Mary Decker Slaney, America's greatest woman's distance runner ever but still without an Olympic medal, has no intention of quitting, at least not until after the 1992 Barcelona Games.

"The Olympics have been so elusive to me," Slaney said Friday at a press conference for Saturday's Mercedes Mile on Fifth Avenue, in which she rates as one of the favorites in the women's elite race. "If I stop trying, it's like I've given up."Slaney does not give up easily.

She didn't give up in the Olympic 3,000-meter final at Seoul, where her body ached from a debilitating virus, which has lingered for about eight weeks, and a calf injury, suffered when she was spiked during the heats.

And she didn't give up in the Olympic 1,500 final, in which she still was slowed by the weakening illness, a malady that has yet to be fully diagnosed.

She didn't get the medal that has been eluding her since becoming a world-class runner 17 years ago at age 13, but she had the satisfaction of finishing both races - a first for Slaney in the Olympics.

"After the 3,000 (the first of the two races, in which she finished 10th), my initial response was to go home," said Slaney, the American record-holder at all distances between 800 and 10,000 meters. "I didn't feel good.

"But then I thought about all the trouble I had gone through of making the team, and I'm here, and I'm not injured and I had felt good putting in the effort, although it wasn't a good effort."

So Slaney, still feeling uncomfortable physically and affected mentally by the discouraging finish in the 3,000, ran in the 1,500, finishing eighth.

"In the first event (the 3,000), I felt tremendous pressure because I wasn't 100 percent," Slaney said. "I went out too hard, but that's what I was there to do."

Going out quickly is Slaney's style. One of the rare occasions when she didn't do it was in the 3,000 final at the 1984 Olympics, and that ended up in the celebrated collision with Zola Budd in a tightly bunched pack.

This time, Slaney led early but then began to fade in the closing stages of the 71/2-lap race.

"I felt so bad those last few laps," she said. "I thought about not finishing. But I said, `I have to.'

"If I didn't, I'd be back to where I was in 1984."

She finished - but in dismay and frustration.