so you ran the vacuum line from the intake straight to the VICS solenoid?
I did that once and drove it, noticed far less lower rpm power, no change in upper. just leave the VICS controller hooked up, I've played with different configurations and the VICS controller the way it's supposed to be is the best way as you found out, the computer hates any changes to any systems and is VERY picky. also found out from real experience ha ha.
I thought VICS open at 4500? I know I feel the kick in mine a bit above 4,000. and hear it!