Just a quick question on diagnosing a bad pump.....
Is the power loss experienced as extensive as is if you unplug the SC clutch electrical connection? When I did this and took it for a test spin the engine power was much less than just a N/A 6 cylinder. It ran, smooth idle and without missing, but it was WEAK.
Something curious did happened after I reconnected the SC clutch. When I took it for another test spin, to make sure the SC was back in service, upon the first hard acceleration from a stand still it would NOT stop spinning the tires ( I think that when it shifted into second the tires kept spinning). The power seemed better than ever but maybe it was just a fluke. I never tried to re-create the scenario.