For six years, loyal followers of the Washington Capitals have wandered why the team shows high intensity against such teams as Montreal and Philadelphia, then short circuits against such lightweights as Detroits and Pittsburgh.

There was was no breakdown last night. If the Capitals have ever played with more drive than they displayed in herding the Pittsburgh Penguins off the Capital Centre ice by a 6-2 score, it escapes memory.

The Capitals were so high for this one that even trainer Gump Embro became involved, landing a solid right to the jaw of John Doolan, Pittsburgh equipment manager, during a dispute over a goalie's stick.

Washington scored on its eighth shot, Bengt Gustafsson converting Rolf's Edberg's pass, and at that stage, 8 1/2 minutes into the game, Pittsburgh had not managed a shot on goal.

Paul Mulvey and Edberg connected to send Washington into the final period with a 3-1 lead, then the Capitals netted three power-play goals in 71 seconds to wrap it up.

The victory, coupled with Vancouver's 5-0 triumph over Edmonton last night, put the three teams in a tie for 15th place with 66 points.

Hartford is 14th with 69 points, Detroit 18th with 63 points and Quebec 19th with 60 points. There are three positions to be filled in the NHL playoff picture with regular season play ending this weekend.

"That was one of our more completely sound first periods," said Ryan Walter, who posted his 23rd goal during the third-period Penguin penalty plague. "We worked hard, kept our heads, went up and down. A lot of things have to happen when it comes down to the end with your back to the wall."

The strangest thing that happened last night occurred when Pittsburgh goalie Greg Millen broke his stick early in the second period and threw the shaft into the stands.

Doolan reached out with a replacement and Embro grabbed hold. Then Doolan swung the stick at him and Embro landed a hard right. Millen eventually received the stick before play stopped, but Mike Gartner skated down the right wing and one-handed a pass to Mulvey in the crease. The big guy collected his 15th goal and Millen received a misconduct for throwing the broken stick over the glass.

"I was only joking when I grabbed the stick," Embro said, "Because there was nobody there to take it. But he swung it at me and said he was going to give me a shot, so I popped him."

For Mulvey, playing with a protective cover over his left skate and only minimal lacing, the 15th goal was a reason for rejoicing.

"I was talking to my mum today." Mulvey said. "She's been sick, and she wanted me to get two goals for her tonight. I could have had a few more, but I'm just glad I was able to get one for her and help us win this one."

Dale Tallon pulled Pittsburgh within 2-1 on a power play before Gustafsson dazzled the Penguins and a crowd of 15.821 by setting up Edberg for a 22nd goal that matched Gustafsson's total.

Gustafssons, from the right-wing circle, faked Penguin Paul Marshall out of the play, skated in and shot. The puck was loose in the slot and gustafsson pounced on it and shot again. This time the puck lay on the goal line and Edberg poked it the final inch.

"Rolf has a sore hand today and can't shoot, so I had to make it easy for him, " Gustafsson, laughing.

The Swedes put on another sparkling show for Arne Stromberg, the Capitals' European representative, and they had to please the folks who raised a sign that read: "The Swedish Power: Tack Sa Mycket." The last half means "Thank you so much."

The coup de grace followed a series of penalities that played three Penguins in the penalty box without a Capital sinner. The architect of this situation was referee Andy Van Hellemond, making his first appearance in a Washington game this season and obviously not a member of the "don't call a penalty with a man in the box club."

Gary McAdams had 1:47 remaining on an extra minor incurred in a scuffle with Alan Hangsleben when Van Hellemond sentenced Ron Stackhouse for slashing. Rod Schutt complained and he was bounced, too although his penalty was delayed, so the Penguins would keep the minimum four men on the ice.

After Walter connected, the Penguins remained two men short and Mike Gartner rifled in his 36th goal. Then, with only one Penguin out, Millen broke another stick and Hangsleben drilled the puck right where the stick would have been for his 12th score.

At this point, with 7:43 remaining, Washington goalie Wayne Stephenson skated off, to give backup Rollie Boutin his first playing time since an eight-minute wrapup against Hartford March 8.

It was strictly Stephenson's decision, because Coach Gary Green has no intention of messing up a good thing.

"I wish we were in a playoff spot so we could rest Wayne and give Rollie as much ice time as possible," Green said. "But with our momentum, I don't want to disturb Wayne's game plans."