It’s an instantly engrossing, sit-up-straight moment in The Texas Chainsaw Massacre when the hulking goon Leatherface first leaps from behind a door with his weapon of choice.

As its snarling, start-up roar precedes a nightmarish lunge at poor Jessica Biel, it seems this remake of the nearly 30-year-old cult classic will kick its fun and intensity up to entertainingly giddy levels.

No such luck. Even those so enamored with movie blood that they recognize the person credited with creating the splatter effect likely will be numbed and bored by the time Chainsaw runs out of gas. Said depletion comes long before the end credits.

It’s too bad, as it’s a remake not without memorable visuals, a handful of macabre, original ideas and some B-movie jumps. That it solicited the largest, loudest chain-reaction scream I’ve heard in a movie theater since The Blair Witch Project certainly speaks to the vibe it creates.

Speaking of Blair Witch, remember how they ended up stuck in a sort of geographical loop? Even if it’s not supernatural, it’s here, too. As Biel runs screaming through what must be the entire state, it truly does feel like she’ll never escape. The dusty back roads, filthy trailers and desolate meat-packing plants are like a grotesquerie in the 10th level of hell.

And although it still was made on the cheap, it looks like $40 million bucks — think a yellowing, decayed autopsy photo crossed with the sunny cinematography of a beer commercial. Biel’s hourglass figure, barely concealed in a white tank-top and hip-huggers, is shadowed, lit and shot with great care.

A camera pulling back through a gaping bullet wound and a brief crane shot of an emptied colostomy bag keep the B-movie squirms alive. (The film was shot by Daniel C. Pearl, who also worked on the original.)

Before we’re introduced to the victims, director Marcus Nispel shows us the kill floor via grainy crime-scene footage. It sets a creepy tone, countered by devil-may-care sexin’, druggin’, boozin’ and rock ’n’ rollin’ going on in a full-sized van by five kids on their way to see Skynyrd in 1973. That band’s plane crash seems tame compared to what these kids will go through.

After almost turning a hitchhiker into roadkill, the group gives her a lift, only to watch her pull a gun and blow her cranium all over the back of their ride. If the close-ups of brain matter in Pulp Fiction grossed you out, stay away.

In a move that’s noble, but certainly offensive to the five senses, they keep the body in the van until they can speak with the county sheriff. Unfortunately, Johnny Law is a drunk, twacked-out psychopath played with a perfect over-the-top pitch by R. Lee Ermey of Full Metal Jacket fame.

It all leads to a Southern gothic house filled with inbred loons and weirdoes, most with buck teeth, some with a bloodlust.

Chainsaw occasionally passes the litmus test, generating enough tension for us to play along willingly as the pretty pieces of meat walk right into the room they shouldn’t. And there are nice touches with Leatherface (Andrew Bryniarski), namely when he wears a certain, um, “face mask.”

But after awhile, the gore and the game plan (run, chase, maim, repeat) cease to be campy and grow oppressive. Shaming Lola, Biel runs so far, so long and into so many traps that it wouldn’t seem unlikely for someone to just reach around the corner and whap her with a frying pan. It becomes a series of “What would you do?” scenarios, and her marathon and the movie drag on.

And after its absurd conclusion, this Texas Chainsaw Massacre feels exactly like the original — likely to spawn another slate of (largely) stupid sequels.