Flushed with enthusiasm built up by a massive public demonstration here Sunday, supporters of a proposal to extend the time for states to ratify the Equal Rights Amendment marched on the hall of Congress yesterday, but wound up a day of lobbying without enough firm votes to win approval of the proposal in the House Judiciary Committee.

Eleanor Smeal, president of the National Organization for Women (NOW), nonetheless pronounced the day a success while conceding that persuading members of Congress to change their views "doesn't work like a Perry Mason show." She said 2,000 or more ERA supporters visited every other representatives, and established an "atmosphere and momentum" that could lead to approval of the proposal later this month.

Rep. Don Edwards (D-Calif.), the leading advocate on the 34-member judiciary committee of extending the ratification time, admitted that he asked for a postponement of a vote on the issue, scheduled for today, after his latest count showed only 16 ayes, two short of a majority.

Yesterday's lobbying effort centered on a half-dozen committee members believed to be candidates for switchovers, and reconsiderations last night, no one could identify any converts.

Smeal said most of the more than 50,000 people who marched in Sunday's parade and rally returned to their homes yesterday. She predicted that, spurred by their experience here, action to promote an extension for ERA ratification would pick up in home districts.

Many of the women said that if they fail to achieve an extension from this Congress, "we'll vote them out and elect a Congress that will," as one woman put it.

The failure to win any converts frustrated and angered many of the ERA advocates, nearly all of whom were women, especially when they were told that much of the opposition to the extension centers on legal ratifications.

"You can find a legal argument to support us if you really believe in ERA," Jeanne Connelly, a lawyer from Philadelphia, told Rep. Tom Railsback (R-Ill.).

Railsback, who listened to about 100 women in an hour-long discussion, ended up where he started, however - favoring an extension of the time for ratification, along with allowing states to rescind ratification in the same extra time, a position that ERA supporters say is "a no vote."

Railsback cited the testimony of Lawrence H. Tribe of the Harvard Law School, who found he was "obliged" to support allowing discussion along with extension, and Charles Black Jr. of Yale Law School, who said it would be entirely impermissible" to extend one without the other.

Contending that "without an [WORD ILLEGIBLE] ERA is dead," another woman urged Railsback to "repeat the [WORD ILLEGIBLE] age you showed" during the Nixon's impeachment hearings four years ago.

"Forgive me if I sound hostile," another young woman said, her voice quavering, "but we have to keep asking men to give us our rights."

Dr. Allie Hixson of Greenburg, Ky., who retired from teaching English at the University of Louisville to work for passage of ERA, came away from a meeting with Rep. Romano L. Mazzoli (D-Ky.), worried that Mazzoli is "buckling under to pressure from the right-to-lifters."

She said Mazzoli, a member of the Judiciary Committee and an opponent of abortion, is "a man much troubled, caught up in the confusion between ERA and abortion," which she believes is forstered by antiabortion leaders.

Edwards, whose subcommittee approved extending the seven-year limit for states' ratification imposed by Congress when it approved the proposed constitutional amendment in 1972, said anti-ERA leader Phyllis Schlafly and other opponents are "not very accurate" when they talk about ERA in terms of gay rights and abortion.

"It's mostly about jobs, money, estates, the rights of women (thwarted) by laws that now have to be fought one case at a time."

It was believed that the only concession ERA supporters on the committee are willing to make on the extension proposal is the number of years, suggesting that something less than seven -perhaps four or three - would be acceptable.

Rep. Lamar Gedger (D-N.C.), a freshman member of the committee, promised a group of North Carolina women who confronted him on the steps of the Capitol that he would "spend some time in the law library" researching the legality of extending the time.

Gudger, who voted to ratify ERA as a member of the North Carolina state Senate but is considered undecided on extension, agreed with the women that the March 22, 1979 deadline is "so arbitrary as to be reasonable."

Jennie Knoop, 30, a music teacher and mother of two from Durham, told Gudger that "the legal principles of an undeclared war and a peacetime draft were not so clear to me," and that she believed the Constitution could "withstand" an extension of the time for ratification.

Gudger agreed, saying, "It's not what I want, but how I want to see it fulfilled." He added that a three-year extension "makes more sense than seven" because "a decade is a reasonable time" to achieve the contemporary consensus envisioned for changing the Constitution.

Another committee member who conducted a public forum on the question was Rep. Hamilton Fish (R-N.Y.) who along with Rep. William S. Cohen (R-Maine) are the only Republicans among 11 minority members on the committee viewed as favoring the extension.