Robert Taylor, who was fired last Friday after seven years as general manager of WHUR-FM (96.3), lost his first attempt at legal restitution when a judge denied his motion for a temporary restraining order against the station's owner, Howard University. According to his lawyer, Taylor now plans to request a preliminary injunction, but the date for that hearing has not been set.

Taylor's dismissal comes at a time when WHUR, the area's leading black-owned radio station, has a solid niche in the market at fifth place and substantially increased revenues. A few months ago Howard ordered an audit of the station, but it is not clear whether there is a connection between Taylor's firing and the audit's findings, and the university declined to discuss the reasons for his dismissal. "Robert Taylor has been terminated and we are not giving any further information," said a university spokesman.

Taylor, who started his radio career at the station as a student intern in 1972, said he was "surprised" at the action. "I had never been given any formal complaint from the university," he said. At the meeting where he was told of his termination by Dr. Owen Nichols, the vice president for administration, Taylor said, "I told him I had not done anything wrong and was not going to resign. He then informed me that I would be terminated. And I had one hour to leave."

In the affidavit Taylor filed in Superior Court Wednesday, he stated he had suffered "irrefutable injury" from the termination and that since his termination "I have been called and labeled a thief, a forger and in general held to low public esteem by the vendors with whom I formally transacted business and by the general public" -- referring, according to his lawyer, to general discussion about his firing.

Though WHUR seemed to have more than its share of internal problems, particularly personnel matters that have led to several legal actions in the last few years, Taylor's era was considered a success. By the end of Howard's fiscal year this past Sunday, the station had increased its net sales over last year by 42 percent, according to Taylor.

James Watkins, a former engineer at WHUR and the director of the university's Office of Satellite Communications, has been appointed acting general manager. Other Employment Notes

Award-winning reporter Nancy Lyons joined WASH-FM (97.1) this week as a street reporter, anchor and special projects producer. Lyons, 28, graduated from West Springfield High School and has worked in Raleigh, N.C., for the last 3 1/2 years. She was part of a team that won a Peabody Award in 1984, a Robert F. Kennedy Journalism Award in 1983, as well as prestigious awards from UPI, Sigma Delta Chi and Ohio State. Sick List

Fred Fiske, super-knowledgeable talk show host on WAMU-FM (88.5), will be off for two more weeks following what he described as a "minor heart attack." Dr. Jacob Katzow, a psychiatrist, will be substituting tonight, and Gail Scott, a free-lance journalist, steps in next week. A Summer Substitute

The Rev. Willie Wilson, pastor of Union Temple Baptist Church, will sit in for Cathy Hughes on WOL-AM (1450) every Monday from 7 to 9 a.m. until the station is in its new location in September. Hughes, the station owner, is expected to sign a lease any day now on a new studio a few blocks north of its 16-year-old location at Wisconsin Avenue and Reservoir Road. Marvin's Move

WNAV-AM (1430) has cut back Marvin Mandel's daily show to Tuesdays and Thursdays from 9:30 to 10 a.m. in preparation for a new show the former Maryland governor will be doing Sundays on WHFS-FM (99.1) starting Aug. 4. WNAV is also carrying President Reagan's radio address each Saturday at 12:05 p.m., as well as the Democratic response at 1:05 p.m. To Loretta With Love

WMZQ-FM/AM (98.7/1390), elected Washingtonian magazine's "Best Country Station" for the fifth straight year, is saluting Loretta Lynn for a week beginning next Wednesday. The station's own stars will be appearing at the Old Post Office Pavilion from 5 to 7 p.m. that day. WMZQ will be playing plenty of Lynn, including a replay of her 25th anniversary special, on the FM at 8 p.m. July 18, the first of her two dates at the Kennedy Center. In addition, the station has announced a shift of "American Country Countdown" to Saturdays on the AM from 10 a.m. to 1 p.m. The FM now carries the countdown on Sundays from 8 to 11 p.m. On Sunday mornings the FM schedule includes Gary Henderson with country oldies from 8 to 10 a.m., followed by hits with Jack Daniels until 3 p.m.