The Washington Diplomats, who began the season promisingly with a 7-1 record, face the possibility of dropping below 500 Wednesday night when they meet the New England Teamen in Foxboro, Mass.

The Vancouver Whitecaps handed Washington its six consecutive loss, 2-1, Saturday night at RFK Stadium, evening the Dips' record at 8-8. The setback, witnessed by 10,615 disheartened fans, was decided by tie-breaking one-on-one kicks.

Mike Bakic's goal gave the Diplomats a 1-0 first-period advantage. A five-yard header by Vancouver's John Craven sent the game into overtime.

In the shootout that followed the scoreless overtime, Vancouver's first two shooters, Bob Lenarduzzi and Steve Kember, scored against Dip goalie Bill Irwin. Washington's second shooter, Tommy O'Hara, tallied against Vancouver goalie Phil Parks.

The next three shooters for both teams missed, leaving Vancouver with a 2-1 kick advantage and the match.

New England, with a 1-0 victory yesterday over Toronto, moved into first place in the American Conference Eastern Division, Following the Tea Men contest, the Diplomats visit the Cosmos in East Rutherford, NJ., on Sunday before playing at home June 20 against the Los Angeles Aztecs.