Whatever juice is left in the “Cop” franchise or in the once unstoppable career of Eddie Murphy peters out ignominiously in this poor excuse for a sequel. If Murphy feels energized by returning (after seven years) to the role of Detroit cop Axel Foley, a fish out of water in the hills of Beverly, you can’t tell it from his slapdash performance. The clown prince who exploded in 48 HRS., Trading Places and the first “Cop” in 1984 is now the preening fat cat who squanders his gifts on sexist japes (Boomerang) and vile vanity productions (Harlem Nights).

As directed by Martin Brest in the original “Cop,” Murphy created a real character in Axel. This time, as directed by John Landis — whose talents seem equally exhausted — Murphy merely paints Axel on. The murder of Axel’s Detroit chief is a cue for tears. When he chases the killer (Timothy Carhart) to Los Angeles and reunites with bumbling cop Billy Rosewood (Judge Reinhold), it’s time for laughs. Bronson Pinchot turns up to reprise his cameo as Serge, the fey, marble-mouthed gallery dealer who has taken to manufacturing an all-purpose boutique weapon that also serves as TV, CD player, camcorder and microwave.

Gimmicks replace characterization at every turn. Most of the film is set in a theme park, where the killer’s security force has wrested control from the owner, benign Uncle Dave (Alan Young), to run an underground counterfeiting operation. It could have been Die Hard in Disneyland since Die Hard writer Steven E. de Souza did the script. But even the special effects — Axel saves kids from falling off a spider ride — are tacky and halfhearted. Murphy shoots bad guys, uses the f word more times than Madonna, comes on to a babe (Theresa Randle) and even dresses up as an elephant and bumps a kid (he calls him a “little muthafucka”) into a fountain to show he hasn’t gone soft like Ah-nuld in Last Action Hero. But Murphy is hawking a memory and trying to make us buy it as the genuine article. It’s no sale.