Spark Compensator?

[USNA1969]

There's a solenoid located between the carb and the distributor. On one end of the solenoid, one vacuum line goes to the carb and another goes to the vacuum advance on the distributor. What, if anything, connects to the other end? It looks like a vacuum line should attach there, but the nipple is corroded and looks like nothing has been on it in years. The car is a little hard to start, but otherwise seems to run fine.

Also, I have two hoses coming from the area of the brake booster. The larger of the two hoses goes to the PCV valve, but I can't figure out where the other goes. It's natural tendency is to lie along the front of the carb and then turn back toward the passenger side of the carb. The second hose is about 1/2 the size of the PCV hose.

Thanks.

 

[LVMYVT76]

Do you have the original carb on this car? Sounds like someone replaced the carb with a different one and there is not a place to hook up the hoses?

 

[minifridge1138]

I don't know much about the 1972 or about big blocks, but I don't think there should be anything in-line between the distributor's vacuum advance and the carburetor. That should just be a vacuum line and the source should be manifold vacuum (anything below the throttle plates).

I have a filter on the vacuum line going to the brake booster. I think that vacuum line also goes to the headlights.

You should get the vacuum diagram for 1972 and see what each line is and where it should connect.

Good luck!

 

[Alan 71]

The solenoid is the Transmission Controlled Spark (TCS) solenoid.
The 2 hoses are for the Evaporative Control System (EVS). They run from the ECS carbon canister to the PVC valve and then to the base of the carburetor.
Both of these are shown in detail in the AIM.
Regards,
Alan

 

[JohnZ]

There's a solenoid located between the carb and the distributor. On one end of the solenoid, one vacuum line goes to the carb and another goes to the vacuum advance on the distributor. What, if anything, connects to the other end? It looks like a vacuum line should attach there, but the nipple is corroded and looks like nothing has been on it in years.

That's the TCS (Transmission-Controlled Spark) solenoid; it shuts off manifold vacuum to the distributor unless the car is in high gear, hasn't yet reached operating temperature, or is overheating. The empty nipple originally had a little cube of foam glued to it as a filter, as that's where it vented to atmosphere.

Your Assembly Manual will show it, as well as the other hoses you mentioned.

 

[USNA1969]

Thanks guys. I'll look around for a vacuum diagram.