My modulator holds vacuum.

I crimped a WD-40 straw with a needle nose plier, wrapped the straw in teflon tape, and stuck the straw in the vacuum supply orifice. The transmission seems to shift nicely now in all gears. I need to drive car some more to find out how well it shifts when the ATF is good and hot.

I studied the vacuum diagram, and it seems like the last mechanic who worked on the vacuum system changed the vacuum check valve to a different type and omitted 4 orafices. I think this resulted in more vacuum to the transmission and the turbo. I don't know why a mechanic would such a thing, but I do know he put a Daimler-Chrysler hose on it.