Just a guess but that sounds like the BVSV my '85/22RE has that is a coolant temperature activated vacuum switching valve that sends intake vacuum to the EGR modulator. Basically there to prevent EGR operation when the engine is cold and allow it when it heats up. Later engines used an ECU-controlled VSV to do that same function. Not real familiar with the V6 engines, so it may be something else. See what the lines connect.

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