My 1994 nissan pathfinder won't start the battery is fine all the lights come on so I know that its not the battery... it cranks but it don't turn over someone know please let me know

my 1994 nissan pathfinder wont start the battery is fine all the lights come on so i know that its not the battery.... it cranks but it dont turn over someone know please let me know
Might want to check the fuel system