I found something at the Volvo Owners Club site (of the U.K.). Two references to a B230FD.

First, "... 1994/1995 940 B230FD non-turbo cars using either Bosch or Regina have rather square, squat, blue-colored fuel injection relays in the front row, second from right...."

And second, "...Volvo introduced Pulsair system on B200/30A, E, and K-engines and on the US '94-'95 B230FD engines. The Pulsed Secondary Air injection system adds oxygen to the exhaust manifold to continue the combustion of unburned fuel in the exhaust system and provides additional oxygen for the catalytic converter, thereby lowering harmful emissions. It is independent of the EGR system and many cars have both. The pulsed secondary air injection solenoid or PAIR Solenoid, receives a signal from the ECU allowing the vacuum control valve to open. It is located on the left strut support between the EGR Converter and the OBD box. 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 exhaust manifold and a vacuum control valve which get its a signal from the PAIR solenoid to allow air from the air cleaner box to pass through. If a valve fails, it can allow exhaust gas flow back, cooking the rubber hose. The hose is connected to a vacuum operated shutoff valve connected to the air cleaner. To test the pulsair valve, on a cold engine, place your hand over the valves, near enough to verify that air is being taken in and exhaust gas is not escaping. The action of the valve is a quick pulse corresponding to the opening and closing of the exhaust valves...."

Hope this helps, a little bit anyway.