In regards to the response about removing emissions controls, I generally agree they should not be removed. I never advocate removing emissions hardware from fuel injection cars as they do tend to have a positive effect on reducing emissions and have little or no effect on drivability.
These parts from that time period don't really fulfill any of those things, particularly nearly forty years on.
As I didn't explain what they are and what they do previously, I will now. They are electrovalves that use switches on the transmission and the clutch pedal to effect idle in certain running conditions. There is also an additional switch in the circuit which is used to test the system for proper function and to set up the system to work properly. To properly adjust the system you do need access to a CO meter.
One if them holds the throttle open and closes the choke plate on the primary throat of the carburetor to keep rpm up during up and down shifts between 3rd, 4th and 5th gears. It will hold the rpm during those shifts at 1600 rpm while the clutch pedal is actuated and you are shifting between the gears. (there is a switch on the pedal and on the transmission to sense when these things are happening).
To test whether the system is working properly warm up the car and then with the car revving at or about 2500rpm, press and hold the the test button down on the fender wall next to the electrovalves and then let the rpm drop. If the system is working properly it will drop to 1600 rpm. When you release the test button the rpm should drop to your normal idle speed in 1-3 seconds.
Personally I have always hated the various solutions to reduce NOx emissions that hold the throttle open which has ranged from this semi complicated solution to simple dashpots all make driving these cars less enjoyable.
If the system is not working, I would plug the vacuum connections on the manifold and carburetor side to isolate the electrovalves.
The other controls the EGR system which I would bet has a frozen solid EGR valve which no amount of vacuum will ever open again.
All of the manuals I have show hose layouts for these parts so I would suggest picking up a Haynes, Clymer or a factory manual to reference for these sorts of questions. They are cheap and generally do not suffer from having opinons like most of us do.
