It’s hard to figure what Justin Lin was thinking as he assembled this third sequel to The Fast and the Furious. Not that it is unnecessary. Looking at it from the persective of Vin Diesel’s career, which fell into a slow stall after the first movie made him an unexpected star, there’s reason to go back to this well. Or gas pump, whatever. Paul Walker has been luckier (or better managed) but even while he’s made entertaining movies, only 2 Fast 2 Furious hit like his first team-up with Diesel.

Ironically, this movie is like a stalled career edited down to two hours. It hits the ground roaring with a hell of an opener as Dom (Diesel), lover Letty (Michelle Rodriguez, grimly overplaying) and their assorted crew steal gasoline in the Dominican Republic. The setpiece ends with a barely-controlled downhill chase, but while Dom arrests his own descent, the movie just keeps going.

The heat is on Dom, so he bolts, leaving Letty with little more than hope and a stack of paper. But something happens to her and Dom ends up back in LA, looking for a drug runner named Braga as loose cannon FBI Agent Brian O’Conner (Paul Walker) is -gasp!- on a parallel investigative track.

The two team up again, perhaps more uneasily than the first time, and tune up their respective sleds to win a spot on Braga’s elite drug-running street race squad. Yeah, it’s ridiculous; this isn’t an adaptation of a feature from The Economist. It’s macho bullshit, but as the original movie proved, macho bullshit can be a lot of fun as long as it’s at least slightly sincere.

This ain’t.

This is a movie where the second big setpiece — Dom and O’Conner’s qualifying street race — is a bit more lame than the first. It’s one where the highlight of that race might be the Burnout video game-style GPS boxes guiding the racers. And it’s a movie with Action Subtitles! that actually move across the screen so viewers don’t get bored by the words. (After these, regular subtitles will look as lame as stiff action figures did after the debut of the kung-fu grip.)

Lin at least has the courtesy to make some of it funny; the subtitles are more entertaining than the action. His vision of LA street racing culture is so tongue in cheek it might be miming a blowjob. And in one moment when Diesel isn’t mining his tough/sensitive schtick for lost dramatic gold, a surprising skill is revealed: he’s the Skid Whisperer! We learn this when Dom processes skid and burn marks through the incredible power of his mind to recreate an accident.

And give Rodriguez, Walker and everyone else some credit, as they gamely attempt to live up to the script’s Shakespearian overtones. It’s not their fault that Lin makes their tender moments laughable by shooting them in Hero Vision or intrusive close-up. Nor is it their fault for being sandwiched between action scenes that rattle and clank like a rusted Pinto.

Finally, the movie tries to kick into high gear with a drawn-out finale that isn’t satisfying even by the straightforward expectations created by the rest of the series. All we want to see is cars going very, very fast and crashing, and some blowing up, and cutaway shots of Vin and Walker grimacing. Or hooting. It’s not rocket science.

But the would-be showstopper takes place in a constricted tunnel, which means that a lot of the racing is, at the very least, computer-enhanced. Even according to the low standards of the big dick action movie, that is lame. The cars look great, but if any given episode of Top Gear is high-class automotive porn, this might be a stained stroke mag hidden behind a gas station toilet.

3 out of 10