Evidently, Volvo introduced Pulsair system on the US '94, '95 B230FD engines. (Explains why I couldn't find it in the FAQ.) I called an independent to check on the price of the valve ($53) and quizzed them on the formal name, which is Pulsair. They have a VADIS CD and is giving me the parts sheet for the components. Since it was used only in the '94-'95 B230FD engines, it negated my visit to a salvage year.

I do not have the Volvo emissions diagram but plan on getting it. I hope it will have the vacuum diagrams too.

My search on in the internet revealed a little. Basically pulsed secondary air injection system adds oxygen to the manifold to continue the combustion of unburned fuel in the exhaust system and provides additional oxygen for the catalytic converter, thereby lowering harmful emissions. The PAIR valve, (Pulsair valve), with permission from the ECU, allows oxygen in every time the exhaust valve closes, which causes an instance of negative pressure (the pulse) and introduces oxygen into the manifold. No air pump required.

The photo shows the two Pulsar valves feeding the manifold and a vacuum control valve which get it's a signal from the PAIR solenoid to allow air from the air cleaner box to pass through.
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Tom F Four 940s, RIP '78 244