Mine did this on saturday after rebuilding / reassembling a B16. Just to see what was up I opened up the Vtec solnoid on my Z6 and compared the 2
The plunger on the B16 unit pumped oil fine, but when I compared the 2 I found that on the B16 the little round slug sat flush with the case.
On the D series (working) Unit , it sat slightly above.
Cleaned it with brake clean..worked the plunger and it sat above the case like the other one... bolted it up and it works great.
Screen was clean when I pulled it apart , I even cleaned it with brake clean and air the first time around, but I imagine some particles were in there from when the OG motor blew a bearing.