Former president Gerald Ford was pulled into a secret strategy meeting in Arlington yesterday called by Virginia Republicans worried that GOP gubernatorial nominee J. Marshall Coleman is on the verge of turning over the 12-year GOP rule in Richmond to Democrat Charles S. Robb.

Ford, who did not stay to hear the expressions of concern voiced by party officials, said he was aware that Coleman is "behind in the polls" in his race against Democrat Charles S. Robb and so he "exhorted the troops."

The thrust of the 90-minute meeting, said sources who attended, was that the election is "on the line."

Speakers included Kenneth Klinge, a veteran Republican fieldworker dispatched by the White House to shore up the campaign, Republican national committeeman William Stanhagen and state party chairman Alfred B. Cramer III. They talked about the latest poll conducted by Richard Wirthlin, President Reagan's personal pollster, which shows Coleman trailing Robb by five points. They also discussed the failure of local volunteers to use the sophisticated direct mail and phone banks facilities that have aided the party's rise in Virginia in the last decade.

State Sen. Wiley F. Mitchell of Alexandria said the speakers insisted that "the race is winable." But Mitchell added: "You'd have to be blind not to be concerned."

Ford said he agreed with those who say the Coleman-Robb race is "a referendum on the Reagan administration."

"After all, Marshall Coleman is a very strong advocate of President Reagan's economic policies and other policies, and the president carried Virginia overwhelmingly in 1980," said Ford. "So, yes, to a certain extent, it is a referendum."

The former president's observation pleased a beaming Coleman, who increasingly is tying his hopes of defeating Robb to his close identification with the popular president.

Ford's first appearance yesterday was at a $1,000-a-couple reception at the Arlington home of former congressman Joel T. Broyhill, an 11-term GOP representative from Virginia's 10th District. "Whether we like it or not," Broyhill said, "if Marshall Coleman doesn't win, the press and some other people will view it that way."

The GOP, worried about polls showing Coleman trailing Robb, will bring out its superstar in 9 days when Reagan himself will join Coleman on the campaign trail. The president tentatively is scheduled to appear at a rally in Virginia Beach on Oct. 27.

Ford's statement was the latest in a series of comments by ranking national Republicans supporting Coleman's view that a vote for Coleman is a vote for Reagan. On Friday night, Sen. Howard Baker (R-Tenn.) also used the word "referendum" in urging a Roanoke audience to support Coleman.

As Coleman further tightens his hold on Reagan's coattails, Robb appears to be moving away from his own earlier strong support of the president. During a statewide televised debate Thursday Robb criticized Reagan policies on Social Security, the draft, and tuition tax credits for private schools.

Coleman yesterday also wrote to Robb and suggested that the two campaigns share the cost of broadcasting the debate to areas where it has not been carried. "We'll think about it," said Robb campaign manager David Doak, who said Robb had not yet seen the invitation.

Ford's appearances yesterday -- another was at a $100-a-person reception at the Sheraton National Hotel in Arlington -- climaxed a week of celebrity fund raising by both candidates.

Robb was the beneficiary of appearances by his famous in-laws and a former Miss America. Wednesday night, Kentucky Gov. John Y. Brown and his wife Phyllis George, a former Miss America, were guests at a fund-raising reception that attracted 500 people to the Alexandria river front home of developer Gerard Halpin.

"We both outmarried ourselves," Robb joked to Brown, pointing out that his wife, Lynda, daughter of former president Lyndon B. Johnson, and Mrs. Brown are natives of Texas.

But the star of that evening once again was Robb's mother-in-law, Lady Bird Johnson, who said she is helping in the campaign largely for the chance "to be with my grandchildren, to serve as a babysitter."

Rounding out the family affair for Robb was Luci Johnson Nugent, Lynda's younger sister, who campaigned throughout the state for four days last week.