capped off on the manifold, I am wondering what this is, where it should be connected to, and if it is important.


Thank you

[This message has been edited by FORMULA_2D_1988 (edited 09-26-2022).]

[This message has been edited by Raydar (edited 09-26-2022).]

quote Originally posted by Raydar: That's the vacuum supply for the EGR, IIRC.

Raydar, wouldn't the line to the EGR valve be coming from the EGR solenoid? And I believe the EGR solenoid gets its vacuum from the throttle body? Having said all that, and without looking at my Formula (or googling), I don't know for sure what's supposed to be connected to that port pictured above. Maybe one of the lines that goes to the fuel vapor canister?

To the OP.... Take a look at the vacuum hose routing diagram under your rear decklid.

[This message has been edited by Patrick (edited 09-26-2022).]

That is the light green line in this diagram. I think it is used for the cruise control.

[This message has been edited by Gall757 (edited 09-26-2022).]

quote Originally posted by Gall757: That is the light green line in this diagram. I think it is used for the cruise control.

No cruise control on my Formula, yet I have a vacuum hose on that fitting. I still suspect it's for the fuel vapor canister.

[EDIT] I found a diagram which indicates that the vacuum port in question does connect to the vapor canister.

[This message has been edited by Patrick (edited 09-26-2022).]

quote Originally posted by Notorio: It is taking an incredibly circuitous route to get to the Vapor Cannister...

It does indeed!

I just finished replacing the alternator on my Formula, and I could see that yes, that is the manifold port which provides vacuum for the fuel vapor canister.

[This message has been edited by Patrick (edited 09-29-2022).]

quote Originally posted by Notorio: ...these light plastic vacuum tubes that run in between the Upper and Middle intakes have cracked or otherwise been found leaking for a number of Fiero owners.

The rubber elbows and connectors also deteriorate. While I was replacing my alternator, my arm brushed against the side of my EGR solenoid a couple of times. Sure enough, it was enough to flex and break the short rubber connector located inside the circle below. (That particular rubber connector had turned into a sticky crumbly goo.) Fortunately, I had a length of rubber hose the right diameter that I could use a short piece of for a replacement.

[This message has been edited by Patrick (edited 09-29-2022).]