Coupla questions about vacuum and a supposed heat shield?

[conley]

Hello. I am a newb here, but have had an 82 C10 in the family for a long time. Fell to my hands eventually, and I have been trying to get it back in running condition. Unfortunately, AZ has rather strict emissions compared to ol NM where the truck was last registered, and it's not passing. I have been trying to identify the problem and was following all the vacuum hoses along according to the emissions label diagram, and I discovered that a few of them don't exactly go where they're supposed to. For example, according to the diagram, the hose from the distributor is supposed to split and go to the efe/manifold TVS and the carb, but it only goes into the carb, just below the filter. Not sure if maybe the diagram isn't exactly correct, or if someone kinda cobbled together their own vacuum system. Aside from this, i'm missing the whole snorkel assembly from the air cleaner to the duct in the grille, including the part that the thermostatic air cleaner part that changes the amount of hot vs cold air that comes back in. So basically it's sucking hot engine air all the time.
Anyways, the truck runs rich, putting out about 2.5x the legal amount of hydrocarbons. The EFE exhaust valve works, the EGR appears to be working (it moves and makes the engine stall when manually pressed). My coolant gauge flings wildly about whenever the truck is warm and driving however, so I was thinking perhaps its the coolant temp switch?

Sorry for the novel. Anybody got any ideas?

[conley]

Also, there is a pipe coming from the top of the right side exhaust manifold (it's a 305 4bbl btw) that my Haynes guide identifies as a "heat shield" that looks suspiciously like it is supposed to go somewhere, but it is just directed up at the hood at a slight angle. Smoke comes out as the engine is warming, but that may just be burning oil, leaking from the valve covers.
It's the hole, with what appears to be foil around it. Can someone check this out?

[LONGHAIR]

For example, according to the diagram, the hose from the distributor is supposed to split and go to the efe/manifold TVS and the carb, but it only goes into the carb, just below the filter. Not sure if maybe the diagram isn't exactly correct, or if someone kinda cobbled together their own vacuum system.

The vacuum line that is supposed to go to the ThermalVacuumSwitch is "de-activating" the vacuum advance until the engine warms up. This "retarded" timing makes the engine warm-up faster and idle hotter...not necessarily where you can see it on a temperature guage, but in the combustion chamber. Just re-plumbing this (assuming that the switch works properly) should help your emissions. Your distributor (assuming that it is original) would have had the mechanical advance calibrated to work with this arrangement too. This may cause other issues when the vacuum lines are re-routed.

Also, there is a pipe coming from the top of the right side exhaust manifold (it's a 305 4bbl btw) that my Haynes guide identifies as a "heat shield" that looks suspiciously like it is supposed to go somewhere

It is....It should be a piece of tubing that is foil covered/flex. It connects/conducts heat from the exhaust manifold into the intake air duct. This also aids in warm-up and emissions. The theory behind both of these was to warm-up the engine faster, which gets the choke off faster and burns-up more of what would have been emissions.

This was the technology of the time, not great...but it, and some more tuning might get you to pass testing and get you going.