In 1978, Eastwood and Reynolds appeared together on the cover of Time as the reigning male superstars. If "City Heat" had been made that year, it would have been a superblockbuster.
But by 1984, Reynolds' career was already declining (too many insipid "Cannonball Run" movies.) Eastwood -- who after "Dirty Harry" never worked with major co-stars -- may have finally said "yes" to co-starring with Reynolds because he was clearly the bigger star in 1984. But even Eastwood was starting to age.
All the problems others have related here are true, plus one more: Reynolds was hit in the face by a stunt man with a real chair while filming the opening diner fight scene. Reynolds' jaw was broken and he had a severe medical condition causing pain, headaches, and dizzyness. Reynolds was a trouper and finished the movie (he is quite funny in it), but one of the reasons the movie is so short and incoherent is that the injured Reynolds couldn't work very long in the film (notice: in the final fight, "Reynolds" is wearing a wolf mask -- because that's not Reynolds.)
"City Heat" opened at Xmas against "Beverly Hills Cop" and new star Eddie Murphy cleaned the clocks of old stars Eastwood and Reynolds . Reynolds would never be a top star again. Adding insult to injury, the ad tag line "The Heat is On!" first used by "City Heat" was shifted to "Beverly Hills Cop" when "City Heat" disappeared from theaters.
It's too bad, really. Once upon a time, Eastwood and Reynolds were both co-equal major superstars, and it would have been exciting to see them paired together. The opening diner scene and a few later exchanges give us a tantalizing glimpse of how good "City Heat" could have been had it not be jinxed from the start.
