For months, diehard political junkies in Northern Virginia's 10th Congressional District have eagerly awaited the debates between Republican Rep. Frank Wolf and his Democratic challenger Ira M. Lechner.

Would Wolf repeat the sort of feisty verbal assaults that left former Democratic representative Joseph L. Fisher complaining Wolf was "yapping at my heels?"

Would Lechner display the verbal vitriol that has earned him the enmity of some who resent his often-sharp tongue?

Not if last week's debate before the Arlington Civic Federation was any indication. Those who gathered in the stuffy cafeteria of Arlington's Woodlawn Hills Apartments expecting political fireworks got little more than a sparkler.

Wolf, a 43-year-old former lawyer-lobbyist from Vienna, and Lechner, a 48-year-old labor lawyer and former delegate from Arlington, quickly staked out predictable positions on issues ranging from the 1983 federal tax cut (Wolf favors it, Lechner doesn't) to National Airport (Wolf says he has worked to reduce use of National; Lechner says Wolf hasn't).

There was a third candidate on the platform last week, Libertarian Scott Bowden, a 28-year-old data processing consultant from Falls Church, who says he is running as a symbolic protest against government control and the major parties. At last week's debate, Bowden, a sober-faced man with a bushy brown beard, earned approving applause from the audience, nearly all white and most over 40, when he called for the abolition of taxes.

The candidates from the two major parties rarely got that kind of response.

Officials from both Wolf's and Lechner's campaigns later attributed the lack of political pyrotechnics to the fact that it was one of the candidates' first joint appearances.

"I think probably both of these candidates are trying to see what the other was going to do," said Wolf campaign manager Tom Moor, who predicted future debates would "warm up."

"They were both on their good behavior," said Lechner's press secretary, George Randels. "They were feeling each other out."

The high point of the evening was provided not by the candidates, who sat in wooden chairs looking glum and uncomfortable, but by gadfly journalist Lester Kinsolving, who lives in Vienna and says he voted for Wolf two years ago.

Kinsolving, a longtime member of the Washington press corps, is widely known for asking prickly questions of the sort that once caused former State Department spokesman Hodding Carter III to fling a rubber chicken at him.

While many in last week's audience barely suppressed yawns, Kinsolving seemed fascinated. He pointed his portable tape recorder at the candidates, took copious notes and waved his hand wildly as the moderator asked for questions from the audience.

Kinsolving castigated Wolf for not taking to the House floor and calling for the resignation of former New York Rep. Fred Richmond, who recently resigned from Congress after pleading guilty to tax and drug charges. Although Kinsolving did not mention Richmond by name, he later told a reporter he was referring to Richmond.

As the astonished audience stirred and tittered expectantly, Wolf strode to the platform. "We referred that to the House Ethics Committee and the committee was acting. . . . The congressman on his own left the House. I'm glad he left the House," Wolf said. "He did the right thing by leaving. If you're ever in that situation I think anybody ought to leave the House or leave whatever they're doing."

Kinsolving then asked Lechner if he thought "the House office building lavatories and Iwo Jima Memorial should be free of congressional sodomists or not?"

When Lechner said he thought he would let "someone else answer that one" Kinsolving protested, saying he was considering voting for him. Lechner then replied, "It's quite obvious that the laws of the United States and the laws of whatever jurisdiction should be applied equally."

Although Kinsolving's questions were the highlight of an otherwise lackluster debate, it is doubtful that either candidate's views on congressional peccadillos will sway as many votes as what they have to say on issues affecting the economy and federal employes. Most political workers say they expect those issues to dominate future debates between now and the election Nov. 2.

Lechner would like to make the race a referendum on Reaganomics. "Do you want to risk another two years of this economic game plan that has brought America almost to its knees?" he asked the audience.

Wolf, who never mentioned Reagan by name during the debate and whose staffers passed out campaign literature that omits Wolf's party affiliation, countered that the administration has made "tremendous progress" by reducing the prime interest rate and controlling inflation.

But neither candidate discussed federal workers, who constitute more than one-third of 10th District voters. The 10th District, which encompasses Arlington and Loudoun counties and the northern half of Fairfax County and the cities of Fairfax and Falls Church, contains more active and retired federal employes than any congressional district in the nation.

That is a topic the candidates undoubtedly will address Sept. 25 at their next scheduled debate, sponsored by the Virginia chapter of the National Association of Retired Federal Employes.