which pump do I have

You might have an early 94 that had not gone electronic yet, how about a pic of it, do you have a mechanical throttle linkage that runs to the throttle pedal (move the throttle pedal and links on IP move???), if so there is your answer, DS pumps are fly by wire nothing moves unless the computer says so

That there is a mechanical IP, for your WG issue we need more pics of the engine bay, I suspect no vac at the WG actuator, you need to do WG diagnostics, one of the mechnical guys will have to weigh in on how the mechanical IP'd trucks work the WG & EGR. My 94 GM book does not cover mechanical IPs