'Fast and Furious 7' -- Critical Paul Walker Scenes Were Days Away From Filming

The new "Fast and Furious" movie was scheduled to shoot key scenes with Paul Walker this week -- and on the heels of his death, several members of the cast and crew say they won't be returning to the set anytime soon ... TMZ has learned.

Sources close to the production tell us most of the actors and crew were supposed to fly to Atlanta this weekend to resume filming on Tuesday ... but they're all expecting a halt in production.

Universal -- the studio behind the movie -- hasn't announced when, or if, they'll start shooting again ... but we're told some of the main stars are too distraught to work anyway.

According to our sources ... most of this week's scenes centered around Paul, so even if Universal were to go forward ... it would need major rewrites.

Ultimately, the biggest hurdle to completing 'FF7' could be the emotions of the actors. As one source put it, "No one wants to even think about the movie. Period."