Vacuum Line Woes

[Nidraclark]

Started piecing together the engine bay on the 79' Datsun I picked up a few weeks ago. I have got basically all the vacuum lines replaced and routed correctly but there are a few I am having trouble identifying what they are and where they go; any help would be very appreciated. 

 

As far as I can tell from the FSM the number 1 & 3 nipples are "manifold vacuum" and "vacuum switching valve for fuel cut & A.I.S. control switch" or " Carbon canister vacuum tube"

 

I do not believe it is for the carbon canister because the vacuum reference for that is tee'd into the same vacuum line as the vacuum advance.

 

As for number 2 it is either "Air inlet for A.B. valve" or "Air inlet for TCS"

 

Right now the A.B. valve is tee'd into the carbon canister vent going to the intake manifold which leaves TCS, but I am not sure what TCS is.

 

 

 

[Nidraclark]

So I concluded that port 1 will be tee'd into a manifold vacuum line, and I think 3 can be plugged(Think it was used for a California emission option).

 

So that leaves port 2 which comes up right in front of the temperature control sensor(TCS). It seams like maybe it would be for a temperature signal from the manifold instead of the air cleaner?

[lowdatsun620]

Here's mine.

 

1 is pink and goes to that brass nut T which is on the egr block. 2 is green and plugs into the port at the little arrow, which comes out of that brass block with the screws which is mounted on the carb. 3 is blue and that goes to the carbon canister. Hope that helps.

[Nidraclark]

Carbon canister here correct?

 

[lowdatsun620]

Yep. The left one with the hose (purge).

[Nidraclark]

Alright I got that all hooked up I am still lost with regards to the number 2 Hose I referenced in the original post. I don't think my carb has the port  that was pointed out, what is the component of the carb that port is going to?

[lowdatsun620]

BCDD valve, number 70,78 on this diagram, bottom left quadrant: http://www.carpartsmanual.com/datsun620/Datsun620Index/Engine(L20B)/Carburetor/tabid/2356/Default.aspx

 

in the picture I took, it's right where the little green arrow is, pointing more or less towards the camera which is right between the master cyl reservoirs.

[lowdatsun620]

Here

[Nidraclark]

Alright, my truck has a Weber which does not have the bcdd function so I will just cap that port. Everything should be in the right place now. Thanks for helping me tie up the loose ends in my engine bay.