According to my red Haynes the EVAP system stores vapour from the fuel tank in the charcoal filter when the engine isn't running, and burns it off through the unlet manifold at cruising speed.
It has no electrical connections and the valve works entirely by vacuum.
It was fitted on various engines from 1976 until the end of the run in 1993, including the earlier carburetted engines.
I can find no exhaustive list of why some engines got it and others didn't, but in principle any engine could have the EVAP system.
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