The most a show like "Lie Detector" can hope to be is irresistibly awful, and while it's awful all right, this new syndicated program may prove highly and fatally resistible.

Channel 9 is taking the unusual step of sneak-previewing the show, which normally will air week nights at 7:30, in the primest of prime time--Sunday night at 8, right after "60 Minutes" and pre-empting CBS's "Archie Bunker's Place" in this market. So viewers will be able to watch F. Lee Bailey turn Barnum and emcee a half-hour of grotesquerie in which Melvin Dummar, Ronald Reagan's barber and a convicted murderer let themselves be hooked up to a polygraph machine for a hootable exercise in living excruciation.

Tromping, flouncing and doing the merry minuet on ground already broken by "The People's Court," this new show finds Old Bailey playing huckster right from the start. "What you are about to witness here is real," he tells viewers, stretching a term that TV already has stretched beyond recognition. Yes, three people have agreed to submit to televised lie detector tests in the hope of proving some allegation either true or false. Poor Melvin Dummar is first up. He insists again that the will he says Howard Hughes gave him is legitimate, and then he is strapped into the clutches of the polygraph.

Emerging from behind a sliding door straight out of "Star Trek," the cooperative Dummar is greeted by Bailey with this stern zinger: "Melvin Dummar, according to these charts, there's not one ounce of truth in anything you have said about the will." Melvin looks numbed. "These charts are so bad, they would be excellent for freshman students in polygraph school just to show them how bad it can get," Bailey scowls. The way he keeps on, you half expect him to leap at Melvin and wrestle him to the ground.

In an earlier version of this pilot, the next guest was Zsa Zsa Gabor, who was asked to prove via polygraph that she hadn't married (and married and married) only for money. Or something. Zsa Zsa had asked before the test if it would hurt, and Bailey told her, "Just a mild electric shock. You'll enjoy it." But this segment subsequently was removed because of reported irregularities in Zsa Zsa's charts, and replaced with a segment featuring Harry Drucker, President Reagan's barber, who swears Reagan does not dye his hair ("America wants to know," Bailey had said). The machine bears him out.

Of course it's stated up top that these machines are fallible.

Finally, Harry Siegler, who was urged by his lawyers to plead guilty to a murder charge just before a jury returned a verdict of not guilty, and thus is now serving 20 years in a Richmond, Va., prison, takes to the lie detector in an effort to prove he really didn't slit the throat of a grocer he was helping to rob. But Bailey looks at not one but two sets of squiggly lines and says, "Harry Siegler is still lying."

On upcoming programs, according to the show's publicity, Gaylord Perry will try to prove he didn't throw the spitball that got him suspended from baseball and a man will deny he cheated on his wife. Channel 9, which already airs the egregious embarrassment "Couples" at 11:30 week nights, seems to be specializing these days in the tackier forms of trash television, having a high old time at the bottom of the barrel, and it's almost tantalizing to wonder how much lower the station can go. For now, "Lie Detector" holds the record.