Yep it's the starter. It starts when it cold, but not warm. had a similar problem in a an Olds I used to have.
And when I read this title all I could think of, well . . . "Click" is better then "BOOM!"
1992 Ford Ranger STX 4x4
4.0 Liter (6 cylinder)
"When I grow up I want to be an F150"