If Jimmy Carter's come-from-behind Virginia strategy is to work, the president will need more help from the Democratic party's conservatives and stronger leadership from its titular head, Lt. Gov. Charles S. (Chuck) Robb, many party workers say.

With Carter now said to be running better than expected in the only southern state he lost four years ago, pressure is building on both Robb and members of the party's right wing, many of whom have been sitting out the campaign, to speak out more forcefully for the president.

"We think we're starting to get some of them, but I'm not going to sit here and tell you they're loyal and enthusiastic for Jimmy Carter all the way," says Bill Albers, coordinator for the Carter-Mondale campaign in Virginia. s

Robb, the party's only statewide office holder and its most likely gubernatorial nominee next year, has touted the Democratic party in many appearances around the state. He and his wife, Lynda Johnson Robb, have taken turns escorting First Lady Rosalynn Carter on five quick campaign visits around the state, and the couple hosted a private $250-a-head fund-raiser with Mrs. Carter at their McLean home earlier this week.

But even some of Robb's most loyal followers say they wish he would take a tougher stance on Carter's behalf. They say that while criss-crossing the state, Robb seldom makes direct appeals for the president and never, never criticizes Ronald Reagan, the GOP nominee.

Almost wistfully, they long for Robb to be "more like Dick Davis," the Virginia Democratic party chairman who has increased his name recognition -- and enhanced his own political aspirations -- by whipping up anti-Reagan sentiment. And they note that while Robb is being typically low-key, Republican leaders such as Gov. John N. Dalton and State Attorney General J. Marshall Coleman, Robb's likely guernatorial rival in 1981, have stumped for Reagan like true believers.

"The Carter people have been really dissatisifed with Robb, and I think it will come back to haunt him," said one Washington political aide. Another Carter worker, a woman involved in the Northern Virginia campaign, sighs: "Chuck is a Democrat, and I think it would be in his own best interest to speak out more for the president."

George Gilliam, executive director of the state party, defends Robb's "reserved manner" and says it should not be interpreted as a lack of support for Carter. "Not everyone has the same cheerleader style that Davis has used. I'm very happy with what Chuck has done, expecially when you consider that for years and years state office holders in Virginia have just not gotten involved in federal campaigns."

An aide to Robb said the lieutenant governor has done everything he has been asked to do for the Carter campaign but has a longstanding policy against making personal attacks on my political candidate.

Robb, even his critics concede, is in an awkward position for someone who wants to be governor in an extremely conservative state. "As a Democrat, he's got to campaign," says political analyst Larry Sabato. "But he's also got to make it clear that Jimmy Carter is not in his prayers at night."

Sabato, assistant professor of government and foreign affairs at the University of Virginia, says Robb's not the only Democrat who could be doing more for the president. Both Sabato and Carter campaigners say endorsements by local and state legislative leaders, particularly in conservative areas of the state, could be a boon to the campaign.

Yet, Sabato says, "most of the Virginia General Assembly Democrats, both in the House and the Senate, have not taken a really active role in the campaign, and probably less than half have made a formal endorsement of Carter." In the House of Delegates, were roughly a third of the members are staunch conservatives, "it may be a minor victory if they don't defect to the GOP."

This lukewarm or nonexistent involvement of influential Democrats has Carter strategists worried, particularly now that their own poll, which Republicans dispute, shows that Reagan's lead in the state is slipping.

Northern Virginia Democrats, hoping to capitalize on that, will hold a news conference to endorse Carter on Monday and Albers says more such public displays of support can be expected elsewhere in the state. Democrats in the Tidewater area already have lined up behind the president after strong pressure from labor and other groups.

Legislators from Virginia's 4th and 9th congressional districts, in the southwestern and southeastern portions of the state where party loyalty is prized, have had no problems talking up Carter's reelection. "I'm a Democrat, and he's a Democratic president," says Del. Erwin (Shad) Solomon (D-Bath), who doesn't worry that his support for Carter will hurt his own campaign to be attorney general. "People in Virginia will weigh the man, and backing the head of your party will only offend hard-core Republicans who wouldn't vote for you anyway."

Such endorsements, however, draw little attention in the Washington suburbs, according to Arlington Del. Warren G. Stambaugh. "I was in Williamsburg this weekend and a Portsmouth delegate said something or other and was all over the tube," he said ruefully. "If I killed (Republican-backed Arlington County Board chairman) Walter Franklin, I might get on TV . . . maybe."