"ZOOT SUIT," a movie directed by Luis Valdez from his own successful play, opened this spring in 30 cities in the Southwest and immediately went nowhere fast. Screened in Washington for a Spanish-speaking audience, it drew polite applause, but no booking. A flutter of interest generated by the stage productions in Los Angeles and New York died away, and so did the potential of movie publicity built on a hoped-for "fashion angle."

"It's in the studio's hands now," said Luis Valdez from little San Juan Bautista, Calif., where he founded El Teatro Campesina repertory company 17 years ago and is now at work on a new play. "The movie still turns up here and there, but in fact it never took off. The studio was dismayed at what happened in the Southwest, and that was to be the foundation of the national campaign."

A spokesman for Universal Studios analyzed the fate of the film this way: "Apparently the people who saw it didn't think it was any good."

They had reason enough. As a movie, "Zoot Suit" tries to be too many things, among them a 1940s musical, a courtroom thriller and a parable of Chicano pride. It wears its ethnic bravado on its sleeve, as did the Mexican-American "zooters" of Los Angeles in 1942, with their voluminous jackets, pegged pantaloons and floor-length key chains.

As a musical, it never gets up a head of steam; as a courtroom thriller it falls short; and as for parable--well, if satire is what closes Saturday night, parable is the matinee.

And yet, and yet . . . "Zoot Suit" is a difficult film to put out of mind.

Something about it sticks, and that something is the quality of pachuco--a Chicano style of bravura posturing and ethnic pride both bizarre and touching.

The story turns on the Sleepy Lagoon murder case of 1942, a year during which patriotic Los Angeles apparently saw itself besieged by a zoot-suited, switch-blade knife-carrying foreign element. When a Mexican-American youth was found murdered at a local reservoir and lovers' lane, 600 zooters were rounded up by police. After an excessively speedy trial, 12 were sentenced to life in San Quentin. They were out in 18 months--but not before the American melting pot had boiled over with intolerance.

Luis Valdez has reduced the number of defendants to four, and centered his story on the natural leader among them, Henry Reyna (Daniel Valdez). Reyna intends to join the Marines until the charge of murder changes all that. Double-crossed by Anglo society, he returns to full pachuco style, with its jive talk and fatalism. Like most tragic heroes, he is ambivalent about the role thrust upon him.

To underscore the difficulties of being Henry Reyna--or any minority at any time--Valdez has supplied him with a rivetingly dramatic alter ego known as "El Pachuco." He is a sort of mythic zoot-suiter, an ethnic conscience who periodically stops the movie action in order to scold, mock and otherwise instruct Reyna about the course of true Chicano manhood.

Edward James Olmos--who played an urban Indian in "Wolfen" and is currently being seen as a colleague of Harrison Ford's in "Blade Runner"--takes some getting used to as El Pachuco. At first he seems a brutally unsympathetic caricature: a debased Jiminy Cricket, crooning "Marijuana Boogie" in Reyna's ear, urging him to die for his dignity, to distrust whites, Jews and a legal system intent on eradicating him as if he were a grease spot on the American flag.

But before you know it, Olmos and El Pachuco dominate the film. You can't take your eyes off that cruel face with its mocking eyes, and he comes to be a most effective tour guide through a landscape where pride rises like a mountain above a plain of despair.

Given such a compelling character and memorable performance, why did the movie "Zoot Suit" flop?

Doubtless because its color photography is turbid, there is an annoying low-budget echo in the sound track, and the story line is as busy as grandmother's wallpaper.

Like a singing tap-dancer, "Zoot Suit" not only gets on your nerves, but it runs out of breath.

But then, of course, you have to take somebody else's word for that. No theater in Washington has booked the picture, so it is quite unlikely there will be any divergence of opinion.

Meanwhile, Luis Valdez is polishing up a new play. He works all night and sleeps during the day. It is called "Bandido," a story based on the notorious bandit Tiburcio Vasquez, who terrorized California in the 1870s. The ending will not be a surprise, apparently, since Vasquez "was born in 1835, and hanged in 1875."

Does Valdez hope "Bandido" will be made into a movie?