I see. Thanks! As I've replaced all vac lines and T's, and sprayed everything from the BBV to the BCS to the EVAP solenoid and not seen any leaks, I suspect that if there IS a vac leak causing this, it's local to cyl. 4 and is likely due to the LIM. I'll be able to do the LIM job some time around late May / early June, and I'll post back with what happens.

Thanks,
Komrad36