ZDC CTLR LOST SEPARATION BTWN 2 SMA ACFT MANEUVERING FOR AN IFR APCH TO PGV.

Narrative

ACFT X (C414) AT 4000 FT INBOUND TO PGV FROM ISO. ACFT Y (BE20) DSNDING TO 5000 FT INBOUND TO PGV FROM THE S. THE WX WAS IMC; BUT I DID NOT HAVE THE WX OR AN ALTIMETER AVAILABLE TO ME AT THE SECTOR. IT HAD BEEN OTS OFF AND ON FOR WKS. I HAD TO ASK THE ARRIVING PLTS IF THEY HAD THE WX INFO BEFORE CLRING THEM FOR APCH. I CLRED ACFT X FOR THE ILS 20 APCH TO PGV AND ASKED HIM TO RPT OUT OF 4000 FT. ACFT Y WAS CLRED TO AQE NDB TO HOLD. I WAS WORKING THE RADAR AND RADAR ASSOCIATE POS COMBINED. ACFT X WAS A MANUAL HDOF FROM GSB APCH; SO AFTER CANCELING AN OLD FLT PLAN AND ACTIVATING THE NEW AND POSTING THE STRIP; I NOTICED ACFT X HDG NW AWAY FROM THE ARPT WHEN HE RPTED LEAVING 4000 FT. I ASKED ACFT X TO SAY HDG. HE SAID 'LOC OUTBOUND.' I ADVISED ACFT X THAT THE LOC/NDB WAS 6 NM E OF HIS LOCATION. I TOLD ACFT X TO CLB TO 4000 FT. ACFT X WAS HDG NW. ACFT Y WAS THEN E OF ACFT X AT 5000 FT PASSING APPROX 6 NM. I THEN CLRED ACFT Y TO 3000 FT TO REVERSE THE SEQUENCE AND PREVENT ACFT Y HAVING TO HOLD IMC. ACFT X SAID HE WOULD COME AROUND AND SEE WHAT WENT WRONG. A MIN LATER; I NOTICED ACFT X I A R TURN EBOUND TOWARD ACFT Y. I ASSIGNED ACFT X A 360 DEG HDG AND CALLED TFC TO ACFT Y (HE WAS IMC). I EXPECTED ACFT X TO CONTINUE HIS NW HDG WHILE CLBING TO 4000 FT. HE DID NOT.